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Foliar Burn and Wheat Grain Yield Responses Following Topdress-Applied Nitrogen and Sulfur Fertilizers
Journal of Plant Nutrition
Abstract
The most common fertilizer sources for topdress nitrogen (N) applications to winter wheat (Triticum aestivum L.) in Virginia are a urea ammonium nitrate (UAN) solution (30-0-0) or a UAN solution with added sulfur (S) (UAN-S; 20-0-0-4). However, there are some concerns regarding leaf burning following foliar N applications, particularly at later growth stages. An experiment was conducted from 1999 through 2002 to evaluate and quantify foliar burn associated with various topdress-applied N sources, any subsequent effect on wheat grain yield, and any yield response to added S. Ammonium nitrate (AN; 34-0-0), UAN, UAN-S, and ammonium sulfate (AS; 21-0-0-24) were topdress-applied at either GS 30 or 32. Following the GS 30 and 32 foliar applications, digital images were obtained from each plot and pixel analysis was used to estimate the percentage of foliar burn. At GS 30, foliar burn increased with increasing N rate with no difference in the percentage of burn being observed between sources. At GS 32, foliar burn again increased with increasing N rate; however, UAN-S resulted in significantly greater foliar burn than UAN at both N rates. Despite the increased foliar damage that occurred when UAN-S was topdress-applied at GS 32, there was no reduction in grain yield compared with UAN or either of the soil-applied sources at either growth stage. Although there was no evidence of a grain yield response to added S in this study, many soil types common to the Coastal Plain of Virginia are likely to lack sufficient S for optimum winter wheat production.
... The principal sources of macro-and micronutrient fertilizers and their solubility have been listed in Tables 1 and 2. The concentrations of macro and micronutrients major salts used for foliar spray are presented in Table 3. Selecting appropriate sources of inorganic fertilizer for foliar sprays is not only important for uptake efficiency but also for foliage burning. Considerable differences have been reported among fertilizer sources in burning foliage with foliar application of inorganic fertilizers, especially N (Phillips and Mullins, 2004). Phillips and Mullins (2004) reported that any foliar N solution applied to cereal plants may result in visual damage described as leaf "scorching", "burning", or "tipping" even at low rates of N application (15 kg ha −1 ) (Gooding and Davies, 1992). ...
... Considerable differences have been reported among fertilizer sources in burning foliage with foliar application of inorganic fertilizers, especially N (Phillips and Mullins, 2004). Phillips and Mullins (2004) reported that any foliar N solution applied to cereal plants may result in visual damage described as leaf "scorching", "burning", or "tipping" even at low rates of N application (15 kg ha −1 ) (Gooding and Davies, 1992). The risk of foliage burning is more likely when the N source is something other than urea, such as ammonium nitrate or ammonium sulfate (Alkier et al., 1972). ...
... A positive relationship between leaf injury and yield depression of soybean by the various NPKS materials was noted, especially when the fertilizer materials were applied during midday rather in the early morning or late afternoon hours (Poole et al., 1983). Phillips and Mullins (2004) reported that foliar application of 34 or 67 kg N ha −1 at GS 30 or GS 32 (second node visible) in wheat applied by UAN or UAN-S, leaf burn increased with increasing N rate; however, no effect on grain yield was observed for ether UAN (30-0-0) or UAN-S (20-0-0-4) compared with soil applied fertilizers at either N rate. In addition, no difference in leaf burn between the two foliar sources was observed at GS 30. ...
Essential plant nutrients are mainly applied to soil and plant foliage for achieving maximum economic yields. Soil application method is more common and most effective for nutrients, which required in higher amounts. However, under certain circumstances, foliar fertilization is more economic and effective. Foliar symptoms, soil and plant tissue tests, and crop growth responses are principal nutrient disorder diagnostic techniques. Soil applications of fertilizers are mainly done on the basis of soil tests, whereas foliar nutrient applications are mainly done on the basis of visual foliar symptoms or plant tissue tests. Hence, correct diagnosis of nutrient deficiency is fundamental for successful foliar fertilization. In addition, there are some more requirements for successful foliar fertilization. Foliar fertilization requires higher leaf area index for absorbing applied nutrient solution in sufficient amount, it may be necessary to have more than one application depending on severity of nutrient deficiency. Nutrient concentration and day temperature should be optimal to avoid leaf burning and fertilizer source should be soluble in water to be more effective. Foliar fertilization of crops can complement soil fertilization. If foliar fertilization is mixed with postemergence herbicides, insecticides, or fungicides, the probability of yield response could be increased and cost of application can be reduced.
... The doses of N applied to the leaves vary between 5 and 30 kg ha −1 of N [25]. Increasing the amount of N applied in foliar fertilization can cause leaf injuries and affect the metabolic activity of the damaged tissue, as well as reduce the RNf in sugarcane [16,20], [26]. ...
... The dose of 6.0 g plot −1 of N, equivalent to 60 kg ha −1 of N, was based on the best agronomic efficiency of nitrogen fertilization in sugarcane found by Santana [37]. The dose of 1.5 g plot −1 , equivalent to 15 kg ha −1 of N, was used, based on the critical limit with risk of leaf injury observed by Philips and Mullins [25]. ...
Increasing the recovery of N fertilizer (RNf) is the main challenge in managing nitrogen fertilization in sugarcane. This study aimed to evaluate the efficiency of complementary foliar fertilization in managing nitrogen nutrition in sugarcane. Four fertilization managements, combining soil (5.0 and 4.5 g plot⁻¹ of N) and foliar (1.0 and 1.5 g plot⁻¹ of N) fertilization in up to two application events (0.5 + 0.5 and 0.75 + 0.75 g plot⁻¹ of N), were compared with conventional fertilization (6.0 g plot⁻¹ of N in soil). The change from 6.0 g plot⁻¹ to 4.5 g plot⁻¹ of N reduced the RNf by 46% before the first foliar fertilization. The RNf (26%) was similar between managements after the first foliar fertilization. After the second foliar fertilization, the RNf was 38% higher than that for conventional management. The accumulation of N in the aerial part of sugarcane was similar between managements until the first foliar fertilization. After the second foliar fertilization, the accumulation of N increased by 3.5% with foliar fertilization. The biomass accumulated by the managements was similar before and after the first and second foliar fertilization. The splitting of foliar fertilization increased the accumulation of N and RNf by 22% and 24%, respectively. The fertilization management with 4.5 g plot⁻¹ of N applied to the soil, with two applications of 0.75 g plot⁻¹ of N on the leaf, obtained greater accumulations of N and RNf. Foliar fertilization increases the efficiency of fertilization and improves the N nutrition of sugarcane.
... (Girma et al., 2007).However, this can result in a considerable and quick build-up of NH4+ in tissues, which can produce leaf damage that is usually referred to as "scorching," "burning," or "tipping" and JOURNAL OF LIAONING TECHNICAL UNIVERSITY ISSN: 1008-0562 VOLUME 17, ISSUE 12, 2023 https://www.lgjdxcn.asia/ 01-11 visible damage in the form of stunted roots and leaf damage in farms (Gooding and Davies, 1992;Phillips and Mullins, 2004). Spraying urea to open flowers has also been associated with negative outcomes (Brown, 2001;Nelson and Meinhardt, 2011), which may be due to the urea's disruption of pollen tube growth directionality and decreased efficacy of fertilization. ...
... When high rates of urea are applied under leaves, excessive foliar damage may reduce grain yield (Phillips and Mullins, 2004).Various factors cause burning effect including timing and temperature. For instance, when liquid fertilizer is applied between the hours of 8 a.m. and 5 p.m., foliar burn damage is typically severe and can be reduced when these periods are avoided (Poole et al., 1983). ...
Urea applied directly to the soil is mostly lost through volatilization and leaching. Foliar spraying is thus a potential method to increase the effectiveness of nitrogen utilization, which raises crop output. To ascertain the impact of various urea foliar application concentrations on triticale production and yield components, a field experiment was carried out. During the Rabi season of 2020-2021, An investigation was conducted at the Research Farm of Agriculture University Peshawar. The experiment followed a structured design with three replications of (RCBD). The factor encompassed twelve distinct foliar concentrations of urea dissolved in water. These concentrations were subsequently applied to the crop during its tillering and booting stages. The concentration levels were designated as follows: T1 (control) at 0%, T2 at 1%, T3 at 2%, T4 at 3%, T5 at 4%, T6 at 5%, T7 at 6%, T8 at 7%, T9 at 8%, T10 at 9%, T11 at 10%, and T12 at 11%. The results revealed that the maximum plant height (128.10 cm), spike length (16.80 cm), spikelets spike-1 (28.78), grains spike-1 (63.13), 1000 grains weight (53.24 g),biological yield (12466 kg ha-1), grain yield (5423.2 kg ha-1), harvest index (43.50) and seed protein contents (18.11 %) were observed at 6% urea foliar application. Based on the above result it is concluded that urea foliar application @ of 6% found best to be used for improving yield without any harmful impact.
... (Girma et al., 2007).However, this can result in a considerable and quick build-up of NH4+ in tissues, which can produce leaf damage that is usually referred to as "scorching," "burning," or "tipping" and JOURNAL OF LIAONING TECHNICAL UNIVERSITY ISSN: 1008-0562 VOLUME 17, ISSUE 12, 2023 https://www.lgjdxcn.asia/ 01-11 visible damage in the form of stunted roots and leaf damage in farms (Gooding and Davies, 1992;Phillips and Mullins, 2004). Spraying urea to open flowers has also been associated with negative outcomes (Brown, 2001;Nelson and Meinhardt, 2011), which may be due to the urea's disruption of pollen tube growth directionality and decreased efficacy of fertilization. ...
... When high rates of urea are applied under leaves, excessive foliar damage may reduce grain yield (Phillips and Mullins, 2004).Various factors cause burning effect including timing and temperature. For instance, when liquid fertilizer is applied between the hours of 8 a.m. and 5 p.m., foliar burn damage is typically severe and can be reduced when these periods are avoided (Poole et al., 1983). ...
Urea applied directly to the soil is mostly lost through volatilization and leaching. Foliar spraying is thus a potential method to increase the effectiveness of nitrogen utilization, which raises crop output. To ascertain the impact of various urea foliar application concentrations on triticale production and yield components, a field experiment was carried out. During the Rabi season of 2020-2021, An investigation was conducted at the Research Farm of Agriculture University Peshawar. The experiment followed a structured design with three replications of (RCBD). The factor encompassed twelve distinct foliar concentrations of urea dissolved in water. These concentrations were subsequently applied to the crop during its tillering and booting stages. The concentration levels were designated as follows: T1 (control) at 0%, T2 at 1%, T3 at 2%, T4 at 3%, T5 at 4%, T6 at 5%, T7 at 6%, T8 at 7%, T9 at 8%, T10 at 9%, T11 at 10%, and T12 at 11%. The results revealed that the maximum plant height (128.10 cm), spike length (16.80 cm), spikelets spike-1 (28.78), grains spike-1 (63.13), 1000 grains weight (53.24 g),biological yield (12466 kg ha-1), grain yield (5423.2 kg ha-1), harvest index (43.50) and seed protein contents (18.11 %) were observed at 6% urea foliar application. Based on the above result it is concluded that urea foliar application @ of 6% found best to be used for improving yield without any harmful impact.
... Crude protein (CP) and relative feed value (RFV) of alfalfa under different urea concentrations in 2016 (mean ± SD a ; n = 3) a SD is the standard deviation b N0, N1, N2, N3, N4, N5, N6, N7 and N8 represent the urea concentrations (% by weight) of 0, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 1.0%, 2.0% and 3.0%, respectively c The crude protein (CP) and relative feed value (RFV) of alfalfa under different fertilizer concentrations followed by different lowercase letters in the same column are significantly different at P < 0.05 using one-way analysis of variance Treatment 162.3a ± 14.1 Table 5 Crude protein (CP) and relative feed value (RFV) of alfalfa under different urea concentrations and fertilization methods in 2017 (mean ± SD a ; n = 3) a SD is the standard deviation b C0, C1, C2, C3, C4 and C5 represent the urea concentrations (% by weight) of 0, 0.05%, 0.1%, 0.2%, 0.3% and 0.4%, respectively c The crude protein (CP) and relative feed value (RFV) of alfalfa under different urea concentrations followed by different lowercase letters in the same column are significantly different at P < 0.05 using one-way analysis of variance. The crude protein (CP) and relative feed value (RFV) of alfalfa under different fertilization methods followed by different uppercase letters in the same row are significantly different at P < 0.05 using independent sample t test 4Ba ± 7.7 198.1Aa ± 23.6 170.7Aa ± 17.7 220.1Aa ± 54.9 211.6Aa ± 30.5 leaves resulted in the greater penetration of urea as well as osmotic pressure, which led to more serious leaf damage (Fernandez and Eichert 2009;Phillips and Mullins 2004). The damaged leaf rate of alfalfa at urea concentrations of 2%-3% reached 90% 3 days after fertilization. ...
... Spraying a urea solution of 2%-3% could even cause a remarkable reduction in alfalfa yield, which might be due to the obvious leaf damage resulting in leaf dropping. In contrast to our results, the yield of wheat harvested with grain as the final matter was less affected by leaf burning (Phillips and Mullins 2004). Meanwhile, the CP content was not affected by leaf burning and peaked at urea concentrations of 2%-3%. ...
Foliar fertilization is increasingly used to apply nitrogen (N) to alfalfa (Medicago sativa L.) at late growing season. Urea concentration is an important factor that affects fertilizer use efficiency in foliar fertilization. The purpose of this study was to evaluate the effects of urea concentration on alfalfa growth and nitrogen utilization. Furthermore, difference in N utilization between foliar and soil fertilization of alfalfa was also quantified. Urea solutions of eight concentrations ranging from 0.1% to 3% were applied in alfalfa fields through foliar fertilization in 2016. Based on the results obtained in 2016, urea-¹⁵N solutions of five concentrations ranging from 0.05% to 0.4% were used to fertilize alfalfa grown in pots through foliar and soil application in 2017. Non-fertilized alfalfa was selected as the control treatment in the two years. The leaf damage, total N content, percentage of N in alfalfa derived from labelled fertilizer (Ndff%), ¹⁵N fertilizer use efficiency (NFUE), yield and quality of alfalfa were measured. The results showed that leaf damage appeared with urea concentrations exceeding 0.4%. Increasing the urea concentration improved the Ndff% in all alfalfa organs but generally reduced the NFUE of alfalfa. The NFUE of alfalfa under foliar application had no significant difference with that under soil application in general, and reached the high values with urea concentrations of 0.05%–0.2%. Compared to the control treatment, urea application did not significantly improve the yield, total N content and quality of alfalfa. Overall, the maximum urea concentration with foliar fertilization is recommended as 0.4% for alfalfa.
... Furthermore, addresses all these issues single-handedly. Therefore, is the most effective method and a crosscut for plant nutrition under such adverse scenarios [18]. However, the sources of S for foliar application in rainfed crops and ecologies not been evaluated so far. ...
... The oxidation of elemental S is governed by microbial activity, which is strongly affected by soil moisture content and soil temperature [22]. Moreover, a plant nutrient has to travel a long path through the plant system (phloem) after its absorption and translocation through the plant roots to reach the leaves and grains, whereas in the foliar application, the nutrients needed by the plant rapidly enter the phloem and reach the target sites [18]. ...
Yield limitation and widespread sulphur (S) deficiency in pearl-millet-nurturing dryland soils has emerged as a serious threat to crop productivity and quality. Among diverse pathways to tackle moisture and nutrient stress in rainfed ecologies, conservation agriculture (CA) and foliar nutrition have the greatest potential due to their economic and environmentally friendly nature. Therefore, to understand ammonium thiosulphate (ATS)-mediated foliar S nutrition effects on yield, protein content, mineral biofortification, and sulphur economy of rainfed pearl millet under diverse crop establishment systems, a field study was undertaken. The results highlighted that pearl millet grain and protein yield was significantly higher under no-tillage +3 t/ha crop residue mulching (NTCRM) as compared to no-tillage without mulch (NoTill) and conventional tillage (ConvTill), whereas the stover yield under NTCRM and ConvTill remained at par. Likewise, grain and stover yield in foliar S application using ATS 10 mL/L_twice was 19.5% and 13.2% greater over no S application. The sulphur management strategy of foliar-applied ATS 10 mL/L_twice resulted in significant improvement in grain protein content, protein yield, micronutrient fortification, and net returns (₹ 54.6 × 1000) over the control. Overall, ATS-mediated foliar S nutrition can be an alternate pathway to S management in pearl millet for yield enhancement, micronutrient biofortification and grain protein content increase under ConvTill, as well as under the new NTCRM systems.
... As nutrient solutions applied to plants may cause damage, defined as leaf "burning", "scorching" or "tipping", the possible leaf phytotoxicity was evaluated at 7 days after the last foliar application (flowering stage). Ten flag leaves of wheat were randomly taken from each plot and compared through a photographic survey, using a modified version of the method proposed by Philips and Mullins [26]. Here, data are provided for the 2nd year trial by calculating the fraction leaf length (generally the tip) with brown color. ...
... However, damage of the flag leaf tips seems to be well tolerated by wheat, as confirmed by the appreciable yield and grain quality improvements reached by all foliar treatments, regardless of the fertilizer choice between UAN and urea. This is in agreement with the findings of several authors [11,24,26], while other studies [15,30] reported a higher threshold, i.e., 40 kg ha −1 as a single application between stages ZDS 39 (flag leaf visible) and ZDS 73 (early milk development), without compromising productivity. ...
Late-season N application through foliar spraying is recognized as an efficient agronomic practice for improving grain quality in common wheat, although the major part of N is still supplied by soil fertilization. This study assessed the impact of various N doses entirely applied by repeated foliar sprayings on wheat growth, yield and quality, in comparison with conventional soil fertilization management with a recommended dose of 160 kg N ha⁻¹ as ammonium nitrate (C-M). Doses of 96, 104 and 120 kg N ha⁻¹ as both UAN (urea-ammonium-nitrate) and urea applied by foliar spraying were evaluated in a 2-year field trial in Northern Italy in a silty loam soil with 1.7% organic matter. Here, it was demonstrated that the canopy greenness was similar in all treatments, with slight grain yield increases by the lowest foliar N dose vs. C-M. The higher N foliar doses mainly improved the grain protein content and both high- and low-molecular-weight glutenin subunits (HMW-GS, LMW-GS), particularly with urea. It is concluded that in our fertile soil, managing N fertilization exclusively through foliar spraying is feasible without compromising grain yield and ameliorating quality at the same time. Improved nutrient use efficiency and beneficial environmental effects are also expected by reducing the nitrogen load on the agricultural fields by 25–40%.
... It is often attributed to an increased salt-load on the leaf. Many studies of foliar application of fertiliser have identified leaf scorch and found that it tends to be both cumulative with multiple sprays and increases with higher concentrations of nutrients (Phillips and Mullins 2004;Syverud et al. 1980). Despite the increase in leaf scorch with high rates of foliar fertiliser applied, some studies have found no correlation between leaf burn and yield (Mallarino et al. 2005;McBeath et al. 2011;Phillips and Mullins 2004;Woolfolk et al. 2002). ...
... Many studies of foliar application of fertiliser have identified leaf scorch and found that it tends to be both cumulative with multiple sprays and increases with higher concentrations of nutrients (Phillips and Mullins 2004;Syverud et al. 1980). Despite the increase in leaf scorch with high rates of foliar fertiliser applied, some studies have found no correlation between leaf burn and yield (Mallarino et al. 2005;McBeath et al. 2011;Phillips and Mullins 2004;Woolfolk et al. 2002). Severe leaf burn has been suggested to cause decreased yields in other studies (Barel and Black 1979b;Parker and Boswell 1980). ...
Background and Aims
Although foliar fertilisation using liquid forms of phosphorus (P) is not a new concept, its adoption has been hindered by a limited understanding of the variability in performance of fluid forms of foliar P applied to broadacre crops. There is a need to identify how the surface structure of leaves influences the uptake/translocation of foliar-applied P in above ground plant parts.
Methods
This study examined the surface properties of wheat leaves using scanning electron microscopy and measured the uptake/translocation of foliar-applied fertiliser that was labelled with either 32P or 33P from both the adaxial (upper) and abaxial (lower) leaf sides into untreated plant parts.
Results
We found that the adaxial leaf surface absorbed and translocated more foliar applied P away from the treated leaf than the abaxial surface, likely related to the higher abundance of trichomes and stomata present on that side of the leaf. The recovery of the foliar-applied fertiliser varied with rate and timing of application; ranging from <30% to as much as 80% of the adaxial-applied fertiliser translocated from the treated leaf into the wheat ear.
Conclusions
This study demonstrated that the differences in surface morphological features between leaf sides influenced the absorption/translocation of foliar-applied P in the above ground plant parts. This is due to a direct effect on the foliar pathway and/or due to differences in wettability affecting both the leaf coverage and drying time of fertilisers on the leaves. Although foliar fertilisation in this study contributed less than 10% of the total P in the plant, it provided a more efficient pathway for P fertilisation than soil-applied P.
... Although the preliminary experiment ruled out the negative effects of a sole MT spray (data not shown), visual observations revealed that the combined application of foliar melatonin and foliar sulfur (S) induced slight scorching and burning effects on the plant leaves (Figure 1). One possible reason for the observed symptoms can be explained by the frequent foliar application of both substances with 2-day intervals, possibly increasing liquid density and affecting plant health (Bouranis and Chorianopoulou 2023;Phillips and Mullins 2004;Linzon et al. 1979). Moreover, the selection of the optimal growth stage has the potential to enhance S utilization efficiency post-foliar application. ...
Melatonin, a multifunctional, non‐toxic regulatory molecule, plays a crucial role in enhancing tolerance to abiotic stress, which is tightly linked to S metabolism. Despite the proven efficacy of sulfur (S) in enhancing abiotic stress tolerance, the combined effect of S and melatonin in stress mitigation remains to be elucidated. This is particularly relevant in the context of climate change, where the increased occurrence of waterlogging stress increases the risk of reduced S availability, leading to reduced yield and quality in rapeseed. The objective of this study is to examine the impact of a combination of foliar melatonin and sulfur, when administered to soil or leaves, on the response of plants to waterlogging stress. The experimental design involved the supplementation of rapeseed ( Brassica napus L.) plants with sulfur (S) to either the soil (0.2 g kg ⁻¹ ) or the leaves (300 ppm) 5 days prior to stress induction. The plants were subjected to waterlogging at BBCH–31 for a period of 7 days, preceded by a pretreatment 2 days prior to the stress with melatonin (200 μM). In comparison, untreated plants subjected to waterlogging showed a significant reduction in growth, nutrient uptake, photosynthetic activity, and sugar content but an increase in the antioxidant defense system. However, the application of melatonin significantly mitigated the adverse effects of waterlogging stress. In comparison with the control, soil‐S application exhibited higher efficacy than foliar S application in increasing plant resistance, as reflected by improved dry weight (+50%), photosynthesis (+12%), stomatal conductance (+40%), sulfur (+40%), magnesium (+59%), and reduced hydrogen peroxide (−22%) and lipid peroxidase (−26%). This combination also increased antioxidant defense by increasing catalase (+43%), glutathione reductase (+17%), ascorbate peroxidase (+47%), ascorbate (+39%), and glutathione (+40%) contents, in contrast to untreated waterlogged plants. The study underlines the potential of melatonin and sulfur as effective agents to alleviate waterlogging stress.
... To optimize nitrogen utilization efficiency, fertilizers containing ammonium (NH₄⁺) are widely used. However, excessive NH₄⁺ application can lead to its rapid accumulation in plant tissues, causing root stunting and leaf damage [2,3]. NH₄⁺ toxicity has long been a significant challenge in agriculture, negatively affecting plant growth and yield [4]. ...
Nitrogen is crucial for plant growth, but deficiency and excess can harm plants. Fertilizers like Diammonium Phosphate (DAP), which releases ammonium (NH4⁺), are common, yet over-application can cause NH4⁺ toxicity, resulting in stunted roots and leaf damage. This study investigated the impact of NH4⁺ toxicity on strawberry growth, yield, and fruit quality to inform better fertilization practices. The experiment was conducted at The Islamia University of Bahawalpur, Pakistan. Five treatments with varying DAP rates (0 g, 4 g, 7 g, 10 g, and 13 g per plant) were applied to strawberry plants in a completely randomized design with four replications. Photosynthetic pigments, hydrogen peroxide (H2O2), malondialdehyde (MDA), electrolyte leakage (EL), and yield parameters were measured. The 4 g DAP treatment yielded the highest chlorophyll-a (0.5775 mg/g FW) and total chlorophyll content (0.705 mg/g FW). However, increasing DAP doses led to a decline in chlorophyll-a, chlorophyll-b, and total chlorophyll content, with the 13 g DAP treatment exhibiting the lowest levels. H2O2 content increased with higher DAP doses, with the 13 g DAP treatment showing the highest value (75 µmol/g FW). Higher DAP doses also increased MDA content and EL, indicating oxidative stress and membrane damage. The 4 g DAP treatment showed minimal changes in H2O2 and MDA content. Moderate DAP levels (4 g per plant) enhanced strawberry growth, yield, and photosynthetic activity, while higher doses caused significant stress, leading to reduced growth and yield. Managing NH4⁺ levels in fertilization is crucial for optimizing strawberry production. Therefore, moderate doses of DAP (ammonium ion) should be used to avoid ammonium toxicity.
... Foliar application of liquid nitrogen fertilizer (for example UAN) is effective and has the benefit of increasing protein content in grain. On the contrary, the application of these fertilizers may present a possible risk due to the leaf burning and possibly yield reduction [112]. Due to the IN, the N fertilizer was applied earlier at the stem elongation in the higher dose. ...
The high input of nitrogen is often required in today's agriculture, especially for the most cultivated crops largely involved in human and animal nutrition, such as winter wheat. Nitrogen is a mobile nutrient in the soil, and the high doses of N are often associated with possible losses through volatilization or leaching. One of the possible options to increase nitrogen use efficiency is the application of fertilizers with inhibitors. The main objective of the presented three-year experiment established under the field conditions at the two experimental sites was to examine the effect of nitrogen-sulphur fertilizer (ammonium nitrate sulphate) with the inhibitors of nitrification (IN) (dicyandiamide and 1,2,4 triazole). In addition to the nitrogen content in two forms, this fertilizer also contains sulphur, which can possibly enhance the utilization of nitrogen due to their well-known synergy. The treatments included in the experiment were: 1. Unfertilized, 2. N technology 3. N + S technology and 4. N + S + IN. The total dose of applied N for every fertilized treatment was 159 kg/ha. Treatments 2 and 3 were fertilized with three split doses of N, treatment 4 was fertilized only two times due to the addition of IN (a higher dose of fertilizer in the second application). The results obtained from the three-year experiment showed a significantly higher yield of grain (8.18 t/ha) after the fertilization with N + S + IN in comparison with N + S (7.67 t/ha) and N (7.61 t/ha), which proved the positive effect of IN on nitrogen use efficiency during the vegetation. The differences between qualitative parameters of wheat grain (hectolitre weight, protein and gluten content) were evaluated as statistically insignificant for each fertilized treatment. This similar result is likely due to the IN application, which provided a continuous nitrogen supply during vegetation comparable to the three split nitrogen applications. Thus, our results showed, that the addition of IN to the higher dose of fertilizer applied earlier in the vegetation can provide comparable results in terms of quality to the technologies based on three split fertilizations. The three-year experiment established at two experimental sites has proved, that the application of ammonium sulphate nitrate fertilizers with IN in a higher dose is a better option to the commonly used nitrogen technology, which was also supported by the economic evaluation and the highest net profit.
... Upon comparing soil applications with two different nitrogen rates, grain yield was not significantly impacted by either UAN or UAN-S. Furthermore, at development stage 30, there were no variations in leaf burning between the two leaf sources (Phillips and Mullins, 2004). When foliar mineral fertilizers are administered during the early stages of grain growth, such as grain and stem elongation, grain mineral density may rise (Arabhanvi and Hulihalli, 2018). ...
Biofortification is a strategy used to alleviate hidden hunger, a condition that affects more than 25% of the world’s population. It involves increasing the concentration of vital vitamins and minerals in basic foods. To increase crop nutrient absorption, a variety of agricultural techniques are used, such as agronomic farming and transgenic farming. Crop type, soil type, and management techniques are some of the variables that affect how successful biofortification is. To successfully alleviate hidden hunger and enhance nutritional security, it is especially crucial to take into account elements like cost-effectiveness, health advantages, and regular mineral intake and one such alternative is agronomic biofortification. Agronomic biofortification can be done through seed priming, soil application and foliar fertilization. The pre-sowing procedure known as “seed priming” improves seed germination and early development, although it may not have a major impact on the micronutrient content in the grains whereas fertilizer used to the soil could not be enough to fulfil the crop’s needs for micronutrients, particularly in soils with low levels of these nutrients and also leading to Nutrient losses from soil via leaching, volatilization, or fixing. Foliar fertilization can tackle all these problems as this method reduces costs and environmental impact by using less fertilizer than soil application, improves nutrient absorption and translocation in grains by providing the right amount at the right time, overcomes soil elements that affect micronutrient availability and movement, such as pH, organic matter, and cation exchange capacity, strengthens plant defenses against abiotic stressors like salt, dehydration, and extreme temperatures without reducing crop quality and production. The article focuses on foliar fertilization which is a more efficient and cost-effective method of biofortifying crops, which may aid in the fight against micronutrient deficiency or hidden hunger.
... The main disadvantage associated with the application of N-fertilizer to leaves is the occurrence of leaf scorching (Sangplung and Rosário 1978;Dick et al. 2016;Ferrari et al. 2021). Leaf scorching is influenced by several factors, including the source, rate, and timing of N-fertilizer application, as well as prevailing weather conditions (Clapp and Parham 1991;Widders 1991;Phillips and Mullins 2004;Fageria et al. 2009;Fernández et al. 2020). In the present study, these factors were controlled, except for the N-rate, as N-urea concentration in the solution, which was the specific factor under evaluation. ...
Foliar N‐fertilization (FNf) has emerged as a promising approach to synchronize plant nitrogen (N) demands and application timing, reducing the N losses to the environment associated with traditional soil‐based fertilization methods. However, limited information exists regarding the effectiveness of FNf in sugarcane. This study aimed to optimize FNf in sugarcane by evaluating N‐fertilizer recovery by the plant (NRP) and assessing potential toxicity effects. Four sugarcane genotypes were subjected to FNf using ¹⁵N‐urea at five nitrogen concentrations. NRP was assessed at five time points for roots, stalk, old leaves, ¹⁵N‐urea‐fertilized leaves (¹⁵NL), and unexpanded leaves (UEL). Leaf scorching, indicating FNf toxicity, was analyzed using morpho‐anatomical and histochemical techniques. The results showed that FNf promoted high NRP, with an average recovery of 62.3%. Surprisingly, the redistribution of ¹⁵N‐urea did not follow the nitrogen uptake rate by sugarcane leaves, with an average of 41.3% of the total‐NRP. The stalk emerged as the primary sink for ¹⁵N‐urea, followed by the UEL. Genotypes differed in the leaf scorching intensity, which increased with higher concentration of ¹⁵N‐urea. Genotypes also differed in the ¹⁵N‐urea uptake rate, down‐regulated by the N content in the ¹⁵NL. These findings emphasize that by carefully choosing the appropriate genotype and nitrogen concentration, FNf can significantly enhance N‐fertilizer uptake, resulting in potential environmental and economic benefits.
... The oxidation of elemental S is governed by microbial activity, which is strongly affected by soil moisture content and soil temperature [22]. Moreover, a plant nutrient has to travel a long path through the plant system (phloem) after its absorption and translocation through the plant roots to reach the leaves and grains, whereas in the foliar application, the nutrients needed by the plant rapidly enter the phloem and reach the target sites [18]. ...
The study was undertaken to evaluate the effect of foliar sulphur (S) nutrition through ammonium thiosulphate (ATS) under conservation management on the growth, photosynthetic efficiency and productivity of rainfed pearl millet in dryland and rainfed conditions of New Delhi in 2021 and 2022 crop years. Pearl millet established under conservation management (ZTCRret) achieved significantly higher crop growth rate (CGR) and relative growth rate (RGR) as a result of improved photosynthesis efficiency in terms of net assimilation rate (NAR) and a higher rate of productive tiller production (RPTP). The productivity of rainfed pearl millet under ZTCRret was improved by 26.6 and 13.5 % during 2021, and by 27.6 and 12.7% over zero tillage (ZTCRrem) and conventional tillage (ConTil), respectively. The application of a recommended dose of S at 30 kg ha-1 resulted in a dramatic improvement in growth indices and photosynthetic efficiency over control and ATS doses up to 0.5%-twice. Foliar application of ATS at 0.5%-once and successively higher doses were found to improve the growth and productivity of pearl millet over S control, however, the dose of ATS at 1.0%-twice could only achieve statistically similar levels of CGR and RGR to the recommended dose of sulphur (RDS) that led to the higher rate of productive tiller production (RPTP) with higher photosynthetic efficiency but in non-significant yield difference. Therefore, the pearl millet established under zero tilled and crop residue retained plots supplemented with foliar feeding of ATS at 1.0% at 20 DAS (4-6 leaves stage) and 50 DAS (flowering stage) can be practiced under rainfed ecologies with a grain and stover yield increase of 19.5% and 13.2%, respectively over the no S application.
... The oxidation of elemental S is governed by microbial activity, which is strongly affected by soil moisture content and soil temperature [22]. Moreover, a plant nutrient has to travel a long path through the plant system (phloem) after its absorption and translocation through the plant roots to reach the leaves and grains, whereas in the foliar application, the nutrients needed by the plant rapidly enter the phloem and reach the target sites [18]. ...
Citation: Ankit; Bana, R.S.; Rana, K.S.; Singh, R.; Godara, S.; Grover, M.; Yadav, A.; Choudhary, A.K.; Singh, T.; Choudahary, M.; et al. No-Tillage
... While these methods not only restrict the potential of sprinkler fertigation to save fertilizer and increase yield, a second irrigation immediately following a fertigation event is difficult to implement when the sprinkler machine has a long running cycle. At present, the identification of leaf burns is mainly based on the appearance of visible foliar scorching, burning, or tipping (Phillips and Mullins 2007), in which the leaves may have been irreversibly damaged (Fageria et al. 2009). Therefore, it is necessary to optimize the fertilizer concentration for sprinkler fertigation by studying the inherent physiological variation in foliar fertigation. ...
The dual role of nutrient uptake by plant roots and leaves is one of the main advantages of sprinkler fertigation, while an improper solution concentration suppresses plant physiology and even causes foliar burns. To explore the suitable solution concentrations of nitrogenous fertilizer, phosphate fertilizer and potassium fertilizer, field experiments were conducted at two sites in the North China Plain during the 2019 and 2021 growing seasons of summer maize. The foliar relative chlorophyll content (SPAD), foliar light energy conversion capacity (Fv/F0) and maximum light energy conversion efficiency (Fv/Fm) prior to and after fertilizer solution spraying were measured and compared. In the experiments, six urea concentrations (0.10 − 3.20%), eight monoammonium phosphate concentrations (0.03 − 4.80%) and seven potassium sulfate concentrations (0.10 − 4.80%) were tested during the jointing stage (V6), flare opening stage (V12), heading stage (VT) and filling stage (R2) of summer maize. The results showed that after spraying fertilizer solution, the spatiotemporal variability in Fv/F0 reached moderate from the weak spatiotemporal variability observed prior to spraying. The SPAD values reached moderate from the weak spatiotemporal variability only after spraying nitrogen fertilizer from V6 to VT and after spraying potassium fertilizer from V12 to R2. All the changes in the index variability suggested a great influence of foliar nutrient absorption on plant physiology. Averaged over 5 days following nutrient spraying during the whole season, the average increments synthesized by SPAD, Fv/F0 and Fv/Fm were 1.60, 1.33, and 1.21 times, and the average reductions were 0.62, 0.78 and 0.62 times, respectively. Depending on the fertilizer type and spraying opportunity, the influence of the fertilizer solution on plant physiology changed greatly. To maximize the relative chlorophyll content and photosynthetic capacity of foliar plants resulting from fertilizer solution spraying, the recommended urea solutions were 0.10 − 0.80%, 0.40%, 0.25 − 0.40% and 0.25 − 0.40% during the V6, V12, VT and R2 stages, respectively. For monoammonium phosphate, the suggested concentrations were 0.06 − 0.15%, 0.06 − 0.15%, 0.03 − 0.40% and 0.03 − 0.80%, respectively. Spraying potassium sulfate at a concentration of 0.10 − 0.40% during the V12 and VT stages would benefit plant growth.
... Based on the obtained data, it can be concluded that maize did not show any nitrogen or other nutrient deficiency (e.g., iron or zinc) in any of the applied treatments, as none of the treatments reduced the relative amount of chlorophyll, compared to the control treatment. Furthermore, the inappropriate time of fertilization or unsuitable weather conditions can cause harmful or negative effects of foliar fertilizer on plants [42]. The application of Zn-containing foliar fertilizer significantly increased the relative chlorophyll content of one, two, and three WAT in this experiment ( Figure 1). ...
The benefit of applying foliar fertilizers is that crops can uptake them faster than soil fertilizers. The aim of this study was to test and valuate the effects of one zinc (Zn) and two amino acids-containing (AS) foliar fertilizers on a fodder corn hybrid’s physiological and biochemical processes. The experiment was conducted in field conditions. The following parameters of a fodder maize hybrid were measured one, two, three, four, five, and six weeks after the treatments (WAT): physiological (relative chlorophyll content and the effectiveness of PSII); biochemical (activities of superoxide dismutase (SOD); ascorbate peroxidase (APX) and guaiacol peroxidase (POD); the concentration of malondialdehyde (MDA); and proline. The yield increased by 10%, 6%, and 10% at Zn, Zn+AS1, and Zn+AS2 treatments. The yield parameters, such as grain/cob and ear weight, were also significantly higher under the applied three treatments relative to the control. The relative chlorophyll content was significantly higher one, two, and four weeks after Zn-treatment, and some changes were also observed when Zn and amino acid-containing fertilizer were applied in combination. The latter sampling did not show any notable changes. In addition, the activity of SOD increased when Zn-containing fertilizer was applied, although the effect of AS-containing fertilizer did not show. There was a correlation between the SOD activity and some of the yield parameters. The increasing SOD activity indicated a higher yield (t/ha) and a higher cob weight.
... Oilseed rape with access to mineral sulphur from the start of the growing period produced a significantly higher seed yield and greater weight of stems, leaves, pods, and roots. The effect obtained from soil application may be explained by the fact that the sulphur compounds contained in the solution applied to the leaves may cause leaf burn, which interferes with photosynthesis and transpiration and negatively affects crop yields [57]. Zhao et al. [58] observed that sulphur was much less effective when applied in autumn than in spring, and that poor utilisation of sulphur was due to losses via leaching. ...
The objective of this study was to assess the yield efficiency of sulphur-enhanced fertilisers, depending on the dose and application method, in a short-lived (three-year) monoculture of winter oilseed rape under the climate and soil conditions of south-eastern Poland. The experiment was carried out between 2010 and 2013 on winter oilseed rape (Brassica napus L. var. napus) of the Orlando variety, fertilised with different sulphur doses—0, 20, 40 or 60 kg S ha⁻¹ applied in different method—soil application sowing, foliar application in the spring, and soil application sowing + foliar application in the spring (combined application). Following the harvest, seed and straw yields and the content of macroelements (N, S, P, K, Ca and Mg) in the seed and straw samples were determined. The harvest indices were also established for each of these elements. The impact of sulphur on winter oilseed rape yield depended significantly on both the dose and the application method. Even at the lowest dose (20 kg·ha⁻¹), sulphur materially increased seed yield, regardless of the application method. With autumn soil application and foliar application, differences between the lowest dose and the higher doses (40 and 60 kg·ha⁻¹) were not significant. However, with combined application, the highest dose (60 kg·ha⁻¹) significantly increased yield compared to the lower doses. In general, all the fertilisation approaches significantly increased the N, P, K, Ca and Mg contents compared to the control sample, but the differences between them were not substantial. Each of the sulphur application approaches decreased the harvest index for sulphur. The foliar application of each of the doses decreased the harvest indices for N, P, K and Ca. The soil application of 20 kg·ha⁻¹, and the mixed application of 40 and 60 kg·ha⁻¹, all increased the harvest indices for P, K and Ca.
... In contrast, a lack of grain yield effect has also been observed in many field studies. Excessive foliar damage may limit grain yield responses when high rates of N are applied under leaves (Phillips and Mullins, 2004). However, two reviews performed by Gooding and Davies (1992) and Fageria et al. (2009) showed that grain yield responses are also closely correlated with foliar application timing. ...
Soybean [Glycine max (L.) Merr.] grain yield is closely associated with the level of optimal nitrogen (N) supply, especially during the reproductive stages. Foliar fertilization with low rates of N have been considered as a strategy for furnishing additional N and enhancing grain yields. Field studies using 15N tracer were conducted over two growing seasons to investigate the impact of foliar N fertilization on grain yield, plant N content, the amount of N derived from fertilizer (NDFF) and N recovery efficiency (NRE). Four foliar N rates (0, 1300, 2600 and 3900 g ha–1) were supplied by two equal split applications at the R1 and R3 stages. Foliar N fertilization of soybean canopies did not affect grain yield, grain N content, shoot N content nor plant N content. Total NDFF was increased from 0.7 to 2.0 kg ha–1 across the N rates. Nonetheless, NRE was unaffected by foliar N fertilization, which averaged 53 %. Soybean plants allocated the same amount of N fertilizer to both grains and shoots. No significant effects of low rate foliar N fertilization were registered on soybean grain yield nor plant N content, despite considerable N fertilizer recovery by plant organs.
... In contrast, a lack of grain yield effect has also been observed in many field studies. Excessive foliar damage may limit grain yield responses when high rates of N are applied under leaves (Phillips and Mullins, 2004). However, two reviews performed by Gooding and Davies (1992) and Fageria et al. (2009) showed that grain yield responses are also closely correlated with foliar application timing. ...
This study checked the nitrogen (N) uptake, fate of the N fertilizer, fertilizer recovery efficiency (FRE) and the residual amount of N fertilizer in the soil via 15N-labelled fertilizer applied to soybean (Glycine max L. Merr.), to explain any differences in the yields. Two soybean field experiments were established in Brazil, one conducted in a tropical (Trop) zone located at Cerrado Biome and the other in a subtropical (Subt) environment. The experimental design was a 2-factor in randomized complete block with four replications. Five doses of N (0, 20, 40, 80 and 120 kg ha−1) were applied at two soybean growth stages (VE and R3). For all treatments, except No-N, 15N-labelled fertilizer was used. The N uptake and the amount of N fertilizer were analysed in the roots, shoots, grains and whole plant, the FRE and yield by soybean, and the residual of fertilizer in the soil. The total N uptake (Nplant) was greater with fertilization at R3 stage compared to the other stage, and N application increased the yield just at this stage and in the Trop condition. The increase in N shoot (not specifically from fertilizer) with the application at R3 appeared to be related to the increased in yield. However, the N from fertilizer found in the plant shoot was about 20% higher when fertilizer was applied at VE compared with R3. Under Subt condition, the FRE averaging 55%. In contrast, the FRE decreased from low to high nitrogen rates (64 to 40%, respectively) when soybean grown under Trop condition. Most N from fertilizer (38%) was found in the grains, followed by the shoot (14.6%) and the root (0.58%). The use of N fertilizer at reproductive growth stages is a better approach to meet soybean N demand through N fertilization. Potential yield gains are more reliable under Trop condition.
... In the literature, some negative effects of foliar fertilizing have been reported [31] like "foliar burn". This can happen if applications were made outside of the proposed time period (phenophase), as well as during unfavorable meteorological conditions. ...
The objective of this study was to evaluate the impact of two foliar fertilizers applied on five maize (Zea mays L.) lines. Fertilizers were applied at different growth stages of maize, during three consecutive years (2010–2012) at the experimental field of the Maize Research Institute “Zemun Polje”, Serbia. Maize growth parameters such as fresh matter, height, leaf area and grain yield were recorded. Foliar fertilizer with amino acids (FAA) was more advantageous to maize plants compared to fertilizer containing phosphorus (FP) as a main component. Applied FAA has shown positive effects by increasing fresh matter, leaf area index, and plant height in all three years. In 2012, due to unfavorable meteorological conditions, grain yield and harvest index were very low, compared to the previous two years, although, positive effects on morphological traits were observed 21 days after treatments (DAT), as well as in the anthesis stage. The best results of 30% of grain yield and harvest index increase were recorded in line L1 in 2010 and 2011. The same line had an increase of more than 40% of fresh matter and leaf area on average for all three years. The positive effects that have been noticed in this research could recommend foliar fertilizing with fertilizer containing N in a form of an amino acids complex.
... Several studies have documented the evidence of N contribution to improved crop yields (Mohammed et al., 2013;Omara, Macnack, Aula, & Raun, 2017;Phillips & Mullins, 2004;Yi, He, Zhang, Yang, & Xiong, 2015). Stewart, Dibb, Johnston, and Smyth (2005) estimated yield increases due to fertilizer N and P to be between 40 and 60%. ...
In many developing countries, crop production is achieved with little or no application of fertilizer N. Understanding grain yield trends as new winter wheat cultivars (Triticum aestivum L.) are released and grown under different N management is important for crop yield improvement. This study evaluated grain yield trends of winter wheat cultivars over time in a crop production system with and without N application. Yield data was obtained from two long‐term experiments; 502 (E502) and 222 (E222) between 1969 and 2018. Results showed a mean annual grain yield increase of 12 and 30 kg ha–1 yr–1 as new cultivars were released and grown under adequate N management in E222 and E502, respectively. However, without N application, yield declined annually by 2.4 kg ha–1 yr–1 in E222 and increased marginally by 0.6 kg ha–1 yr–1 in E502. Nonetheless, the yield increase or decrease was only significant for E502 at 112 kg N ha–1 (r2 = .145; p = .01) and its slope was significantly different from that of control treatment (p = .02). In both experiments, yield was significantly influenced by cultivar and N interaction (p < .01), an indication that yield changed according to the level of N applied. In general, when N was applied, grain yields were high as well. New cultivars released over time improved grain yield with adequate N management.
... Amino acids have already showed the greatest importance in plant nutrition for obtaining of higher yields and quality and shortening of the productive cycle with better dry material [11]. Considerable differences have been reported among fertilizer sources in burning foliage with foliar application of inorganic fertilizers, especially N [12]; however, there are few studies focusing on the plant growth promotion by foliar application of amino acids. Thus, liquid fertilizer produced by amino acids constitutes a potentially important source of nitrogen [13], and foliar application of the novel liquid fertilizer is important for plants in various ecosystems. ...
Leaf surface fertilization with liquid fertilizer produced from amino acids constitutes a potentially important source of nitrogen and is important for plant production. However, few reports have focused on the plant growth promotion by novel liquid fertilizers created by new amino acid resources, let alone the influence on leaf microbiota. In this study, the effects of liquid fertilizer, created by amino acids hydrolyzed from animal hairs with or without the PGPR strain Bacillus amyloliquefaciens SQR9, on crop yield and leaf microbiota were investigated. The results showed that leaves sprayed with amino acid liquid fertilizer (AA) and liquid biological fertilizer (AA9) persistently increased cowpea yields compared to the control amended with chemical fertilizer (CF). Fertilization with amino acid fertilizer showed no significant difference in microbial composition compared with the CF treatment; however, the introduction of functional microbes altered the microbial composition. Pearson correlation analysis, VPA analysis and SEM models all revealed that the amino acids liquid fertilizer application, but not the functional strain or the altered microbiota, performed as the direct driver attributing to yield enhancement. We conclude that leaf fertilization with a novel amino acid liquid fertilizer can greatly enhance the crop yield and that the addition of beneficial microbes may perform the role in further altering the composition of leaf microbiota.
... In contrast, a lack of grain yield effect has also been observed in many field studies. Excessive foliar damage may limit grain yield responses when high rates of N are applied under leaves (Phillips and Mullins, 2004). However, two reviews performed by Gooding and Davies (1992) and Fageria et al. (2009) showed that grain yield responses are also closely correlated with foliar application timing. ...
Soybean [Glycine max (L.) Merr.] grain yield is closely associated with the level of
optimal nitrogen (N) supply, especially during the reproductive stages. Foliar fertilization with low
rates of N have been considered as a strategy for furnishing additional N and enhancing grain
yields. Field studies using 15N tracer were conducted over two growing seasons to investigate
the impact of foliar N fertilization on grain yield, plant N content, the amount of N derived from
fertilizer (NDFF) and N recovery efficiency (NRE). Four foliar N rates (0, 1300, 2600 and 3900 g
ha–1) were supplied by two equal split applications at the R1 and R3 stages. Foliar N fertilization
of soybean canopies did not affect grain yield, grain N content, shoot N content nor plant N
content. Total NDFF was increased from 0.7 to 2.0 kg ha–1 across the N rates. Nonetheless,
NRE was unaffected by foliar N fertilization, which averaged 53 %. Soybean plants allocated the
same amount of N fertilizer to both grains and shoots. No significant effects of low rate foliar N
fertilization were registered on soybean grain yield nor plant N content, despite considerable N
fertilizer recovery by plant organs.
... Los resultados han sido altamente variables, a veces demostrando sustanciales beneficios de las aplicaciones foliares mientras que en otras ocasiones no mostraron efecto (Barraclough y Haynes, 1996;Freeborn et al., 2001;Haq y Mallarino, 2005;Ma et al., 2004;Ma et al., 1998;Mallarino et al., 2001;Schreiner, 2010;Seymour y Brennan, 1995;Tomar et al., 1988) y a veces efectos negativos. Los efectos negativos descritos pueden ser en gran parte explicados por los efectos directos de las sales de los Fertilizantes foliares que causaron quemaduras en las hojas y por ello redujeron el área foliar efectiva y producción de fotosintatos (Barel y Black, 1979a;Bremner, 1995;Fageria et al., 2009;Gooding y Davies, 1992;Haq y Mallarino, 1998;Kaya y Higgs, 2002;Krogmeier et al., 1989;Parker y Boswell, 1980;Phillips y Mullins, 2004). También han sido reportados efectos negativos de aplicaciones foliares de B a flores abiertas (Brown, 2001;Nelson y Meinhardt, 2011); estos pueden ser una consecuencia de que el B aplicado quiebra la direccionalidad del crecimiento del tubo polínico reduciendo así la fertilización efectiva (Dickinson, 1978;Robbertse et al., 1990). ...
La fertilización foliar es una estrategia de nutrición de cultivos ampliamente utilizada y de creciente importancia a nivel mundial. Utilizándolos de manera adecuada, los fertilizantes foliares pueden ser más amigables con el medio ambiente y eficaces que la fertilización al suelo, aunque a veces la respuesta de las plantas a estos tratamientos puede ser variable y muchos de los factores implicados en la eficacia de fertilización foliar se desconocen a día de hoy. El objetivo de éste libro es proporcionar información actualizada y clara sobre las bases científicas relacionadas con las respuestas de las plantas a la fertilizaciónf oliar, haciendo hincapié en los principales factores ambientales, fisiológicos y físico-químicos subyacentes. En los diversos capítulos del libro se discute la información extraída de investigaciones teóricas, ensayos de campo y estudios observacionales, así como sobre el estado de conocimiento de las técnicas de formulación y de aplicación de los fertilizantes foliares.
... On the other side, the levels of crops yield are connected to relations between certain fertiliser compounds. The highest number of investigations were already done for interactions between sulphur and nitrogen [8]. Moreover, positive interaction of sulphur with potassium was also noted in relation to higher plant growth and development. ...
Sulphur plays an important role in metabolism of all living organisms influencing their proper growth and development , and its role in the nitrogen fixation process by nodule bacteria has been already pointed out by many authors. According to the Washington World Institute of Sulphur , there is a real risk of soil sulphur deficiency, which could be a limiting factor of the global food safety. Positive interaction of sulphur with potassium was previously noted in relation to higher plant growth and development. However , there is still lack of investigations concerning on effects of various sulphur and potassium fertilisation on ni-trogenase activity of Fabaceae plants, like broad bean. The aim of the present study was to assess the effects of increasing potassium and sulphur fertilisation in a broad bean culture on the variability in the microbial composition of soil, i.e. total number of bacteria, fungi, actinobacteria, oli-gotrophs and copiotrophs, as well as the enzymatic activity of dehydrogenases, acid phosphatase and nitrogenase of bacteria in symbiosis with the broad bean. Potassium fertilisation increased the number of soil microorganisms ; however, supplementary sulphur fertilisation did not promote development of microorganisms. Applied fertilisation resulted in increasing enzymatic activity of de-hydrogenases, while that of acid phosphatase was lower, when potassium fertilisation was applied at 80 and 160 kg ha-1 and sulphur fertilisation at 25 and 50 kg·ha-1. An enhance in nitrogenase activity was observed at increasing levels of sulphur fertilisation and the absence of potassium fertilisation, as well as under the opposite ferti-lisation scheme whereas potassium fertilisation with higher sulphur doses caused reduction of nitrogenase activity.
... The results have been highly variable, at times demonstrating substantial benefit from foliar applications while on other occasions showing no effect (Barraclough and Haynes, 1996;Freeborn et al., 2001;Haq and Mallarino, 2005;Ma et al., 2004;Ma et al., 1998;Mallarino et al., 2001;Schreiner, 2010;Seymour and Brennan, 1995;Tomar et al., 1988) and sometimes negative effects. The reported negative effects of foliar applications can largely be explained by the direct effects of the foliar salts causing leaf burn thus reducing effective leaf area and photosynthate production (Barel and Black, 1979a;Bremner, 1995;Fageria et al., 2009;Gooding and Davies, 1992;Haq and Mallarino, 1998;Kaya and Higgs, 2002;Krogmeier et al., 1989;Parker and Boswell, 1980;Phillips and Mullins, 2004). Negative effects of the foliar application of B to open flowers have also been reported (Brown, 2001;Nelson and Meinhardt, 2011) and may be a consequence of the applied B disrupting the directionality of pollen tube growth and reducing effective fertilization (Dickinson, 1978;Robbertse et al., 1990). ...
Foliar fertilization is an important tool for the sustainable and productive management of crops, however, current understanding of the factors that influence the ultimate efficacy of foliar applications remains incomplete. Here we provide provide an integrated analysis of the principles, both physico-chemical and biological, known to influence foliar absorption and utilization by the plant, and review the available laboratory and field experimental results to provide insights into the factors that ultimately determine the efficacy of foliar applications. Advancement in this field will require a sound understanding of the physical, chemical, biological, and environmental principles that govern the absorption and utilization of foliar applied nutrients.
... The results have been highly variable, at times demonstrating substantial benefit from foliar applications while on other occasions showing no effect (Barraclough and Haynes, 1996;Freeborn et al., 2001;Haq and Mallarino, 2005;Ma et al., 2004;Ma et al., 1998;Mallarino et al., 2001;Schreiner, 2010;Seymour and Brennan, 1995;Tomar et al., 1988) and sometimes negative effects. The reported negative effects of foliar applications can largely be explained by the direct effects of the foliar salts causing leaf burn thus reducing effective leaf area and photosynthate production (Barel and Black, 1979a;Bremner, 1995;Fageria et al., 2009;Gooding and Davies, 1992;Haq and Mallarino, 1998;Kaya and Higgs, 2002;Krogmeier et al., 1989;Parker and Boswell, 1980;Phillips and Mullins, 2004). Negative effects of the foliar application of B to open flowers have also been reported (Brown, 2001;Nelson and Meinhardt, 2011) and may be a consequence of the applied B disrupting the directionality of pollen tube growth and reducing effective fertilization (Dickinson, 1978;Robbertse et al., 1990). ...
... Furthermore, approaches such as localized fertilizer application, ammonia volatilization inhibition, and foliar application of NH 4 + -release fertilizers are often used to improve nitrogen utilization efficiency (NUE). However, this can cause significant, and rapid, accumulation of NH 4 + in tissues, resulting in stunted roots and leaf damage, commonly described as leaf 'scorching', 'burning', or 'tipping' [1,2,[84][85][86]. NH 4 + /NH 3 deposition from the atmosphere can be an important additional nitrogen source for agricultural plants; however, this has exceeded plant demand in many terrestrial and aquatic ecosystems [5][6][7]14]. ...
Ammonium (NH4+) toxicity is a significant ecological and agricultural issue, and an important phenomenon in cell biology. As a result of increasing soil nitrogen input and atmospheric deposition, plants have to deal with unprecedented NH4+ stress from sources below and above ground. This review describes recent advances in elucidating the signaling pathways and in identifying the main physiological targets and genetic loci involved in the effects of NH4+ stress in the roots and shoots of Arabidopsis thaliana. We outline new experimental approaches that are being used to study NH4+ toxicity in Arabidopsis and propose an integrated view of behavior and signaling in response to NH4+ stress in the Arabidopsis system.
... In traditional agriculture, foliar application of nitrogen is a common method to improve nitrogen utilization efficiency. However, this method can often result in visual damage, commonly described as leaf 'scorching', 'burning' or 'tipping' (Poulton et al. 1990;Gooding & Davies 1992;Phillips & Mullins 2004). ...
Deposition of ammonium (NH₄+) from the atmosphere is a substantial environmental problem. While toxicity resulting from root exposure to NH₄+ is well studied, little is known about how shoot-supplied ammonium (SSA) affects root growth. In this study, we show that SSA significantly affects lateral root (LR) development. We show that SSA inhibits lateral root primordium (LRP) emergence, but not LRP initiation, resulting in significantly impaired LR number. We show that the inhibition is independent of abscisic acid (ABA) signalling and sucrose uptake in shoots but relates to the auxin response in roots. Expression analyses of an auxin-responsive reporter, DR5:GUS, and direct assays of auxin transport demonstrated that SSA inhibits root acropetal (rootward) auxin transport while not affecting basipetal (shootward) transport or auxin sensitivity of root cells. Mutant analyses indicated that the auxin influx carrier AUX1, but not the auxin efflux carriers PIN-FORMED (PIN)1 or PIN2, is required for this inhibition of LRP emergence and the observed auxin response. We found that AUX1 expression was modulated by SSA in vascular tissues rather than LR cap cells in roots. Taken together, our results suggest that SSA inhibits LRP emergence in Arabidopsis by interfering with AUX1-dependent auxin transport from shoot to root.
A field experiment on Bt brinjal (var. BARI Bt Begun-2) was carried out to investigate the effect of boron on its flowering, fruit setts and yield at the Soil Science Division, Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur during 2018. The experiment was laid out in a Randomized Complete Block Design with three replications. The experimental treatment comprised four doses of boron (B), viz. 0.0 (control), 50, 100 and 150 ppm B. Boron in the form of boric acid (H3BO3) was applied at full bloom stage and then the other two sprays were given at an interval of 10 days. Results revealed that the yield and yield contributing characters of Bt begun were significantly influenced by foliar application of boron. Plant height (70.4 cm), number of fruits/plant (30.4), length of fruit (13.4 cm), individual fruit weight (79.0 g), fruit yield/9.0 m 2 (2433 g) were found to be maximum with spraying of B @ 100 ppm compared to the other treatments. Spraying of 100 ppm B recorded the highest fruit yield (24.30 t/ha) which was significantly higher than 150 ppm B and control treatment. According to regression equation, the optimum dose of boron concentration was 85 ppm. Quality attributes, viz. TSS (6.23 o Brix), Vitamin C (22.7 mg/100g and b carotene (25.2 ug/100 g) were also found highest at 100 ppm B. The maximum boron uptake both by fruits (0.07 kg/ha) and plants (0.06 kg/ha) was recorded at 100 ppm B. Therefore, it is concluded that 85 ppm boron (500 ppm boric acid) as foliar application along with other soil applied fertilizers @ 116-32-70-13-2 kg/ha of N-P-K-S-Zn can be recommended for higher yield and quality of Bt begun production.
Foliar fertilization is a potential strategy to supplement P requirements when conditions permit. In 2016 and 2017, canola, pea and wheat were grown in a randomized complete block design trial near Pilger, Saskatchewan, Canada, along with a completely randomized design controlled environment experiment that was conducted with the same soil in the winter of 2016. Each crop received a total P application of 20 kg P2O5 ha-1, with varying proportions of the P applied as seed placed monoammonium phosphate (MAP) supplemented with foliar KH2PO4 (0, 25, 50, and 100%) applied prior to anthesis. Under both field and controlled environment conditions, yield response decreased as the proportion of seed placed MAP decreased. The 100% foliar applied P treatment in canola was able to maintain significantly higher yield than the unfertilized control in the absence of seed-placed MAP, indicating some uptake and response. Of the crops evaluated, canola was most responsive to P fertilization. Phytate content ranged from 68 to over 90% of total seed P, with the highest proportions found in wheat grain and with limited effect of foliar P application on phytate content observed. Fertilizer treatment had had little effect on grain Fe content but there appeared to be an inverse relationship between seed-placed MAP and grain Zn concentration that was less evident when P was applied in foliar form. In this study, foliar P application was unable to substitute for seed-placed MAP, and overall had marginal effect on grain yield and P uptake as well as seed nutritional value.
Keywords: yield components, grain yield, content and biological quality of protein, Gluten index, bread-making properties of wheat flour and dough, quality of baked bread. ABSTRACT. Due to several objective reasons, the sulphur (S) deficiency in agricultural crops in Europe came to the fore in the last decades before the turn of the century. This work gives an overview of the Estonian long-year research concerning winter wheat responses on the S fertilization. This study presents a versatile influence of S application-beginning with the influence on the yield formation, grain yield quantity and quality, followed by the one on the biological quality of wheat proteins, and on the bread-making properties of flour and dough, and ending with the one on the quality indices of baked breads. Field experiments were conducted at two locations on calcaric Cambisol and Podzoluvisol. On the background of N100 or 120 kg ha-1 , S was given as granular NS-fertilizers or foliar applied with Sulfur F3000 or with fungicide Thiovit Jet. Flour and dough properties for bread-making were determined by using a farinograph Brabender. The baking tests were carried out in laboratory conditions. The influence of S on the grain yield and quality, and bread-making properties of wheat depended on the year and location. As the average of experiments, the S application significantly increased the grain yield (r = 0.960). The increasing yields were accompanied by decreasing contents of protein and wet gluten. However, due to S application the biological quality of proteins was increasing, because the contents of some essential amino acids were increasing. The significant positive (r = 0.938) effect of the S application on the Gluten index was revealed, which is a good predictor for the baking quality of wheat flour. In addition, some significant positive effects of the S application on the rheological properties of dough and quality indices of baked breads were demonstrated. Thus, the S addition by nitrogen fertilization in parallel with increasing yields improved several bread-making parameters of wheat flour.
Soil fertility depletion is a major limiting factor affecting crop production in Kenya's arid and semi arid lands deficiency and low usage of commercial fertilizers. Amongst unexplored solutions that can mitigate these constraints includes potential role of rhizobia in crop performance conditions. Thus the present study analyzed the effects of drought stress on nodule formation, growth and yield of four legumes (beans, cowpeas, dolichos lablab and green grams) commonly cultivated in Kenya's ASALs county of Kitui. block design with drought stress treatment (DST) induced through withholding total irrigation and well watered treatment (WWT) maintained as a control. demarcated. The four legumes were randomly assigned to the plots and maintained under WWT. One month after planting (MAP), DST was randomly induced by withholding irrigation in two blocks while WWT was maintained in the other two blocks as controls. Upon t experiment, root nodules were carefully harvested from each legume in both DST and WWT. The nodules were then inoculant for specificity assays under gree DST had significantly (p control or plants under WWT indicating the general deleterious impact of water deficit on legume nodulati lessening GYD in legumes. Amongst the legumes, green grams had significantly (P GYD, TND and least WIX, dolichos, lablab and cowpeas exhibited moderate per three traits while beans showed the least TND, GYD and high WIX under DST. Under DST, Green grams had significantly (p was significantly affected by water stress to give with GYD and negatively with wilting (WIX), potentially implying that higher nodulation might have enhanced nitrogen fixation thus higher legume YLD and tolerance to water deficit. Based on observed performance i.e. wilting index, root nodules number per plant and grain yield, green grams was considered drought tolerant and beans drought susceptible, therefore this study recommends adoption and growing of green grams (variety KS
Chociaż wartość technologiczna ziarna pszenicy jest w wy so kim stop niu de ter mi no-wa na przez genotyp, to podlega także wpływom pogody i na wo że nia. Badania naukowe potwierdzają, że główną rolę odgrywa w tym względzie na wo że nie azotem, a w ostatnich latach dodatkowo zwraca się uwagę na działanie siarki na wo zo wej. Ten ostatni składnik staje się w wielu krajach czynnikiem ogra ni cza ją cym plo no wa nie i jakość ziarna pszenicy w efekcie zmniejszenia dopływu siarki w formie ga zo wych zanieczyszczeń atmosfery. Celem podjętych badań była ocena wpływu zróżnicowanego na wo że nia siarką i azotem na plonowanie pszenicy jarej oraz cechy jakościowe mąki i jej parametry wypiekowe. Doświadczenie polowe założono na gle bie kompleksu żytniego bardzo dobrego. Pierw-szym czynnikiem doświadczenia było nawożenie siarką, w którym uwzględniono obiekty bez siarki i równoległe obiekty z dodatkiem 50 kg S·ha-1. Czynnik drugi stanowiło nawożenie azotem, stosowane w obu obiektach siarkowych, zróżnicowane na 6 poziomów: obiekt kontrolny bez azotu, 25, 50, 75, 100 i 125 kg N·ha-1. Pszenicę zbierano w fazie dojrzałości pełnej. Prze pro wa dzo no ocenę wartości przemia-łowej i wy pie ko wej ziarna pszenicy. Stwierdzono, że zastosowana siarka powodowała przyrost plonu ziarna oraz oddziaływała korzystnie na cechy wypiekowe ciasta. Obserwowano w tych próbkach wzrost ogólnej za war to ści białka, poprawę jakości glutenu oraz zwiększenie objętości i porowatości mię ki szu. Na to miast większe dawki azotu wpływały na wzrost plonu, a także poprawę większości cech mąki oraz cech reologicznych ciasta i uzyskanego pieczywa.
Foliar fertilization offers a specific advantage over soil fertilization when plant demand for nutrients exceeds the capacity of the roots to absorb nutrient and when environmental conditions limit the effectiveness or prevent the application of nutrients to the soil. This IFA publication provides readers an up-to date information and clarification on the scientific basis of foliar fertilization and plant responses to it. It describes the ‘state-of- knowledge’ on the mechanisms of uptake by plant leaves of foliar-applied nutrient solutions.
The authors of the book made an integrated analysis of the physical, chemical and biological principles known to influence the absorption and utilization of foliar fertilizers by plants and reviewed the available laboratory and field trials to provide insights into the factors that determine the efficacy of foliar applications. As current understanding of the factors that influence the ultimate efficacy of foliar applications remains incomplete, the authors strive to illustrate the challenges facing this technology as well as the research and development required for its advancement.
http://www.fertilizer.org/ifa/HomePage/LIBRARY/Publication-database.html/Foliar-Fertilization-Scientific-Principles-and-Field-Practices.html
A slide set entitled "Diagnosing Wheat Production Problems" was developed as an educational tool to assist agricultural students and practioners in diagnosing field problems. It addresses weed, insect, fertility, disease, environ-mental, and other problems of hard red winter wheat (Triti-cum aestivum L.) from emergence to crop maturity. The set contains 106 color slides with a written narrative and is divided into three sections: emergence to winter dormancy, green-up to heading, and heading to crop maturity.
Documenting crop senescence rates is often difficult because of the need for frequent sampling during periods of rapid change and the subjective nature of human visual observations. The purpose of this study was to determine the feasibility of using images produced by a digital camera to measure the senescence rate of wheat and to compare the results with changes in greenness determined by two established methods. Measurements were made as part of an experiment to determine the effects of elevated CO2 and limited soil nitrogen on spring wheat (Triticum aestivum L.) at the University of Arizona's Maricopa Agricultural Center, near Phoenix, AZ. 'Greenness' measurements were made during senescence of the crop with a color digital camera, a hand-held radiometer, and a SPAD chlorophyll meter. The green to red (G/R) for each pixel in an image was calculated and the average G/R computed for cropped images from a digital camera representing 1 m2 for each treatment and sample date. The normalized difference vegetation index (NDVI) was calculated from the red and near-infrared canopy reflectances measured with a hand held radiometer. A SPAD reading was obtained from randomly selected flag leaves. All three methods of measuring plant greenness showed similar temporal trends. The relationships between G/R with NDVI and SPAD were linear over most of the range of G/R. However, NDVI was more sensitive at low values than G/R. G/R was more sensitive above G/R values of 1.2 than SPAD because the upper limits of SPAD measurements were constrained by the amount of chlorophyll in the leaf, while G/R responded to both chlorophyll concentration in the leaves as well as the number of leaves present. Color digital imaging appears useful for quantifying the senescence of crop canopies. The cost of color digital cameras is expected to decrease and the quality and convenience of use to improve.
Increasing grain protein in new higher-yielding cereal grains has recently received added attention due to protein premiums paid to farmers. Hard red winter wheat (Triticum aestivum L.) studies were conducted at two locations in Oklahoma in 1997-1998, 1998-1999, and 1999-2000 to evaluate the effects of late-season foliar N applications on grain yield, total grain N, straw yield, and total straw N. Foliar applications of N were made at two different times (pre- and postflowering) using urea ammonium nitrate (UAN) at rates of 0, 11, 22, 34, and 45 kg N ha-1. Ammonium sulfate [(NH4)2SO4] was also applied at a single rate of 22 kg N ha-1 both pre- and postflowering. A significant linear increase in total grain N was observed for postflowering applications using UAN in five of six site-years. In four out of the six site-years, a significant linear increase was observed for preflowering applications of UAN. No consistent increases or decreases from foliar N applications were observed for grain yield, straw yield, or straw N. Over years and locations, UAN applied preflowering and postflowering at 34 kg N ha-1 increased total grain N over that of the check (no foliar N applied) by 2.7 and 2.4 g kg-1, respectively. Late-season foliar N applications before or immediately following flowering may significantly enhance grain N content and, thus, percent protein in winter wheat.
A recently developed system to predict the optimum N fertilizer rate for winter wheat (Triticum aestivum L. emend. Thell) at Zadoks growth stage (GS) 30 is based on the relationship between measured economic optimum N rate at GS 30 and wheat tissue N content measured at GS 30. However, winter wheat often needs an earlier application of spring N to achieve optimum yield. We therefore developed a test to determine which fields need this earlier (GS 25) application, and to predict the optimum N rate with split-application management using the tissue test or as a single spring application. The optimum N rate at GS 25 was measured over 5 yr, both with and without GS 30 N applications. These measured optimum N rates were regressed against a variety of possible predictor variables measured in the same fields. Tiller density at GS 25 was a good predictor of optimum N rate at GS 25 in a split spring application program. Using this relationship along with the GS 30 tissue test to make N recommendations for winter wheat increased estimated profit relative to using the tissue test alone. Soil NO3 measured to 0.9 m depth was the best predictor of optimum N rate at GS 25 when that is to be the only spring N application, and improved estimated profit relative to applying 90 kg N ha⁻¹ at all sites; however, the economic performance of split spring N applications was substantially better than for any single spring applications. The recommendation system developed by integrating these component relationships is powerful and flexible, and provides field-specific N rate recommendations for all spring N applications to winter wheat, regardless of management decisions about splitting spring N applications.
Research supported in part by grants from the USDA-CSRS Water Quality Res. Program and the Virginia Div. of Soil and Water Conservation.
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Sulfur (S) fertilization is expected to increase corn (Zea mays L.) yields in coarse-textured, well-drained, and low organic matter Coastal Plain soils. This increase is expected because of the reduced quantities of S applied to agricultural lands in the form of by-products from fertilizers applied to satisfy other nutrient requirements, increased removal of S from soil with increased crop yields, and increased emphasis on reducing atmospheric pollutants (thus decreasing S additions from atmospheric sources). This study was conducted to determine if corn yields could be increased by S additions to Coastal Plain soils and to determine if extractable soil S or tissue analyses could be employed to predict this response. Ten S fertilization experiments were conducted over a wide range of soils during 1978,1979, and 1980. Results showed that increased corn yields can be expected with S application on soils that are moderately well to well-drained, low in organic matter, and belong to the fine loamy or coarser textured family of soils, and have acid monocalcium phosphate extractable soil SO4-S concentrations ≤ 2.3 mg kg⁻¹ in the surface horizon. When extractable soil S present in the Ap horizon was related to actual yield increases (∆y max) with a refitted Mitscherlich equation, a significant relationship was evident and 62% of the observed variability in relative yield could be explained. Fertilizer applications ranging from 18 to 28 kg S ha⁻¹ were required to achieve 90% of maximum yield. The requirements appeared to be dependent on the method of application (broadcast preplant or split between broadcast and sidedress). When the relationship between total S and N:S ratio in the leaf below and opposite the ear leaf at silking and ∆y max was examined, 67 and 82% of the observed variation in ∆y max could be explained by a refitted Mitscherlich and a linear equation, respectively. From these equations it was estimated that the critical concentration for total S and N:S ratio would be 1.7 g kg⁻¹ and 16, respectively. These data indicate that extractable soil S or tissue analyses could be used to identify fields that might be S deficient.
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Information is lacking on the N uptake pattern of intensively managed soft red winter wheat ( Triticum aesrivum L.) in the mid‐Atlantic region of the United States. Such information would facilitate decision making for N fertilizer management, increase the precision of simulation models used in research, and delineate crop growth stages for use as indicators of plant N needs. Field experiments were conducted in the Atlantic Coastal Plain region of Virginia during the 1981–1982 through 1984–1985 winter wheat growing seasons to describe the winter wheat N uptake pattern and measure responses to N fertilization. The treatments in these experiments consisted of single or split spring N applications at Zadoks growth stages 25 (GS 25) and 30 (GS 30) totaling 0, 90, or 135 kg N/ha. Total dry matter production and total N concentration were measured in the aboveground plant material and in leaves, stems, and heads. These measurements were made shortly after dormancy, at GS 30,45, and 58, and at harvest to assess the effects of the N fertilizer rates and climatic conditions on crop N uptake. Maximum daily N uptake rates were obtained in the period immediately after GS 30, suggesting that this is when the highest efficiency of N fertilizer use could be expected. Crop N uptake at GS 30 also appeared as a potentially good indicator of the plant N requirement. Total amounts of N found in leaves and stems decreased with time during the spring, while spike N increased from the early stages of head development until harvest. Climatic conditions in the different growing seasons affected plant N uptake. Variations in residual soil N and temperatures in early spring probably determined the differences in amounts and patterns of N uptake by whole plants and by the various plant fractions.
No method exists to reliably predict percent vegetation coverage using indirect measures. This study was conducted to evaluate the use of digital image processing techniques applied to digital color, red‐green‐blue (RGB), images of crop canopies to estimate percent vegetation coverage and biomass. Two field experiments with winter wheat (Triticum aestivum L.) “Tonkawa”; were planted in October 1996 and 1997 at Perkins, OK on a Teller sandy loam (Udic Argiustoll) and at Tipton, OK on a Tipton silt loam (Pachic Argiustoll). Plot images from winter wheat canopies were taken using a Kodak DC40 Digital Camera (1995) with an image resolution of 756 × 504 pixels. Spectral irradiance readings were taken from wheat canopies in red (671±6 nm) and near infrared (780±6 nm) wavelengths, and normalized difference vegetation index (NDVI) was calculated. Percent vegetation coverage was estimated using image‐processing routines in Micrografx Picture Publisher® version 7.0. The digital images were converted from 8‐bit RGB tagged image file format (TIFF) files, which were produced by processing the images from the camera with Photo Enhancer®, to binary pseudo‐color images. Percent of pixels corresponding to the vegetation color was then calculated and used as the percent coverage for each plot. Binary pseudo‐color images provided useful estimates of percent vegetation coverage that were highly correlated with wheat canopy NDVI measurements.
Three experiments were conducted in the Coastal Plain region of Virginia on Kenansville loamy sand, Dothan loamy sand, and Pactolus loamy sand soils. These three soils have low monocalcium phosphate-acetic acid extractable SO/sub 4/-S (<3.1 kg/ha) and would be expected to be S deficient with respect to corn (Zea mays L.) Winter wheat response to S application was investigated on the Kenansville and Dothan soils, while the N x S interaction was studies on the Pactolus soil. Yields were not significantly influenced by S application and averaged 5.6 Mg/ha for the Kenansville and 4.3 Mg/ha for the Dothan soils. In the N x S interaction study, yield increased linearly with increased N application, and N and P tissue concentrations were increased with N application. These data indicate that S concentrations of 0.20% and a N/S ratio of 18 in the flag leaf at Feekes growth stage 10 is sufficient for high yields. The absence of S deficiency in these relatively high-yielding experiments on coarse textured soils with a low levels of extractable SO/sub 4/-S may be related to atmospheric accretions during much of the wheat growing season.
A new 15N technique (termed the negative discard method) for measuring recovery of foliar-applied N by crops in the field is described. 15N-labelled fertiliser solution is sprayed on to a small area of crop, using a hand sprayer, while the surrounding area is sprayed with unlabelled N at the same rate. An area considerably larger than that given 15N is harvested with a small-plot combine-harvester, and crop recovery of foliar-applied N is calculated from the 15N enrichment of the resulting sample containing a mixture of labelled and unlabelled material.
The technique was used to measure recovery of N from 15N-labelled urea solution sprayed on to winter wheat (Triticum aestivum L cv Avalon) at six different times from growth stage 39 (3 weeks before anthesis) to growth stage 73 (2 weeks after anthesis). Each treatment of 40 kg N ha−1 was divided into two equal portions, the second being applied 1–2 days after the first, to minimise the risk of leaf damage. The crop had earlier received 210 kg N ha−1, as ‘Nitro-Chalk’, in spring (50 kg ha−1 at growth stage 22 and 160 kg ha−1 at growth stage 31) which was more than sufficient to achieve maximum grain yield. At harvest, 70% of the foliar-applied N given at anthesis (growth stage 65) was recovered in the above-ground crop, including 64 % in grain. The proportion of labelled N recovered in the grain (92% of that in the above-ground crop) was slightly greater than with soil-applied N given earlier in the growing season. Recovery of foliar-applied N was slightly less for the earliest (growth stage 39) and latest (growth stage 73) times of spraying: 64% and 58% in above-ground crop, and 56% and 54% in grain, respectively. All of the foliar applications of 40 kg N ha−1 increased %N in grain to the same extent as an additional 40 kg N ha−1 applied to soil in spring.
It has been suggested that there are several potential benefits of providing nitrogen to cereals via the foliage as urea solution. These include: reduced nitrogen losses through denitrification and leaching compared with nitrogen fertilizer applications to the soil; the ability to provide nitrogen when root activity is impaired e.g., in saline or dry conditions, and uptake late in the season to increase grain nitrogen concentration. Factors that influence the degree of foliar absorption in field conditions have not, however, been clearly defined and losses to the atmosphere and soil can occur. Foliar urea applications may also hinder crop productivity although the explanations for this vary, and include desiccation of leaf cells, aqueous ammonia and urea toxicity, biuret contamination and the disruption of carbohydrate metabolism. It has not yet been determined which one, or combinations, of these mechanisms are most important in field situations. When damage has not been severe, foliar urea applications have increased grain yield, particularly when applied before flag leaf emergence and when nitrogen availability is limiting. Increases in grain nitrogen content are often larger when applications of nitrogen fertilizers to the soil are reduced, and when the urea solution is sprayed either at anthesis or during the following two weeks. It is during this period that foliar urea sprays can be of greater benefit than soil applications with regard to nitrogen utilization by the crop. Increases in wheat grain nitrogen concentration following urea application can improve breadmaking quality. Responses in loaf quality may, however, be variable particularly when increases in grain nitrogen content have been large, and/or when the nitrogen: sulphur ratio in the grain is increased. These circumstances have lead to alterations in the proportions of the different protein fractions which influence breadmaking potential.
To exploit the full potential benefits of foliar urea application to cereals, more needs to be known about the mechanisms, and thus how to prevent losses of nitrogen from the foliage, and to reduce the phytotoxic influences of sprays. More information is also required to exploit the reported effects that urea may have on limiting the development of cereal diseases.
Crop response to sulfur in the Midwest and Northeastern U.S. Sulphur in Agric
- R G Hoeft
Hoeft, R.G. Crop response to sulfur in the Midwest and Northeastern U.S. Sulphur in Agric. 1980, 4, 12–15.
Oklahoma Soil Fertility Handbook
- G V Johnson
- W R Raun
- H Zhang
- J A Hattey
Johnson, G.V.; Raun, W.R.; Zhang, H.; Hattey, J.A. Oklahoma Soil Fertility Handbook, 5th Ed.; Okla. Agric. Exp. Sta.: Stillwater, OK, 2000.
Intensive Soft Red Winter Wheat Production: A Management Guide
- M M Alley
- D E Brann
- E L Stromberg
- E S Hagood
- D A Herbert
- E C Jones
- W K Griffith
Alley, M.M.; Brann, D.E.; Stromberg, E.L.; Hagood, E.S.; Herbert, D.A.; Jones, E.C.; Griffith, W.K. Intensive Soft Red Winter Wheat Production: A Management Guide; Virginia Coop. Ext. Serv.: Blacksburg, VA, 1993; Publ. 424-803.
Sulfur fertilization needed by wheat on coastal plain soils
- C C Mitchell
- G L Mullins
Mitchell, C.C.; Mullins, G.L. Sulfur fertilization needed by wheat on coastal plain soils. Highlights of Agric. Res., Alabama Agric. Exp. Sta. 1990, 37 (4), 8.
Evaluation of the benefit of substituting foliar urea for soil-applied nitrogen for winter wheat
- D S Jenkinson
Jenkinson, D.S. Evaluation of the benefit of substituting foliar urea for soil-applied nitrogen for winter wheat. Aspects Appl. Bio. 1990, 25, 301–308.
s Guide, Release 6.03 Ed.; Statistical Analysis System Institute
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SAS. SAS/STAT User's Guide, Release 6.03 Ed.; Statistical Analysis System Institute: Cary, NC, 1990.
Can foliar application of nitrogen fertiliser to winter wheat reduce nitrate leaching
- P S Kettlewell
- S A Juggins
Kettlewell, P.S.; Juggins, S.A. Can foliar application of nitrogen fertiliser to winter wheat reduce nitrate leaching. Aspects Appl. Bio. 1992, 30, 103–108.
Nitrogen Management for Winter Wheat: Principles and Recommendations; Virginia Coop
- M M Alley
- P C Scharf
- D E Brann
- W E Baethgen
- J L Hammons
Alley, M.M.; Scharf, P.C.; Brann, D.E.; Baethgen, W.E.; Hammons, J.L. Nitrogen Management for Winter Wheat: Principles and Recommendations; Virginia Coop. Ext. Serv.: Blacksburg, VA, 1996; Publ. 424-026.