Cynthia A Grant

• Ph. D.
• Researcher at Agriculture and Agri-Food Canada

Canola yield and quality are important for food, feed, and industrial end-uses. There may be trade-offs between the agronomic and quality aspects of canola production depending on varietal traits and management. The objective of this work was to assess the effects of nitrogen (N), phosphorus (P), and sulfur (S) fertilization on agronomic and qualit...

AimsRapeseed (Brassica napus L.) is an extensively used rotation crop that provides various benefits to the subsequent crops. One of these benefits is the suppression of soilborne pathogens through its release of biocidal metabolites, which, however, can also have detrimental effects on arbuscular mycorrhizal fungi (AMF). Reduction in AMF activity...

Background Cadmium (Cd) levels of food crops can be elevated through management activities and geogenic factors. While emphasis is placed on reducing Cd in phosphorus (P) fertilizers, increasing evidence shows that Cd accumulation in plants is markedly influenced by arbuscular mycorrhizal fungi (AMF). Mycorrhizas are highly effective in reducing sh...

Determining the dynamics of crop nitrogen (N) uptake is essential to optimize N management and increase the sustainability of crop production. The concept of critical N concentration helps to achieve this goal by defining the minimum shoot N concentration required to produce the maximum aerial biomass at a given time during the crop cycle. The obje...

The world acreage of organic crop production systems is increasing, but the soil microbial dynamics in these systems are not fully understood. We studied the composition and functioning of soil microbial communities in 4-year organic or conventional rotations. The organic systems were tilled to control weeds, and N2-fixing legumes or compost suppli...

Cadmium (Cd) is a naturally occurring element present in all soils from both geogenic and anthropogenic sources. The primary risk pathway to humans is exposure through dietary intake in foods and by inhalation through smoking, with the target affected organ being the kidney. In developed countries, Cd intakes by populations are below levels of conc...

Phosphorus (P) fertilizer has played a vital role in increasing the productivity of crop production in the northern Great Plains for approximately 100 years. Throughout this period, agricultural production practices have changed dramatically, while our knowledge of P behavior and beneficial management practices has improved. Some of the more recent...

Canola (Brassica napus) is the primary oilseed crop in western Canada; however, it is often grown on sulfur (S)-deficient soils. Moreover, canola has a high S demand compared to cereals and, therefore, is particularly sensitive to S deficiency. This study examined the growth and nutrient uptake responses of a high-yielding canola hybrid cultivar to...

A major challenge facing China is to meet the increasing food demand of its growing population in the face of decreasing arable land area, while sustaining or improving soil productivity and avoiding adverse environmental impacts from intensive agriculture. This study uses data from China Statistical Yearbooks to analyze trends in regional soil pro...

The objective of this article is to summarize the results of a study conducted over six years at seven rainfed locations on the Canadian Prairies to determine the residual effects of preceding legume crops and past N fertilizer application rates on the economics of subsequent spring wheat and canola. Earn 0.5 CEUs in Crop Management by reading this...

As legume crops fix nitrogen (N) from the atmosphere, there is concern that soil residual N from legumes grown in rotation with malting barley may result in unacceptably high protein and negative effects on quality. However, little research has been conducted to investigate this. Field pea, lentil, faba bean [for seed or as a green manure crop (GM)...

Soil fertility is the quality of a soil that that allows it to provide adequate amounts of nutrients in the proper balance to support plant growth, but without toxic concentrations of any element. It is related to the ability of the soil to support a healthy plant community, whether in a natural or managed ecosystem. Soil fertility involves the com...

Core Ideas Study on the residual effects of preceding crops and past N management on wheat and canola. Initial positive impact of legume preceding crops on net revenue diminished over time. Residual N had positive effects on net revenue, especially at the highest N rate. Annual fertilization based on production capacity of the region gave the best...

A western Canada field study investigated the effects of seeding date and rate on malting barley quality. Seeding date had little effect on quality. Increasing the seeding rate up to 300 seeds m−2 resulted in higher germination and Kolbach indices, lower β-glucan, and better endosperm modification without compromising malt extract.

HIGHLIGHTS Long-term additions of phosphate fertilizers to soil reduced glyphosate sorption. Co-application of phosphate with glyphosate reduced glyphosate sorption. Sorption was the same for analytical grade glyphosate and Roundup Ultra2. Cd impurities in phosphate fertilizers had no impact on glyphosate sorption.

This research examined the impact of field-aged phosphate and cadmium (Cd) concentrations, and fresh phosphate co-applications, on glyphosate sorption by soil. Soil samples were collected in 2013 from research plots that had received, from 2002 to 2009, annual applications of mono ammonium phosphate (MAP) at 20, 40 and 80 kg P ha(-1) and from produ...

Efficient N fertilizer can improve economic returns and reduce environmental risk. This study evaluated effects of fertilizer rate, source, timing and placement combinations on spring wheat ( Triticum aestivum L.) yield and protein concentration under varying environmental conditions created by differing slope position and seeding dates. Grain yiel...

Deficiency of S in soils has become a soil fertility issue worldwide because of a decrease in S deposition from air to soil due to legislation and increased crop removal. Continuous use of high‐analysis nitrogen/phosphorus (NP) fertilizers lacking in S further exacerbates the S deficiency for crop production. Several newly developed granular NP fer...

Energy use efficiency (EUE) is a key concept which may be used to benchmark best practices in cropping systems through comparison of the impacts of both preceding crops (PCs) and agricultural inputs on crop yield. The EUE is a metric to measure how cultural practices, such as N application and rotational crop use, can influence sustainability in a...

Little is known about nitrous oxide (N2O) emission from silage corn (Zea mays L.). Studies have shown that controlled-release N fertilizers have the potential to reduce N2O emissions, compared with conventional N fertilizers. This 2-year field study compared N2O emissions from urea fertilizer and a slow-release polymer-coated urea (CRU) applied to...

A better understanding of the depth distribution of soil mineralizable nitrogen (N) pools is important to improve prediction of net soil N mineralization. However, our understanding of the depth distribution of these N pools under the semi-arid conditions of western Canada is limited. This study examined the depth distribution of soil mineralizable...

Past agronomic practices, particularly cropping sequence and the balance between N applications and crop N removal, will influence soil N supply and crop yield potential. Nitrogen (N) fertilizer applications required to optimize crop yield and quality will be a function of the difference between crop N demand and the amount of N supplied by the soi...

Field studies were conducted at two locations in western Manitoba over three years to evaluate the impact of rate, source, and placement of nitrogen (N) fertilizer on seedling emergence, disease severity, crop yield, and seed quality of flax (Linum usitatissimum L.). Urea, urea ammonium nitrate (UAN), and ammonium nitrate (AN) fertilizers were appl...

Management strategies to reduce N losses to the environment from potato (Solanum tuberosum L.) production while maintaining yields depend on selecting the right N source and rate. A 5‐yr (2008‐2012) field experiment was conducted on an irrigated sandy soil in Quebec, Canada, to examine the effect of N fertilizer source and rate on total (TY) and ma...

Crop responses to increasing P fertilization are oft en variable and poorly related to soil P test. Our objectives were to determine the influence of P fertilizer on the growth and seed yield of canola (Brassica napus L.) and to develop a first approximation of its critical phosphorus concentration (Pc) in shoot biomass. An experiment with four rat...

Only about 25% of barley (Hordeum vulgare L.) is selected for malting annually in western Canada due to quality issues. While nitrogen (N) fertilization can increase yield, it can also impair quality by increasing protein to unacceptable levels. The objective of this study was to determine the responses of relatively new malting barley cultivars (B...

Critical nutrient concentrations are required for assessing the level of crop nutrition. Our objectives were to validate an existing model of critical phosphorus concentration (Pc = 0.94 + 0.107N) in the shoot biomass (SB) of wheat (Triticum aestivum L.) and to assess the alternative approach of expressing Pc as a function of SB rather than shoot N...

Food production is highly dependent on regional yields of crops. Regional differences in grain yields could be due to fertilizer management and climate variability. Here, we analyze trends of grain yields in North China, Northeast China, East China, and Central and Southwest China from 1992 to 2012, using the Chinese statistical yearbooks. We estim...

Root uptake of calcium (Ca) and potassium (K) with depth in soil and through time are of interest not only as fundamental processes of plant physiology but also for the practical application of crop management. For K specifically, depth of band placement for fertilizer should be optimized for crop uptake. Environmentally rare strontium (Sr) and rub...

Optimizing N fertilization is important to improve both maize (Zea mays L.) yield and nitrogen use efficiencies (NUEs). A 3-yr maize field experiment (2008-2010) was conducted to evaluate the response of grain yield, aboveground biomass, plant N concentration, N uptake, and NUEs to fertilizer N rates from 0 to 280 kg N ha-1 at three di erent rain-f...

This chapter examines the impact of technology and input management practices on greenhouse gas (GHG) emissions produced by different cropping systems in western Canada. Like the previous chapter, the management practices being evaluated include combinations of crop rotations, fertilizer management, and tillage systems. Additional attention is give...

Intensive agricultural production systems rely on the planting of high yielding crop varieties and heavy use of external resources and energy inputs. These external inputs include multiple tillage and seeding operations, high rates of fertilizer and pesticide applications, and intensive use of machinery and fossil fuel energy. The intensive use of...

Assessment and monitoring of soil organic matter (SOM) quality are important for determining and developing management practices that will enhance and maintain the productivity of agricultural soils. This requires routine analysis of multiple soil parameters, which can be time-consuming and expensive. Research has suggested that visible near infrar...

High costs of fertilizer in western Canada have generated interest in alternative N sources. Legumes produce N through fixation, and may increase soil residual and mineralizable N, thus reducing the need for fertilizer N in subsequent crops. Hybrid canola (Brassica napus L.) has a high N requirement for optimum yield, but knowledge of rotational ef...

The rising cost of N in western Canada has created interest in alternative sources of N fertilizer. Legumes have the ability to fix N supply for subsequent crops, but knowledge of the effects of legumes on subsequent canola or barley is limited. A multi-location study was conducted from 2009 to 2011 in western Canada to evaluate the economic effect...

Long-term effects of fresh (FM) versus composted (CM) beef manure application to barley (Hordeum vulgare L.) on potentially mineralizable nitrogen (N 0 ), and mineralizable nitrogen (N) pools, were evaluated in a clay loam soil in southern Alberta, Canada. A suite of laboratory-based indices were evaluated for prediction of soil N supply. The treat...

Field studies were conducted at two locations over 3 yr to evaluate the effect of surface placement of urea ammonium nitrate (UAN) and urea fertilizers, with and without the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) on straw and grain yield of hard red spring wheat (Triticum aestivum L.) grown under reduced tillage management. Amm...

Background and aims Limited information is available on how cadmium (Cd) applied in phosphate fertilizer interacts with soil and environmental conditions over time to affect crop Cd concentrations. Methods Field studies from 2002 to 2009 at seven locations evaluated the cumulative effects of P fertilizer rate and Cd concentration on seed Cd concen...

Accurate estimation of potential nitrogen (N) availability from preceding crops is essential to improve N fertilizer management in agricultural soils. Labile organic N fractions such as microbial biomass N (MBN), water-extractable organic N (WEON), particulate and light fraction organic matter N (POMN, LFOMN) are sensitive to management-induced cha...

A field study was conducted at eight sites in western Canada to determine the influence of agronomic inputs on fatty acid profiles and biodiesel quality of canola. Protein and chlorophyll concentration and fatty acid profiles were determined from seed samples at all sites. Oil was extracted from canola seed samples from three sites, converted to bi...

To evaluate the use of controlled-release urea (CRU) as a beneficial management practice for nitrogen management of wheat, barley, and canola, a multi-location study was conducted from 2004 to 2006 in a range of agro-environments across western Canada. The objective was to evaluate the relative economic performance of CRU and non-coated urea (NCU)...

Seasonal changes in both environmental conditions and substrate quality and quantity determine the soil N supply to plants. The objective of this study was to evaluate seasonal changes in the quantity and quality of soil mineral N (SMN) and mineralizable N pools under a growing potato (Solanum tuberosum L.) crop that was preceded by three crop spec...

Accurate knowledge of the nitrogen (N), phosphorus (P), and potassium (K) requirements for rice (Oryza sativa L.) in China is essential to quantitatively estimate optimal fertilizer application regimes to maximize crop yield and increase nutrient use efficiency. On-farm experiments were collected in China's major rice-producing regions from 2000 to...

Tillage systems are known to influence the quantity and quality of soil organic C (SOC); however, it is unclear if tillage also changes the soil catabolic capacity (the ability to decompose C substrates). This study compared soils from two contrasting tillage systems, no-till (NT) vs. conventional tillage (CT), with respect to their ability to cata...

This project was designed to provide information about the efficiency of nitrogen (N) management practices for western Canadian winter wheat producers. Three factors were included in Experiment 1: 1) urea type (urea, urea+urease inhibitor -‘Agrotain’; urea+urease and denitrification inhibitor – ‘SuperU’, polymer-coated urea – ‘ESN’, and urea ammoni...

Sustainable crop production intensification should be the first strategic objective of innovative agronomic research for the next 40 years. A range of options exist (often very location specific) for farming practices, approaches and technologies that ensure sustainability, while at the same time improving crop production. The main challenge is to...

Crop management tools have been shown to affect barley kernel size and grain protein content, but the direct effect on malt quality is not well understood. The present study investigated the effect of seeding rate, nitrogen fertilisation and cultivar on malt quality. Higher seeding rates produced barley with less grain protein and smaller, more uni...

A 3-year field study was conducted in southwestern Manitoba, Canada, to evaluate the effect of nitrogen (N) fertilizer management and seeding date on end-use quality of wheat, in terms of protein concentration, milling and baking characteristics and grain Fe and Zn concentrations. In each year, experiments were established on two different sites re...

The objective of this study was to evaluate the impact of agronomic practices on net return (NR) risk for malting barley (Hordeum vulgare L.) production. This study used data from two field experiments conducted from 2005 to 2008 at eight rainfed locations in western Canada. The first part of this study included 30 production strategies of barley t...

Georgallas, A., Dessureault-Rompre, J., Zebarth, B. J., Burton, D. L., Drury, C. F. and Grant, C. A. 2012. Modification of the biophysical water function to predict the change in soil mineral nitrogen concentration resulting from concurrent mineralization and denitrification. Can. J. Soil Sci. 92: 695-710. Uncertainty in soil N supply is an importa...

The benefits of no till (NT) management in the short to medium terms need to be examined over decades of continuous cropping. Our objectives were to (i) assess the long term effects of tillage practices (no-till (NT) and mouldboard plough [MP]) and biennial P × N fertilizer rates applied to the maize phase of a two-year maize–soybean rotation on gr...

A 3-yr study was conducted to determine the effectiveness of N fertilizer application times (at planting vs. sidedress) and N fertilizer source (regular urea vs. coated urea) on N2O emissions and corn (Zea mays L.) grain yields from soil under conventional tillage (CT), zone tillage (ZT), or no-tillage (NT) in southwestern Ontario. On average, 4.19...

This study evaluated different strategies for use of a simple first-order kinetic model (N-min = N-0[1- e(-kt)] where N-0 is potentially mineralizable nitrogen and k is the mineralization rate constant) to predict growing season soil nitrogen supply (SNS) in potato (Solanum tuberosum L.) fields under cool humid climatic conditions. All strategies c...

Assessment of the soil N supply capacity is essential to optimize N fertilizer use. The soil N supply capacity of 102 soil samples (0-15 cm) from 25 sites collected from 2004 to 2007 across four Canadian provinces was evaluated by comparing a group of chemical N availability indices with soil mineralizable N pools and a field-based measure of soil...

Zinc (Zn) deficiency is a widely occurring constraint for rice production and for human nutrition. Scarcity of water is leading to a shift from flooded to aerobic rice production, which can have an impact on Zn deficiency in rice. Zinc bioavailability is a function of both soil and plant factors that can be altered by water management, particularly...

Field experiments were conducted at two locations in Manitoba, Canada, to determine the effect of crop rotation, phosphorus (P) fertilization and tillage on grain yield and grain concentrations of Cd and Zn in durum wheat (Triticum durum L.). Compared to conventional tillage (CT), reduced tillage (RT) management decreased grain Cd and increased gra...

Canola or rapeseed (Brassica sp. L.) is a major oilseed, being grown on more than 31 million hectares worldwide. Rapeseed has a high concentration of S in its tissue and seed and a particularly high demand for S relative to its yield potential. Therefore, effective S management is an important part of rapeseed production. Sulfur deficiencies are be...

Barley (Hordeum vulgare L.) growers in western Canada often have difficulty achieving malting grade. This is usually due to unfavourable climatic conditions, but sub-optimal agronomic practices may also be a factor. Field experiments were conducted in 2006, 2007 and 2008 at eight locations in western Canada (24 site-years) to evaluate the effects o...

Relatively high prices and increasing demand for canola (Brassica napus L.) have prompted growers to produce more canola on more cropland. Here we determine if canola seed yield and oil concentration can be increased over current levels with high levels of crop inputs. From 2008 to 2010, direct-seeded experiments involving two seeding rates (75 vs....

Controlled release urea (CRU) has been shown to improve nitrogen fertilizer use efficiency in a number of production systems. However, the effectiveness of CRU will be strongly affected by the environmental conditions of the region. Research trials were conducted at five locations across four major ecoregions spanning 1600 km across the Northern Gr...

Gagnon, B., Ziadi, N. and Grant, C. 2012. Urea fertilizer forms affect grain corn yield and nitrogen use efficiency. Can. J. Soil Sci. 92: 341-351. Controlled-release urea may be a good management strategy to increase the efficiency of N fertilizers. In a 3-yr study (2008-2010) conducted on a clay soil near Quebec City, Canada, we compared the effe...

Cereal crops usually take up less than 50% of the N fertilizer applied. We hypothesized that, depending on application rate, the inorganic N in the soil could affect soil organisms. We investigated the effect of N applied to barley (Hordeum vulgare L.) at soil-test recommended rates (50–80 kg ha−1) in 2004–2006 in a Black Chernozem, and to corn (Ze...

The arbuscular mycorrhizal (AM) fungal resources present in wheat fields of the Canadian Prairie were explored using 454 pyrosequencing. Of the 33 dominant AM fungal operational taxonomic units (OTUs) found in the 76 wheat fields surveyed at anthesis in 2009, 14 clustered as Funneliformis – Rhizophagus, 16 as Claroideoglomus, and 3 as Diversisporal...

The ability of the soil to supply some of the crop nitrogen (N) requirements via the mineralization of organic matter is of economic and environmental importance to producers and society. Water, or its absence, controls microbial activity in soil and thus rates of net N mineralization. Development of a general relationship between soil water conten...

A growth chamber study was conducted to evaluate the effect of application of phosphate fertilizer on soil solution dynamics of cadmium (Cd) and Cd accumulation in durum wheat (Triticum turgidum L. var. durum). Treatments consisted of three phosphate fertilizer sources containing 3.4, 75.2, and 232mg Cd kg−1 applied at three rates (20, 40 and 80mg...

Effect of arbuscular mycorrhizal (AM) fungus on cadmium (Cd) concentration in flax was investigated in a pot experiment. Flax inoculated with Glomus intraradices and uninoculated controls were grown in a pasteurized soil that received Cd (0, 2.5, and 10 mg kg−1) and phosphorus (P; 10 and 50 mg kg−1) additions. Root colonization was not affected by...

Gao, X. and Grant, C. A. 2011. Interactive effect of N fertilization and tillage management on Zn biofortification in durum wheat (Triticum durum). Can. J. Plant Sci. 91: 951-960. A 3-yr field study was conducted at two locations in southwestern Manitoba, Canada, to determine the interactive effect of application of four sources of N fertilizer and...

A field micro-plot experiment for winter wheat was conducted in an irrigated winter wheat (Triticum aestivum)-summer maize (Zea mays L.) rotation system in Mazhuang, Xinji of Hebei province in the North China Plain, using the 15N isotope method to determine the effects of N application (rates and timing), and irrigation frequency on urea-15N fate,...

A field micro-plot experiment for summer maize was conducted in an irrigated winter wheat (Triticum aestivum)-summer maize (Zea mays L.) rotation system in Mazhuang, Xinji of Hebei province in the North China Plain, using the 15N isotope method to determine the effects of N application (rates and timing) on urea-15N fate, residual N effects and N r...

Urea [(NH(2))(2)CO] applied in the seed row can damage seedlings and affect soil microorganisms. A field study was conducted in five site-years to compare the effects of seed-placed and side-banded N applied to barley (Hordeum vulgare L.) at 0 to 120 kg ha(-1) on rhizosphere and bulk-soil microbial biomass carbon (MBC) and functional diversity (H.)...

Two field experiments were conducted to assess the effectiveness of polymer-coated urea (PCU) vs. conventional urea (urea) in minimizing nitrate accumulation in soil and nitrous oxide (N2O) emission while optimizing available N supply. The trials were located on Dark Gray Luvisols (Typic Cryoboralf) near Beaverlodge, Alberta (2004-2007) and Star Ci...

Thirteen bread wheat (Triticum aestivum L.) and two durum wheat (Triticum turgidum L. var. durum) cultivars were grown over six site-years to identify differences in grain Cd and Zn concentrations, as affected by genotypic variation and soil application of potassium chloride (KCl) fertilizer. Application of KCl fertilizer did not consistently affec...

The malting barley (Hordeum vulgare L.) industry is oft en challenged by the availability of sufficient volume and quality to meet demand. Our objective was to evaluate the effects of agronomic practices on grain uniformity, protein concentration, yield, and yield components. Field experiments were conducted from 2005 to 2008 at eight rain-fed loca...

The effects of two tillage systems, two preceding crops and the use of phosphorus (P) fertilizer on arbuscular mycorrhizal fungi (AMF) colonization, root biomass and root size of flax (Linum usitatissimum L.) were evaluated at two sites in Manitoba, Canada. The Brandon Research Centre Farm site had been historically managed under conventional tilla...

Proper N management is essential to prevent N losses and ensure high potato (Solanum tuberosum L.) yield and quality. Controlled-release urea (CRU) could increase nitrogen use efficiency (NUE) by matching the release of N with potato N uptake. This 3-yr study conducted in Québec, Canada, compared four treatments, namely an unfertilized control (0 N...

Field studies were conducted over three years on a clay loam (CL) and fine sandy loam (FSL) soil on the eastern Canadian prairies to evaluate the impact of urea and urea ammonium nitrate (UAN), with or without the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT), placed near the seed-row in a one-pass seeding and fertilizing operation on...

This study evaluated different strategies for use of a simple first-order kinetic model (N-min = N-0 [1-e(-kt)] where N-0 is potentially mineralizable N and k is the mineralization rate constant) to predict growing season soil N supply (SNS) in potato (Solanum tuberosum L.) fields under cool humid climatic conditions. Direct application of the kine...

Livestock manure is an important source of N for forage grass production. The long-term effects of semisolid beef manure application to forage grass on potentially mineralizable N (N-0), mineralizable N pools, and field estimates of soil N supply were evaluated in dike-land (heavy textured, poorly drained) and upland (medium-textured) soils in Nova...

Sulfur is an essential element required for normal plant growth, a fact that has been recognized since 1860 (Alway, 1940). It is considered a secondary macronutrient, following the primary macronutrients nitrogen, phosphorus, and potassium, but is needed by plants at levels comparable to P. Sulfur deficiency will impair basic plant metabolic functi...

Phosphorus fertilizers contain cadmium (Cd) as a contaminant at levels varying from trace amounts to as much as 300mg Cd kg^<-1> of dry product, and therefore represent a major source of Cd input into agricultural systems. Cd will accumulate in soils if the amount of Cd introduced through fertilizer application exceeds that removed by crop harvest...

Cadmium concentration in durum (Triticum durum L.) grain may be influenced by fertilizer management. A three year field study was conducted at two locations in southwestern Manitoba, Canada, to determine the effect of source, timing and placement of N fertilizer on grain Cd concentration of durum wheat under reduced-tillage (RT) and conventional-ti...

Field studies were conducted over 4years at two locations in Manitoba, Canada to evaluate effects of preceding crop, tillage and phosphorus (P) fertilization on Cd and Zn concentration in oilseed flax (linseed—Linum usitatissimum L.). Canola (Brassica napus L.) and spring wheat (Triticum aestivum L.) were grown under conventional and reduced tillag...

Accurate prediction of soil nitrogen (N) mineralization in agricultural soils is of major concern because uncertainty in making fertilizer N recommendations can lead to economic losses and environmental pollution. This study examined the suitability of three temperature functions (Q10, Arrhenius, Logistic) as predictors of the temperature dependenc...