Article

Influence of Low‐Disturbance Fall Liquid Dairy Manure Application on Corn Silage Yield, Soil Nitrate, and Rye Cover Crop Growth

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Abstract

Tillage incorporation of manure can mitigate nutrient loss but increases erosion potential and damages cover crops. More information on the impacts of low disturbance manure application (LDMA) on corn yield, cover crop establishment, and soil properties is needed to better predict manure management practice trade‐offs. Here, corn silage (Zea mays L.) yield, winter rye (Secale cereale L.) establishment, and soil nitrate concentrations were compared for a range of LDMA methods, broadcast incorporation, broadcast/disk, fertilizer N (spring applied at 67, 134, and 202 kg N ha−1), and a no manure control at the University of Wisconsin's Marshfield Agricultural Research Station from 2012 to 2015. Compared to the control, manure and fertilizer N treatments increased corn yield by an average of 1.1‐ to 1.6‐fold and 1.4‐ to 1.6‐fold, respectively. Of the LDMA treatments (sweep‐, strip till‐, and coulter‐injection; aerator/band, broadcast), corn yield was greatest for sweep inject which did not differ from the high N fertilizer rate (P<.0001). Corn yield averaged across LDMA treatments did not differ from the 134 or 202 kg N ha−1 yields. Compared to disking, LDMA maintained more crop residue (P<.0001) with levels comparable to the control. Soil nitrate‐N at 0–30 and 30–60 cm depths was influenced by LDMA and fertilizer N, however leaching to 60–90 cm was comparable among treatments. Results indicate LDMA with injection conserved more N, caused less damage to winter rye, and had similar yields to fertilizer N treatments with improved soil aggregate stability and higher total carbon content. This article is protected by copyright. All rights reserved

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... With less volatilization more N remained in the soil following the injected treatments, which led to a small increase in leaching loss. Field studies have also reported that manure injection increased soil nitrogen concentration at various depths compared to surface broadcast manure that was not incorporated with cereal rye in fall in central Pennsylvania (Milliron et al., 2019) and Wisconsin (Sherman et al., 2020); and into a semiarid perennial grassland in Alberta, Canada (Bork et al., 2013). In our simulation study, the resulting soil N leaching loss was slightly reduced when the fall manure application on rye cropland was delayed one month. ...
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CONTEXT: Strategies are needed to reduce the environmental impacts of dairy farms, and these may become more important as our climate continues to change. Double cropping small grain and corn silages provides a strategy that can benefit dairy farms in the northeastern U.S. as they adapt to a longer growing season. Subsurface application of manure may also reduce nitrogen (N) and phosphorus (P) losses as the region faces warmer temperatures and greater precipitation. OBJECTIVE: Evaluate whole-farm production, environmental and economic impacts of adopting these strategies on a representative dairy farm in central Pennsylvania under recent historical and projected midcentury climate. METHODS: Farm management strategies were simulated using the Integrated Farm System Model to determine effects on crop yields, feed production, volatile, leaching and denitrification losses of N, sediment erosion, sediment-bound and soluble losses of P, farm-gate life cycle greenhouse gas emissions, fossil energy use, and production costs. RESULTS AND CONCLUSIONS: Double cropping increased and stabilized feed production by providing forage from a winter rye crop with less dependency on the summer crops of corn silage and perennial grasses. Summer crops are susceptible to summer droughts, which are expected to increase in this region due to warmer temperatures and increased evapotranspiration. Double cropping was more beneficial in the midcentury climate due to the projected increase in growing season length. Double cropping and subsurface injection of manure reduced total N losses by 12-18% and total P losses by 16-19%. Double cropping using broadcast manure application had a neutral environmental and economic impact on the farm. Adoption of these strategies provided a feasible adaptation and mitigation approach for future climate by reducing projected increases in soluble P runoff and ammonia emission caused by warmer temperatures and greater precipitation while maintaining and potentially reducing total farm production costs. SIGNIFICANCE: Whole-farm simulation provides a tool for evaluating potential benefits and tradeoffs of novel technologies and strategies as agriculture adapts to changes in climate. Although these results are specific to a dairy farm in central Pennsylvania, they generally apply to dairy farms throughout the Northeast U.S. and climates where similar changes in temperature and precipitation are projected by mid-century. Our analyses suggest that use of a more intensive crop rotation (double cropping winter small grain and corn silage) along with improved manure application technology (subsurface injection) can help mitigate dairy farm environmental impacts now and even more in the future.
... Not unexpectedly, there were large concentration increases (46, 312, and 184% increases for TP, DRP, and NH 4 + -N, respectively) and large loading increases for DRP and NH 4 + -N (376 and 197%); TP load also showed a numerical increase of 39%, but was NS (Tables 3 and 4; Figure 3). Previous studies have also demonstrated the importance of manure incorporation or injection to mitigate runoff N and P in corn and hay forage systems [51,52,64,65]. There was a significant decrease in SS, TN, and NO 3 -N concentration, presumably due to the protective soil mulching effect described above regarding runoff effects, but there were no load decreases, except for NO 3 -N, because of the increase in runoff. ...
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ha2 1 (Sainju and Singh, 1997). In addition, hairy vetch can improve soil and water quality compared with bare Tillage and spring kill date may affect cover crop N accumulation fallow by reducing erosion; NO3 leaching during fall, and subsequent N release to the soil, thereby influencing corn (Zea mays L.) N uptake and yield. We examined the influence of three winter, and spring; and increasing organic matter (Sainju tillage practices (no till (NT), chisel plowing (CP), and moldboard and Singh, 1997). In central Georgia, hairy vetch is well plowing (MP)), two cover crop management systems (hairy vetch adapted, producing tomato (Lycopersicon esculentum (Vicia villosa Roth) vs. winter weeds), and two cover crop kill-corn Mill.) yields similar to fertilizer rates of 90 to 180 kg N planting dates (early (early April cover crop kill and mid to late April ha21 (Sainju et al., 1999, 2000a) and increasing soil or- corn planting) vs. late (mid to late April cover crop kill and late April ganic C and N levels similar to those increased by rye to early May corn planting)) on cover crop N accumulation, soil (Secale cereale L.) and crimson clover (Trifolium incar- inorganic N, and silage corn N uptake and yield. An experiment was
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Whereas non-leguminous cover crops such as cereal rye (Secale cereale) or annual ryegrass (Lolium multiflorium) are capable of reducing nitrogen (N) leaching during wet seasons, leguminous cover crops such as hairy vetch (Vicia villosa) improve soil N fertility for succeeding crops. With mixtures of grasses and legumes as cover crop, the goal of reducing N leaching while increasing soil N availability for crop production could be attainable. This study examined net N mineralization of soil treated with hairy vetch residues mixed with either cereal rye or annual ryegrass and the effect of these mixtures on growth and N uptake by cereal rye. Both cereal rye and annual ryegrass contained low total N, but high water-soluble carbon and carbohydrate, compared with hairy vetch. Decreasing the proportion of hairy vetch in the mixed residues decreased net N mineralization, rye plant growth and N uptake, but increased the crossover time (the time when the amount of net N mineralized in the residue-amended soil equalled that of the non-amended control) required for net N mineralization to occur. When the hairy vetch content was decreased to 40% or lower, net N immobilization in the first week of incubation increased markedly. Residue N was significantly correlated with rye biomass (r=0.81, P<0.01) and N uptake (r=0.83, P<0.001), although the correlation was much higher between residue N and the potential initial N mineralization rate for rye biomass (r=0.93, P<0.001) and N uptake (r=0.99, P<0.001). Judging from the effects of the mixed residues on rye N Concentration and N uptake, the proportion of rye or annual ryegrass when mixed with residues of hairy vetch should not exceed 60% if the residues are to increase N availability. Further study is needed to examine the influence of various mixtures of hairy vetch and rye or annual ryegrass on N leaching in soil.
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A winter rye (Secale cereale L.) cover crop can be seeded after corn (Zea mays L.) silage to mitigate some of the environmental concerns associated with corn silage production. Rye can be managed as a cover crop by chemical termination or harvested for forage. A field study was conducted in Morris, MN in 2008 and 2009 to determine the impact of killed vs. harvested rye cover crops on soil moisture and NO(3)-N, and to monitor the impact of the rye on subsequent corn yield. Corn for silage was seeded either after winter fallow (control), after a rye cover crop terminated 3 to 4 wk before corn planting (killed rye), or after a rye forage crop harvested no more than 2 d before corn planting (harvested rye). Soil moisture after killed rye was similar to the control, but after harvested rye was 16% lower. Available soil NO(3)-N was decreased after both killed rye (35%) and harvested rye (59%) compared to the control. Corn biomass yield after killed rye was similar to the control, but yield following harvested rye was reduced by 4.5 Mg ha(-1). Total forage biomass yield (silage + rye) was similar for all treatments. This work demonstrates that the environmental benefits of a winter rye cover crop can be achieved without impacting corn yield, but the later termination required for rye forage production resulted in soil resource depletion and negatively impacted corn silage yield.
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Three experiments were conducted to examine the influence of slurry application rate, wind speed and applying slurry in narrow bands on ammonia (NH3) volatilization from cattle slurry surface-applied to grassland. The experiments were conducted in the field using a system of small wind tunnels to measure NH3 loss. There was an inverse relationship between slurry application rate and the proportion of NH4+-N volatilized. From slurry applied at 20, 40, 60, 80, 100 and 120 m3 ha-1, the respective proportions of NH4+-N lost by NH3 volatization in 6 days were 60, 56, 49, 40, 44 and 44%. The negative relationship was most pronounced in the first 24 hours after application when 57–77% of the total loss for 6 days occurred. Wind speed had a positive effect on NH3 volatilization, although the effect was small in relation to the total loss; increasing the wind speed from 0.5 to 3.0 m s-1 increased the total 5 day loss by a factor of 0.29. The effect of wind speed was also most pronounced in the first 24 hours when much of the NH3 loss took place. The effect of reducing the surface area of the applied slurry was examined by comparing NH3 volatilization from slurry broadcast across plots with that applied in narrow bands. Although the rate of NH3 volatilization was considerably smaller from the banded application immediately after the slurry was applied, the difference between the treatments progressively narrowed until 2 days after application, after which a higher rate was maintained from the banded slurry. After 5 days the total loss from the banded application was 83% of that from broadcast slurry.
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The influence of tillage on net nitrogen mineralization out of sod for two toposequences was estimated by several different methods. A field procedure utilizing small rain shelters to prevent leaching was employed to measure N mineralized in no-tillage (NT) and plowed (CT) treatments for six soils. Potentially mineralizable N and autoclavable N were also determined. An intact soil core procedure was developed to measure N mineralization. With the field procedure, mineralized N was generally greater in the well-drained soils but decreased with decreasing drainage. There was a highly significant interaction between soil type and tillage with greater amounts of N mineralized in the plowed well-drained soils but less in the poorly drained soils when compared to the corresponding no-tillage treatment. The standard laboratory estimates were able to predict differences between soils but did not predict the tillage effect. The development of a laboratory intact core procedure allowed for simulation of tillage effects and was correlated to the field estimates (r = 0.76). More importantly, the tillage ratios for mineralized N (NT:CT), which varied from 1.38 to 0.43, were reasonably correlated (r = 0.73) between the field and intact core procedures. Key words: Mineralized N methods, no-tillage, moldboard plow tillage, intact cores
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This study examined the effects of bare fallow, stubble mulch fallow, and no-till fallow management on aggregate size distribution and organic C and N contents. Mineral-associated organic matter was isolated by dispersing in sodium hexametaphosphate and removing the sand and particulate organic matter (POM) by passing through a 53-μm sieve. A large proportion of the total soil dry weight (50-60%) was isolated in the 250-2000 μm aggregate size class. The native grassland soil was more stable than the cultivated soils when slaked, and the no-till was more stable than the stubble mulch and bare fallow soil when slaked. The data reported relates the loss of structural stability from cultivation to losses of organic C and N from the POM fraction. -from Authors
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There is a need for improved soil and water conservation in the corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation common to the upper Midwest, and an appropriate cover crop may fulfill this need. A corn-soybean rotation that included a rye (Secale cereale L.) cover crop was studied at two Minnesota locations in 2002 and 2003 to evaluate rye management method and timing for no-till soybean production. Fall-planted rye following corn harvest at Waseca and Rosemount was managed the next spring by: (i) mowing once, (ii) mowing twice, (iii) applying glyphosate herbicide once, (iv) applying herbicide twice, and (v) mowing once followed by applying herbicide, with four mow dates beginning 1 May separated by approximately 1 wk. Rye regrowth after mowing but before stem elongation in early to mid-May was similar to that of uncut rye but decreased dramatically when mowed at anthesis in early June. At Rosemount, low weed populations and the presence of the rye cover crop, when properly managed, had only a minimal affect on soybean yield, resulting in the one-pass mowing system being equally profitable as the no-rye two-pass herbicide system. At Waseca, where weed pressure was high, the rye cover crop treatments without subsequent herbicide application as well as the early one-pass herbicide applications did not provide adequate control, making these systems less profitable. Our research indicated soybean yields following a rye cover crop were often comparable to yields where no rye cover crop was grown, but economic returns were usually reduced.
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Removing cover crop top growth in the spring for forage or to prevent incorporation problems is one management option. The effects of this residue management on soil quality and productivity need to be determined. This study, conducted from 1994 to 1998 at Puyallup, WA, determined effects of various winter cover crops and residue management on soil N availability, soil C and N, and corn (Zea mays L.) yield. Included in the study were monocultures of rye (Secale cereale L.), ryegrass (Lolium multiflorum Lam), and vetch (Vicia villosa Roth subsp, villosa) and biculture of vetch and rye or ryegrass. Each year, the cover crops were seeded in the fall and incorporated into, or removed from, the soil in the spring. Average top-growth biomass was higher for the bicultures than for the monocultures. Total N accumulation was generally greatest under vetch, followed by the bicultures, and lowest for the monocultured rye or ryegrass. Whereas removing top growth of monocultured vetch or bicultures depressed presidedress soil NO3-N (Ni), the effect was generally not found for monocultured rye or ryegrass. Corn yields were affected by amounts of Ni and N fertilizer applied (r2 > 0.789), irrespective of cover crop species and residue management. Removing top growth of the cover crops limited residue C input and reduced soil organic C and N after 5 yr. Soil organic C and N accumulation, as well as increasing soil C sequestration to reduce CO2 release into atmosphere, should be considered when deciding which residue management option to choose.
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The use of a winter rye (Secale cereale L.) corn (Zea mays L.) doable cropping sequence in combination with appropriate tillage practices could increase biomass production and reduce soil erosion potential in southern Ontario. A 3-yr study (1982–1984) was conducted at two locations to determine the potential of this sequence for double cropping, and to evaluate spring tillage systems and management of the rye residue on subsequent productivity of corn. Winter rye was planted in early October after corn silage harvest, and either chemically killed or harvested as silage in the spring before corn planting. Rye treatments consisted of no rye, rye harvested in the spring and rye residue left on the plots. Spring cultivation treatments were no-till, tandem discing, and mold board plowing followed by secondary tillage. The use of a winter rye cover crop delayed corn development and reduced corn biomass yield by 11% at the Elora location and by 17% at the Woodstock location. The adverse effect of the rye crop was more pronounced under no-till than where the soil was tilled. Removal or retention of the rye residue had no consistent effect on the subsequent corn crop. An allelopathic effect resulting from the rye crop may be one plausible explanation for the reduction in corn yield. Total biomass yield (rye + corn) was increased relative to corn alone, if the soil was cultivated. Therefore, a winter rye-corn sequence may still be of interest, despite a reduction in corn yield, especially if advantages such as total biomass production and the potential for decreased soil erosion during fall and winter are considered. Research supported by Agriculture Canada (ERDAF). Please view the pdf by using the Full Text (PDF) link under 'View' to the left. Copyright © . .
Article
Studies assessing the effects of tillage and N fertilizer treatments on relationships between different N pools in soil can provide information concerning the influence of such treatments on the distribution of N in agricultural soils. To assess the effects of treatments on relationships between total-N, biomass-N and active-N in soil, these N pools were measured in samples of soil collected at different depths (0–2.5, 2.5–7.5 and 7.5–15 cm) from long-term field experiments located in two geographic regions (piedmont and coastal plain) and containing plots under annual treatments of plow-or no-tillage and 0 or 135 kg ha−1 of fertilizer N. Results showed that whereas geographic location, N fertilization and depth generally had little influence on the slopes of regression lines describing the linear relationships between total-N, biomass-N and active-N, tillage had a marked influence on these slopes. Such results indicated that tillage may substantially influence the distribution of N among different pools within agricultural soils. The overall results for linear regressions indicated that the active-N pool, as measured by an isotope-dilution method, was very closely related (r = 0.96) to the biomass-N pool, as measured by a fumigation-incubation method, but that measurements for the active-N pool were approximately twice those for the biomass-N pool. These observations suggested that such methods may measure a common pool of soil N, but place substantially different bounds on the size of this N pool.
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This chapter discusses the fate of nitrogen applied to soils. Nitrogen in the soil may undergo several changes. The chief channel of nitrogen loss in normal agricultural practice is probably leaching that usually occurs chiefly in the fall and spring months. The major gaseous loss is believed to be molecular nitrogen formed from nitrates and nitrites, by biological denitrification. There is also some evidence for slow and continuing losses of nitrogen to the air in the finer-textured soils, as a result of denitrification in soil aggregates or anaerobic pockets. Heavy applications of urea or ammonia may lead to nitrite formation. This inhibits nitrate formation and cause large losses of nitrogen, chiefly as molecular nitrogen in slightly acid soils. The mechanism of loss is still undetermined, but the gas is believed to result from the interaction of nitrous acid, with undetermined soil constituents. Apparently, the nitrous acid or nitrite is either reduced chemically to nitrogen gas or it may react, with NH2 groups in the soil organic matter, according to a Van Slyke type of reaction. Two methods can be used for determining nitrogen recovery. The most accurate method for determining the recovery of added nitrogen is, by 15N assay, provided the nitrogen remaining in the soil is determined. Nitrogen recovery can also be determined, by the difference method. This method commonly gives results that agree closely, with those, by the tracer procedure, if a residual crop is also grown, and very low nitrogen rates are avoided.
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Soil NO 3 concentration and soil N-supplying capability (NSC) at soil NO 3 levels below the critical level were not correlated well enough (r 2 =0.34) to use the predicted NSC for adjusting N-fertilizer recommendations. As a result, the best use of this test in Pennsylvania appears to be in identification of nonresponsive sites rather than predicting N-fertilizer rates. Use of this test by farmers in Pennsylvania will help minimize the practice of applying «insurance» N when N contributions from manure and legumes in rotations are uncertain
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Two field experiments were conducted, each over a 3-yr period, to compare the availability of N from liquid cattle manure (LCM) with that from urea and anhydrous ammonia to corn. Two times of application (preplant vs. sidedress) and two methods of application (surface vs. injection) of LCM were compared with respect to corn grain yield and soil NO3− concentration during two periods of the growing season. The availability of LCM N was approximately one-half that of fertilizer N. Injection of LCM either before planting or as a sidedressing between the corn plant rows resulted in LCM N being approximately 60% as available as fertilizer N. Application of LCM to the soil surface, as a side dressing resulted in LCM N being approximately one-third as available as anhydrous ammonia N. The data were discussed and interpreted on the basis that manure N is made up of two principal fractions, "organic" and ammoniacal N. The organic N fraction, consisting of all the N other than ammonia, becomes only partly available ...
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Tillage systems need to be compared over an extended period of time to determine their transitional and long-term impacts on crop growth and soil properties. A 15-yr experiment established in 1976 compared reduced tillage systems with conventional fall moldboard plowing for production of continuous corn (Zea mays L.) on a Maryhill silt loam soil (Typic Hapludalf). Corn plant growth and yield and soil properties were compared for five tillage systems: fall plow (fall mold-board plow + spring secondary tillage), fall chisel plow (fall chisel plow + spring secondary), spring plow, spring plow/secondary (spring plow + secondary), and no-till. No-till consistently resulted in slower plant growth than most or all of the other tillage systems. The fall plow and spring plow/secondary treatments resulted in grain yields averaging 5% more than fall chisel plow, 9% more than spring plow, and 16% more than no-till yields. From 1976 to 1983, no-till yields tended to increase relative to fall plow; from 1988 to 1990, however, no-till yields were much less than fall plow. No-till resulted in the lowest proportion of aggregates < 5 mm in diameter, highest bulk density, and greatest penetrometer resistance. Penetrometer resistance of the spring plow plots increased at a slower rate with depth than the fall chisel plow system. Among soil properties measured, the proportion of aggregates < 5 mm in diameter was most often significantly correlated with yield. Please view the pdf by using the Full Text (PDF) link under 'View' to the left. Copyright © . .
Article
The manures and their average NH4+-N:total N ratios were: liquid poultry manure (LPM), 0.89; liquid dairy cattle manure (LCM), 0.53; and solid beef cattle manure (SBM), 0.09. The manures were applied at rates of 100, 200 and 300 kg total N ha-1. An additional LCM treatment of 600 kg total N ha-1 was included. For comparison with the manures as N sources, urea was applied at rates of 50, 100 and 150 kg N ha-1. Soil NO3- concentrations in mid-June generally increased with the urea, LPM and LCM sources of N at the higher rates of application in the field. Lower soil NO3- concentrations with SBM reflected the lower availability of N. -from Author
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Land application of dairy (Bos taurus) manure has generated concern regarding the downward movement of nutrients and pathogens from the manure through the soil profile into subsurface drainage water and ultimately to surface waters. The objective of this study was to determine the effect of dairy manure and urea applied at equivalent rates of 'available' N on (i) NO3-N, total phosphorus (TP), ortho. P, NH3-N, and Escherichia coli losses to subsurface tile drainage; (ii) corn (Zea mays L.) production; and (iii) changes in soil test phosphorus (STP) and soil test potassium (STK). Liquid dairy manure and urea fertilizer were broadcast applied at equivalent total 'available' N rates ranging from 154 to 224 kg ha-1 yr-1 each fall during 1993-1996. The soil was a poorly drained Webster clay loam (fine loamy, mixed, superactive, Typic Endoaquoll). Nitrate N, TP, and ortho-P concentrations and NO3-N losses in the subsurface drainage water were not different between the two N sources. Total P exceeded the minimum detection limit in 40 and 52% of the drainage samples from the urea and manured plots, respectively, while only 22 and 35% of the samples had detectable levels of ortho-P. Losses of TP and ortho-P were very small and averaged 31 and 10 g ha-1 yr-1, respectively, from the manured plots or <:0.02% of the manure-P applied. Four- year average corn yields were 0.7 Mg ha-1 greater for the urea treatment compared with dairy manure. Soil test P and STK in the top 20 cm were increased 1 mg kg-1 for every 12 kg P ha-1 and 10 kg K ha-1 applied as manure. We conclude that dairy manure, when applied at optimal rates and incorporated immediately, does not lead to greater losses of N and P in subsurface drainage water on this fine-textured soil compared with urea.
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A field study was conducted on an Enosburg fine sandy loam (Mollic Haplaquent) in northwestern Vermont to evaluate the effect of dairy-manure and N-fertilizer application on corn yields and soil profile NO3 in a silage production system. Yields and N uptake were increased by N fertilizer and by manure. Plant uptake of N followed a similar pattern but with somehwat more pronounced effects. Sampling of the 1.5-m soil profile before planting and after harvest showed increases in soil NO3 that were related to the amounts of manure and fertilizer N applied. Some decreases in NO3 were measured from fall to spring sampling times. Application of manure resulted in similar or slightly lower soil profile NO3 than agronomically equivalent rates of fertilizer N. -from Author
Article
and leaching of manure nutrients during winter from forage stands will be less than from bare soil or cover Low-disturbance methods for applying slurry manure on forages crops after harvest of annual crops. are needed that can maximize crop response and minimize loss of The traditional method for spreading liquid manure nutrients to the environment. A new implement [Aerway SSD (subsurface deposition slurry applicator)] that bands manure over aera- on forage crops, surface broadcasting with a splashplate tion-type slots was assessed relative to conventional broadcasting and applicator, is rapid and inexpensive. However, broadsurfacebanding.Thecomparisonwasbasedonimmediateandresidual casting of manure is typically uneven, especially under crop responses to single and multiple applications of dairy slurry by windy conditions (Huther, 1988). Broadcast manure tall fescue (Festuca arundinacea Schreb.) and orchardgrass (Dactylis may also damage grass swards (Christie, 1987; Prins and glomerata L.). Also, ammonia emissions were compared using both Snijders, 1987; Wightman et al., 1997) and contaminate semiopen chamber and micrometeorological (integrated horizontal standing plants with microorganisms that can impede flux)methods. Theaerationslotswithoutmanuregenerallydidnothave silage fermentation (Anderson and Christie, 1995; Stefa significant effect on yield or N uptake. Averaged over all harvests, fens and Lorenz, 1998). Surface-applied manure is also surface banding increased yield and N uptake over broadcasting by prone to runoff into waterways (Uusi-Kamppa and Hei6.9 and 6.8%, respectively. The SSD increased yield and N uptake nonen-Tanski, 2001). Crop response to broadcast appliover surface banding by 4.4 and 7.5%, respectively. The relative effeccation of slurry manure is often inconsistent (Bittman tiveness of the techniques on yield varied among experiments. In the et al., 1999), and this probably discourages farmers from ammonia volatilization trials (micrometeorological method), loss of applied total ammoniacal N in the 2 wk after application ranged from using slurry as a primary nutrient source. Inconsistent 36 to 61% for broadcast manure compared with 17 to 32% for SSD- crop response is largely attributed to volatilization of applied manure. With both micrometeorological and semiopen cham- ammonia,whichisinfluencedbymanureproperties,soil ber, ammonia emissions from applied manure were 46 to 48% lower attributes, and weather conditions (Stevens and Laughwith the SSD than with broadcasting. Emissions from surface-banded lin, 1997; Sommer and Hutchings, 2001). Volatilization manure (chamber method) averaged 33% greater with surface band- of ammonia is reduced by minimizing the surface expoing than with the SSD. The results indicate that the SSD manure sure of manure with the air and improving contact with applicator reduced ammonia loss and increased yield and N uptake the soil (Sommer and Hutchings, 2001). There is more relative to broadcasting and surface-banding techniques. ammonia loss after broadcasting of liquid manure on stubble than on bare soil, particularly if the manure has high dry matter content, because of increased exposure
Article
The effects of liquid dairy cattle (Bos taurus) manure on corn (Zea mays L.) yield and composition were studied in a 4-yr field experiment conducted under a Mediterranean environment. In addi- tion, long-term impact of (8-yr) manure application on soil-available NO3-N, P, and K; organic C; Kjeldahl N; and salinity was investigated. Four treatments were established in plots, previously used for a simi- lar 4-yr experiment with winter wheat (Triticum aestivum L.). Treat- ments were: (i) application of 80 Mg manure ha21 yr21; (ii) single application of the equivalent N-P as inorganic fertilization (260 kg N ha21 yr21 and 57 kg P ha21 yr21); (iii) identical to (ii), but with split N application; and (iv) no fertilization. Corn grain and silage yields, N-P-K plant concentration, and uptake were significantly increased by manure or inorganic fertilizer addition relative to the control. Dur- ing the 4-yr corn experiment, the amounts of available NO3-N in the soil profile of manure plots were higher than control, but similar to both inorganic fertilization treatments. Manure application main- tained the amounts of soil available NO3-N, P, and K at desirable levels, almost each year of the total 8-yr application. However, soil organic C and Kjeldahl N remained unchanged. At the end of the experiment, soil salinity below 30 cm was significantly increased on manure or inorganic fertilizer addition relative to the control, but at levels acceptable for most crops. In conclusion, soil application of liquid dairy cattle manure at a rate equivalent to the recommended inorganic fertilization can enhance corn yield and composition and main- tain soil fertility at desirable levels, without increasing soil salinity at unacceptable levels.
Article
In Sweden, 90% of ammonia (NH3) emissions to the atmosphere originate from agriculture, predominantly from animal manure handling. It is well known that incorporation of manure into soil can reduce NH3 emissions after spreading. However, there is a risk of increased nitrous oxide (N2O) and methane (CH4) emissions caused by bacterial activity and limited oxygen availability under these conditions. A full-scale injector was developed and evaluated in a field experiment on grassland. Cattle slurry was either injected in closed slots 5 cm below ground or band spread on the soil surface above the crop canopy at a rate of 25 t ha−1. In a control treatment, no slurry was applied. During a 5-day period after application, NH3 emissions were measured using an equilibrium concentration method. Gas samples for estimating CH4 and N2O emissions were also collected during 7 weeks following slurry application. Injection in closed slots resulted in no detectable NH3 emissions. After band spreading, however, NH3 emissions corresponded to nearly 40% of the total ammoniacal nitrogen in the applied slurry. The injection of slurry gave rise to a broad peak of N2O emissions during the first 3 weeks after application. In total, for the measuring period, N2O emissions corresponded to 0.75 kg N ha−1. Band spreading resulted in only a very small N2O release of about 0.2 kg N ha−1 during the same period. Except for the first sampling occasion, the soil was predominantly a sink for CH4 in all the treatments. The use of the injector without slurry application reduced grass yield during unfavourable growing conditions. In conclusion, shallow injection in closed slots seems to be a promising technique to reduce negative environmental impacts from NH3 emissions with a limited release of N2O and CH4.
Article
In the United States, millions of hectares of highly erodible cropland have been in the Conservation Reserve Program (CRP) for the past 10 years. Any conversion of CRP land back to maize (Zea mays L.) and soybean (Glycine max L. Merr.) production could require the use of conservation tillage systems, such as NT and CP, to meet federal and state soil erosion control standards. Evaluations of yield response of these conservation tillage systems such as NT and CP, over time are needed to assess the return of this land to crop production. An eight-year study was conducted in southern Illinois on land similar to that being removed from CRP to evaluate the effects of conservation tillage systems on maize and soybean yields and for the maintenance and restoration of soil productivity of previously eroded soils. Soils had been in tall fescue (Festuca arundinacea L.) sod for more than 10 years prior to the study. In 1989, no-till (NT), chisel plow (CP), and moldboard plow (MP) treatments were replicated six times in a Latin Square Design on sloping, moderately well-drained, moderately eroded phase of a Grantsburg soil (Albic Luvisol) (fine-silty, mixed, mesic Typic Fragiudalf). Starting with maize, maize and soybean were grown in alternate years. Surface crop residue levels were higher with the NT system than with the CP and MP systems. Soil temperature at 20 cm was lower (1.1°C) with NT than with the other systems in 1996. Plant-available water was slightly higher with NT and CP systems than with the MP system. In 1995, maize was taller with the NT system than with the MP and CP systems. The MP system plots had higher plant populations in 1995 and 1996, but crop yields were higher with the NT system than with the MP system. The four-year average maize yields were equal (9.81, 9.74, and 9.80 Mg ha−1) for NT, CP, and MP systems, respectively, as a result of a significantly higher yield with the MP system in the first year which offset the higher yields with the NT and the CP systems during the last two years. The four-year average soybean yield with NT (2.90 Mg ha−1) was 15% higher than with the MP (2.55 Mg ha−1) system. Crop yields for eight years (four years maize and four years soybean) appear to show improved long-term productivity of NT compared with that of MP and CP systems.
Article
Reducing ammonia (NH3) emissions through slurry incorporation or other soil management techniques may increase nitrate (NO3) leaching, so quantifying potential losses from these alternative pathways is essential to improving slurry N management. Slurry N losses, as NH3 or NO3 were evaluated over 4 yr in south-central Wisconsin. Slurry (i.e., dairy cow [Bos taurus] manure from a storage pit) was applied each spring at a single rate (-75 m3 ha(-1)) in one of three ways: surface broadcast (SURF), surface broadcast followed by partial incorporation using an aerator implement (AER-INC), and injection (INJ). Ammonia emissions were measured during the 120 h following slurry application using chambers, and NO3 leaching was monitored in drainage lysimeters. Yield and N3 uptake of oat (Avena sativa L.), corn (Zea mays L.), and winter rye (Secale cereale L.) were measured each year, and at trial's end soils were sampled in 15- to 30-cm increments to 90-cm depth. There were significant tradeoffs in slurry N loss among pathways: annual mean NH3-N emission across all treatments was 5.3, 38.3, 12.4, and 21.8 kg ha(-1) and annual mean NO3-N leaching across all treatments was 24.1, 0.9, 16.9, and 7.3 kg ha' during Years 1, 2, 3, and 4, respectively. Slurry N loss amounted to 27.1% of applied N from the SURF treatment (20.5% as NH3-N and 6.6% as NO,-N), 23.3% from AER-INC (12.0% as NH3-N and 11.3% as NO3-N), and 9.19% from INJ (4.4% as NH3-N and 4.7% as NO3-N). Although slurry incorporation decreased slurry N loss, the conserved slurry N did not significantly impact crop yield, crop N uptake or soil properties at trial's end.
Article
Injection of liquid swine manure disturbs surface soil so that runoff from treated lands can transport sediment and nutrients to surface waters. We determined the effect of two manure application methods on P fate in a corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] production system, with and without a winter rye (Secale cereale L.)-oat (Avena sativa L.) cover crop. Treatments included: (i) no manure; (ii) knife injection; and (iii) low-disturbance injection, each with and without the cover crop. Simulated rainfall runoff was analyzed for dissolved reactive P (DRP) and total P (TP). Rainfall was applied 8 d after manure application (early November) and again in May after emergence of the corn crop. Manure application increased soil bioavailable P in the 20- to 30-cm layer following knife injection and in the 5- to 20-cm layer following low-disturbance injection. The low-disturbance system caused less damage to the cover crop, so that P uptake was more than threefold greater. Losses of DRP were greater in both fall and spring following low-disturbance injection; however, application method had no effect on TP loads in runoff in either season. The cover crop reduced fall TP losses from plots with manure applied by either method. In spring, DRP losses were significantly higher from plots with the recently killed cover crop, but TP losses were not affected. Low-disturbance injection of swine manure into a standing cover crop can minimize plant damage and P losses in surface runoff while providing optimum P availability to a subsequent agronomic crop.