Nitrogen Fertilization Of Corn Research Articles

Economic feasibility of optical sensors for variable rate nitrogen fertilization in corn

Economic feasibility of optical sensors for variable rate nitrogen fertilization in corn

Long-term no-till increases soil nitrogen mineralization but does not affect optimal corn nitrogen fertilization practices relative to inversion tillage

No-till management is a proven practice for increasing soil organic matter in many environments. By increasing soil organic matter, no-till may increase soil N mineralization, potentially reducing crop demand for N fertilizer relative to inversion tillage. In this study, we hypothesized that, relative to inversion tillage (moldboard plowing), long-term no-till would: i) increase total N stocks, ii) increase mineralized N during the growing season, iii) increase grain yield and N uptake, and iv) reduce reliance of corn (Zea mays L.) on N fertilizer inputs. We tested these hypotheses in a long-term, continuous corn tillage and fertilizer N rate study located in Lexington, KY. We measured the total soil N and potentially mineralizable N after 48 years, the in situ mineralized N and N uptake during two corn seasons (2018–2019), and the corn grain yield for five seasons (2015–2019). We evaluated the effect of no-till on N fertilizer reliance in two ways – the first was by measuring the agronomic optimum N rate of corn in the two tillage systems, and the second was by measuring the corn yield response to late N fertilization timing in the two tillage systems. We found that the no-till system had 1000 kg N ha−1 greater total soil N stocks in the top 20 cm, mineralized 65 kg ha−1 more N during corn growth, and resulted in 22−71 kg N ha−1 and 780−1800 kg ha−1 greater N uptake and grain yield across N rates, respectively, than the plowed system. The agronomic optimum N rate (AONR) did not differ among tillage treatments, potentially because the no-till treatment yielded more and thus demanded more N. Although corn yield responded to the late N fertilization treatment, the response was similar in both the no-till and plowed treatments. We conclude that long-term no-till increases soil N mineralization and corn yield relative to inversion tillage, with minimal effect on the AONR or optimal timing of N fertilizer application.

When to Use a Single or Split Application of Nitrogen Fertilizer in Corn

One strategy to reduce the risk of N loss is to apply N fertilizer in amounts and at timings that closely match the water and N uptake pattern of corn. This article looks at results from a 49 site‐year study across eight U.S. Midwestern states to provide examples of the influence of soil properties and weather on the effectiveness of split vs. single at‐planting N applications. Earn 0.5 CEUs in Nutrient Management by reading this article and taking the quiz at www.certifiedcropadviser.org/education/classroom/classes/807.

AI Down on the Farm

Agriculture has become an information-intensive industry. In the production of crops and animals, precision agriculture approaches have resulted in the collection of spatially and temporally dense datasets by farmers and agricultural researchers. These big datasets, often characterized by extensive nonlinearities and interactions, are often best analyzed using machine learning (ML) or other artificial intelligence (AI) approaches. In this article, we review several case studies where ML has been used to model aspects of agricultural production systems and provide information useful for farm-level management decisions. These studies include modeling animal feeding behavior as a predictor of stress or disease, providing information important for developing precise and efficient irrigation systems, and enhancing tools used to recommend optimum levels of nitrogen fertilization for corn. Taken together, these examples represent the current abilities and future potential for AI applications in agricultural production systems.

Tile-Drain and Denitrification Bioreactor Water Chemistry for a Soybean (<i>Glycine max</i>(L.) Merr.)-Corn (<i>Zea mays</i> L.) Rotation in East-Central Missouri (USA)

Nitrogen transport from agriculture production fields raises the specter of environmental degradation of freshwater resources. Our objectives were to document and evaluate nitrate-N, ammonium-N, phosphorus and other nutrients emanating from a 40-ha controlled subsurface irrigation drainage technology coupled in series with a denitrification bioreactor. The intent of the denitrification bioreactor is to create an environment for anoxic microbial populations to support denitrification. We monitored the tile-drainage effluent and denitrification bioreactor water chemistry under a corn-soybean rotation to estimate the nutrient concentrations and the competence of the denitrification bioreactor to foster denitrification. Nitrate-N bearing tile drainage effluents ranged from less than 1.5 to 109 mg NO3- -N/L, with the nitrate concentration differences attributed primarily to the: 1) timing of nitrogen fertilization for corn, 2) soil mineralization and residue decomposition, and 3) intense rainfall events. The denitrification bioreactor was highly effective in reducing drainage water nitrate-N concentrations providing the rate of water flow through the denitrification bioreactor permitted sufficient time for equilibrium to be attained for the nitrate reduction reactions. The nitrate-N concentrations entering the denitrification bioreactor ranged from 0.4 to 103 mg NO3- -N/L in 2018, whereas the outlet nitrate concentrations typically ranged from 0.3 to 5.2 mg NO3- -N/L in 2018. Nitrate tile-drainage effluent concentrations in 2019 were marginal, given soybeans obtain nitrogen from biological nitrogen fixation. Nutrient uptake by corn reduced the soil nitrate leaching pool and created nitrogen-bearing biomass, features important for formulating best management practices.

Soil Texture and Precipitation Influence Optimal Time of Nitrogen Fertilization for Corn

Core Ideas Soil texture and precipitation largely impact split fertilizer application efficacy.Split fertilizer application consistently increased grain yield in irrigated sands.In fine‐texture and well distributed rain, split application should be done by V8.In fine‐texture and poor distributed rain, split application made no yield difference.Corn response to split application was greater in coarse‐textured than fine‐textured soils. In‐season N fertilization is increasingly being used as a management strategy to reduce risk of N loss to the environment. This study evaluated the optimal timing for a split N fertilizer application in corn (Zea mays L.) across different environments and soil textural classes in Minnesota. Treatments consisted of pre‐plant (PP) urea applied at 0 to 270 or 315 kg N ha−1 on increments of 45 kg N ha−1 and five split applications (SA) of 45 kg N ha−1 urea ammonium nitrate as starter fertilizer and 90 kg N ha−1 of urea with an urease inhibitor applied at the V2, V4, V6, V8, or V12 stage of corn phenological development. Site‐years were grouped according to grain yield response to fertilizer timing. Irrigated coarse‐textured soils produced 1.5‐ to 1.9‐fold greater grain yield when fertilizer was split applied from V4 to V12 due to improved synchrony of N availability to crop demand and reduced potential for NO3–N leaching. Rainfed, fine‐textured soils had mixed results. Site‐years receiving well‐distributed precipitation produced greater grain yield when fertilizer was split applied from V2 to V8, but early season N deficiency reduced yield for the V12 application. Site‐years with limited precipitation during the late vegetative through grain filling stages of corn had no improvement in grain yield or N use efficiencies for SA because dry soil conditions likely interfered with root development and made N fertilizer positionally unavailable to the crop. This study highlights that the success of SA is largely dictated by soil texture and precipitation.

Corn Yield Intercropped With White Clover as Living Mulch

Brazil southern region edaphoclimatic conditions allow farmers to grow perennial winter legumes. However, at summer, a seasonality occurs in the production of these species allowing the grown of annual crops such as corn. In this way, interference between white clover (Trifolium repens L.) living mulch and corn crop (Zea mays L.) was studied using a clover sward established after one and two growing season in relation to the usual system of corn grown over black oat straw aiming to study the relationships occurring in this intercrop, such as white clover herbicide suppression, competition and its nitrogen effects on corn yield as well as its potential to became perennial after corn harvest. White clover suppression management was established in the main plots and corn nitrogen fertilization (0, 60, 120, 180 kg ha-1) was performed in the subplots (4.2 × 8 m) in a randomized block design with four replications. White clover suppression managements were: (i) partial suppression achieved by mowing the plots at the corn seeding day; (ii) partial suppression achieved by mowing plus chemically broadcast application of 2.4-D; (iii) partial suppression achieved by a chemically broadcast application of glyphosate. Corn grain yields ranged from 3.0 to 12.2 Mg ha-1. Nitrogen input and herbicide management are important elements to reduce white clover competition and increase corn yield. It is possible to manage white clover as living mulch in corn with its full recovery after corn harvest without replanting. Clover with 1 cycle is easier suppressed than perennial clover sward and can be handled in intercropping with corn without affecting grain yield, with ability to resume growth in the next growing season.

Use of Some Organic and Bio Fertilizers as a Partial Substitution of the Mineral Nitrogen Fertilization for Corn

Use of Some Organic and Bio Fertilizers as a Partial Substitution of the Mineral Nitrogen Fertilization for Corn

Soil-surface carbon dioxide emission following nitrogen fertilization in corn

Improvement in use efficiency of N fertilizers can potentially better sustain agriculture by reducing N2O emissions from soils, but little is known about its impact on soil CO2 emissions. A study, involving both a field experiment and a laboratory incubation, was conducted in eastern Canada to determine the N fertilization effect on soil CO2 emissions. In laboratory, we incubated nine different types of soil with and without 150 kg N ha−1 as KNO3 or (NH4)2SO4. The N-fertilized soils had lower CO2 emissions compared with the no-N control soils for six of them. Among fertilizer sources, emissions of CO2 were on average 22% lower with KNO3 than with (NH4)2SO4. The field experiment conducted on a clay soil included three sources of N (urea-NH4NO3, CaNH4NO3, and aqua NH3) at 0–200 kg N ha−1 band-incorporated at the six-leaf corn stage. Under field conditions, most CO2 was emitted between N application and grain maturity with cumulative seasonal soil emissions greater in the control (4.9 Mg C ha−1) than in the N treatments (average of 4.0 ± 0.3 Mg C ha−1). Evidence suggested that both heterotrophic and autotrophic respiration seemed affected, whereas the NO3-based source had a more depressing effect on CO2 emissions than did the NH4 source.

Use efficiency of variable rate of nitrogen prescribed by optical sensor in corn

ABSTRACT The efficiency of nitrogen fertilizer in corn is usually low, negatively affecting plant nutrition, the economic return, and the environment. In this context, a variable rate of nitrogen, prescribed by crop sensors, has been proposed as an alternative to the uniform rate of nitrogen traditionally used by farmers. This study tested the hypothesis that variable rate of nitrogen, prescribed by optical sensor, increases the nitrogen use efficiency and grain yield as compared to uniform rate of nitrogen. The following treatments were evaluated: 0; 70; 140; and 210 kg ha-1 under uniform rate of nitrogen, and 140 kg ha -1 under variable rate of nitrogen. The nitrogen source was urea applied on the soil surface using a distributor equipped with the crop sensor. In this study, the grain yield ranged from 10.2 to 15.5 Mg ha-1, with linear response to nitrogen rates. The variable rate of nitrogen increased by 11.8 and 32.6% the nitrogen uptake and nitrogen use efficiency, respectively, compared to the uniform rate of nitrogen. However, no significant increase in grain yield was observed, indicating that the major benefit of the variable rate of nitrogen was reducing the risk of environmental impact of fertilizer.

Solar photovoltaic powered on-site ammonia production for nitrogen fertilization

Ammonia synthesis is the most important step for nitrogen-fertilizer production and consumes approximately 1% of the world’s energy production and energy-related greenhouse gas emissions. In addition to the concomitant emissions caused by ammonia and nitrogen fertilizer synthesis, centrally produced fertilizer that must be distributed to farms also harms the environment because of the embodied energy of transportation. An environmentally-optimal nitrogen fertilizer system would be distributed on farms themselves using only renewable inputs. Recent developments in solar photovoltaic technology and subsystems for ammonia production have made non-organic on-site ammonia production physically possible. This study provides a technical evaluation of the process for on-site nitrogen-fertilization of corn using solar photovoltaic electricity as the energy input. The system consists of a water electrolysis system to generate hydrogen and a membrane system to generate nitrogen needed as material inputs. Total power consumption for syngas preparation to generate a unit of ammonia is calculated. System total energy consumption is calculated while compensating syngas preparation with heat recovery. Five case-study locations are evaluated to determine their suggested nitrogen fertilizer addition (N-rate) for corn growth and the energy consumption for suggested N-rate is calculated. The System Advisor Model (SAM) is then used to simulate the PV system output for those five locations. Finally, the PV land use required as a fraction of the corn field area is determined. The results indicate that because PV is so much more efficient at solar energy conversion than organic methods, even the worst case evaluated in Indiana requires less than 1% of the corn field converted to a PV system to provide enough energy to generate sufficient amounts of ammonia for fertilizer for the remaining corn. The system was modeled to provide ammonia to fertilize for corn fields larger than 1079 acres with the worst soil conditions, the area of which applies to more than half of cropland in the U.S. in 2011. As the finiteness and emissions of fossil fuel production of nitrogen become more important, this renewable system should become economical and future investigations into its overall viability are warranted.

Economics and nitrogen fertilization for corn and wheat in the Northern Great Plains

The traditional response of crop to N graph is a linear/plateau model, which has some problems. In contrast, most N rate studies result in a quadratic model. Economists are familiar with the quadratic input rate response and call it “the law of diminishing returns.” New research‐based N rate calculation tools in North Dakota and Montana are based on this. Earn 0.5 CEUs in Nutrient Management by reading this article and taking the quiz at www.certifiedcropadviser.org/certifications/self‐study/725

Corn Nitrogen Fertilization Requirement and Corn-Soybean Productivity with a Rye Cover Crop

Winter rye (Secale cereale L.) cover crop (RCC) has potential to reduce NO3–N loss from corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] fields. However, RCC effects on annual crop productivity and corn optimal N fertilization requirement are unclear. The objectives were to evaluate corn and soybean yield response to RCC and corn optimal N rate. Treatments were no-RCC and RCC with six fertilizer N rates (0–225 kg N ha-1) applied to corn in a no-till corn–soybean (CS) rotation at four Iowa sites in 2009 through 2011. The RCC biomass and N uptake was low, with a maximum of 1280 kg dry matter (DM) ha-1 and 26 kg N ha-1, respectively. In the no-N control, the RCC reduced soil profile NO3–N by 15 kg N ha-1 only at time of RCC control before corn planting. Corn canopy sensing, plant height, and plant population indicated more N stress, reduced plant stand, and slower growth with RCC. The RCC reduced corn grain yield by 6% at the economic optimum N rate (EONR). The EONR was the same with no-RCC and RCC, but plant N uptake efficiency (PUE) was reduced at low N rates with RCC, but not above the EONR. Soybean yield was not affected by RCC. Results indicate N fertilization rate should be the same with or without RCC. Improvement in RCC systems and management could make RCC a more viable practice within no-till corn and soybean production.

Spacing, population density and nitrogen fertilization in corn grown in an Oxisoil

The objective of this study was to evaluate yield components, leaf nitrogen content and grain yield in corn as affected by row spacing, plant density and nitrogen topdressing. The experiment was conducted with the single-cross hybrid AG 8021, in the municipality of Toledo-PR, in an Oxisoil under no-tillage system, in the crop year 2005/ 2006. The experiment was arranged in a randomized block design and treatments in split-split-plots, with four replications. The two row spacings (0.45 and 0.90 m) were allocated in the main plots, the two plant densities (60,000 and 80,000 plants ha-1) were allocated in the subplots and the three nitrogen rates (80, 100, 120 and 140 kg ha-1 N) were allocated in the sub-subplots. Topdress nitrogen was applied using urea as N source. The rise of the plant population from 60,000 to 80,000 plants ha-1 and the application of topdress nitrogen resulted in increased production components. The application of topdress fertilization provided increase in leaf N content and grain yield for the spacings 0.45 m and 0.90 m. Yield was higher in the spacing 0.45 m than 0.90 m. Yield was higher with 60,000 plants than with 80,000 plants at 0.90 m, while at 0.45 m there was no difference in relation to the plant density.

Optical crop sensor for variable-rate nitrogen fertilization in corn: i - plant nutrition and dry matter production

Variable-rate nitrogen fertilization (VRF) based on optical spectrometry sensors of crops is a technological innovation capable of improving the nutrient use efficiency (NUE) and mitigate environmental impacts. However, studies addressing fertilization based on crop sensors are still scarce in Brazilian agriculture. This study aims to evaluate the efficiency of an optical crop sensor to assess the nutritional status of corn and compare VRF with the standard strategy of traditional single-rate N fertilization (TSF) used by farmers. With this purpose, three experiments were conducted at different locations in Southern Brazil, in the growing seasons 2008/09 and 2010/11. The following crop properties were evaluated: above-ground dry matter production, nitrogen (N) content, N uptake, relative chlorophyll content (SPAD) reading, and a vegetation index measured by the optical sensor N-Sensor® ALS. The plants were evaluated in the stages V4, V6, V8, V10, V12 and at corn flowering. The experiments had a completely randomized design at three different sites that were analyzed separately. The vegetation index was directly related to above-ground dry matter production (R² = 0.91; p<0.0001), total N uptake (R² = 0.87; p<0.0001) and SPAD reading (R² = 0.63; p<0.0001) and inversely related to plant N content (R² = 0.53; p<0.0001). The efficiency of VRF for plant nutrition was influenced by the specific climatic conditions of each site. Therefore, the efficiency of the VRF strategy was similar to that of the standard farmer fertilizer strategy at sites 1 and 2. However, at site 3 where the climatic conditions were favorable for corn growth, the use of optical sensors to determine VRF resulted in a 12 % increase in N plant uptake in relation to the standard fertilization, indicating the potential of this technology to improve NUE.

Optical crop sensor for variable-rate nitrogen fertilization in corn: II - indices of fertilizer efficiency and corn yield

Generally, in tropical and subtropical agroecosystems, the efficiency of nitrogen (N) fertilization is low, inducing a temporal variability of crop yield, economic losses, and environmental impacts. Variable-rate N fertilization (VRF), based on optical spectrometry crop sensors, could increase the N use efficiency (NUE). The objective of this study was to evaluate the corn grain yield and N fertilization efficiency under VRF determined by an optical sensor in comparison to the traditional single-application N fertilization (TSF). With this purpose, three experiments with no-tillage corn were carried out in the 2008/09 and 2010/11 growing seasons on a Hapludox in South Brazil, in a completely randomized design, at three different sites that were analyzed separately. The following crop properties were evaluated: aboveground dry matter production and quantity of N uptake at corn flowering, grain yield, and vegetation index determined by an N-Sensor® ALS optical sensor. Across the sites, the corn N fertilizer had a positive effect on corn N uptake, resulting in increased corn dry matter and grain yield. However, N fertilization induced lower increases of corn grain yield at site 2, where there was a severe drought during the growing period. The VRF defined by the optical crop sensor increased the apparent N recovery (NRE) and agronomic efficiency of N (NAE) compared to the traditional fertilizer strategy. In the average of sites 1 and 3, which were not affected by drought, VRF promoted an increase of 28.0 and 41.3 % in NAE and NRE, respectively. Despite these results, no increases in corn grain yield were observed by the use of VRF compared to TSF.

Desempenho agronômico da cultura do milho e espécies forrageiras em sistema de Integração Lavoura-Pecuária no Cerrado

O consórcio entre culturas leva à competição por fatores de produção como água, luz e nutrientes, porém, atualmente, é comum o cultivo integrado do milho com forrageiras para recuperação e renovação de pastagens degradadas, diversificação na renda dos produtores e produção de massa seca para sustentabilidade da agricultura. O objetivo deste trabalho foi avaliar o desempenho agronômico e o teor de nitrogênio da cultura do milho consorciado com forrageiras dos gêneros Panicum e Brachiaria. O delineamento experimental foi o de blocos casualizados, com quatro repetições. O experimento foi constituído de oito tipos de consórcio do milho com: Panicum maximum cv. 'Tanzânia', semeado simultaneamente (MTS) ou por ocasião da adubação nitrogenada de cobertura do milho (MTC); Panicum maximum cv. 'Mombaça', semeado simultaneamente (MMS) ou por ocasião da adubação nitrogenada de cobertura (MMC); Brachiaria brizantha cv. 'MG-5', semeado simultaneamente (MBS) ou por ocasião da adubação nitrogenada de cobertura (MBC); Brachiaria ruziziensis, semeado simultaneamente (MRS) ou por ocasião da adubação nitrogenada de cobertura (MRC), além do cultivo do milho sem consorciação (MSC). Quando a cultura do milho atingiu o estádio V6, procedeu-se à adubação de cobertura com 100kg ha-1 de N para os 9 tratamentos. Os consórcios de forrageiras dos gêneros Panicum e Brachiaria com o milho não afetam o teor N foliar, os componentes de produção e a produtividade de grãos de milho, quando comparados com o cultivo solteiro. As maiores produtividades de massa seca das forrageiras foram nos consórcios semeados na ocasião da adubação nitrogenada de cobertura do milho.

Utilization of Dry Distillers Grains and Charcoal as Nitrogen Fertilizer in Corn

Increasing bioenergy production will result in increased by‐products which will need proper disposal methods to prevent economic and/or ecological problems. Land application has potential for disposal and/or nutrient cycling if these by‐products have crop nutritive value. Our objective was to compare the fertilizer effects of two by‐products of bioenergy production, dry distillers grains with solubles (DDGs) and charcoal with urea in corn (Zea mays L.) and evaluate nutrient uptake. Treatments were DDGs under no‐till and tilled at four location‐years and charcoal under no‐till and tilled at three location‐years. No‐till urea was used as a baseline at all location‐years. Nitrogen rates ranged from 0 to 180 kg N ha−1. All materials were spring applied before tillage and planting. Corn yields for DDGs and urea were similar across tillage treatments and locations. Corn yields over all charcoal rates and tillage treatments were the same as 0 kg N ha−1. The charcoal, because of immobilization or lack of decomposition, did not contribute to the corn N nutrition. Neither material showed any negative effects on the corn yields. Stalk N, P, K, and grain N followed expected trends and had few effects compared with those from urea. Land application of DDGs and charcoal has merit for disposal/N cycling with DDGs being preferred for its N contribution.

Reduced Nitrogen Fertilization to Corn following Alfalfa in an Irrigated Semiarid Environment

Nitrogen fertilization of corn (Zea mays L.) following alfalfa (Medicago sativa L.) can be reduced due to the considerable amounts of N released by this legume, but most research on this subject has been conducted in rainfed areas. The objective of this study was to determine the response of corn to N fertilization following high‐yielding alfalfa in irrigated semiarid conditions. Seven field experiments were conducted between 2006 and 2008 in the Ebro Valley, Northeast Spain. Fields were sprinkler, furrow, or flood irrigated. Treatments comprised six N rates (0, 50, 100, 150, 200, and 300 kg N ha−1) applied to corn as two sidedressings. The N contained in the alfalfa roots and crowns ranged from 54 to 212 kg N ha−1, depending on the field. Alfalfa provided enough N to the subsequent corn to achieve from 10.3 to 16.7 Mg ha−1 of grain yield without N fertilization. Nitrogen fertilization was not required to maximize corn yields in three of seven fields. In the other four sites, the optimum nitrogen rates (ONR) that maximized corn yields ranged from 115 to 196 kg N ha−1 The highest ONR generally were observed in flood‐irrigated fields than in sprinkler‐irrigated fields. Net economic return from N fertilization was maximized at N rates between 0 and 150 kg N ha−1, suggesting that N applications for corn succeeding alfalfa can be greatly reduced compared to rates normally applied in irrigated semiarid areas (300 kg N ha−1).

Effect of Nitrogen Fertilizer Application on Growing Season Soil Carbon Dioxide Emission in a Corn–Soybean Rotation

Nitrogen application can have a significant effect on soil carbon (C) pools, plant biomass production, and microbial biomass C processing. The focus of this study was to investigate the short-term effect of N fertilization on soil CO(2) emission and microbial biomass C. The study was conducted from 2001 to 2003 at four field sites in Iowa representing major soil associations and with a corn (Zea mays L.)-soybean (Glycine max L. Merr.) rotation. The experimental design was a randomized complete block with four replications of four N rates (0, 90, 180, and 225 kg ha(-1)). In the corn year, season-long cumulative soil CO(2) emission was greatest with the zero N application. There was no effect of N applied in the prior year on CO(2) emission in the soybean year, except at one of three sites, where greater applied N decreased CO(2) emission. Soil microbial biomass C (MBC) and net mineralization in soil collected during the corn year was not significantly increased with increase in N rate in two out of three sites. At all sites, soil CO(2) emission from aerobically incubated soil showed a more consistent declining trend with increase in N rate than found in the field. Nitrogen fertilization of corn reduced the soil CO(2) emission rate and seasonal cumulative loss in two out of three sites, and increased MBC at only one site with the highest N rate. Nitrogen application resulted in a reduction of both emission rate and season-long cumulative emission of CO(2)-C from soil.