Updating North Carolina Corn Yields and Nitrogen Recommendations to Match Current Production Practices and New Hybrids

Rajkovich, Shelby R.; Crozier, Carl R.; Smyth, Thomas J.; Crouse, David A.; Osmond, Deanna L.

doi:10.2134/cftm2014.0085

Cited by 12 publications

(17 citation statements)

References 28 publications

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“…Arrows indicate estimated economic optimum N rates. and North Carolina [Rajkovich et al, 2015;1.43 × 10 -2 to 1.79 × 10 -2 kg N (kg grain) -1 or 0.8-1.0 lb N bu -1 ].…”

Section: Internal Nitrogen Requirementmentioning

confidence: 99%

Strengths and Limitations of Nitrogen Rate Recommendations for Corn and Opportunities for Improvement

et al. 2018

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A gronomy J our n al • Volume 110 , I ssue 1 • 2 018 1 T he goal of an N recommendation system is to accurately estimate the gap between the N provided by the soil and the N required by the plant. Accurately estimating this gap depends on the ability of the recommendation system to accurately estimate fi eld or subfi eld specifi c economically optimal nitrogen rates (EONR). Current recommendation systems are not as accurate as needed to provide consistently reliable estimates of N needs across years at the fi eld or subfi eld scale. Uncontrollable factors like temperature, rainfall timing, intensity and amount, and interactions of temperature and rainfall with factors such as N source, timing and placement, plant genetics, and soil characteristics combine to make N rate recommendations for an individual fi eld or rates for subfi elds a process guided as much by science as by the best professional judgement of farmers and farm advisors.Substantial evidence has accumulated that EONRs can vary widely across fi elds, within fi elds and over years in the same fi eld for a wide range of crops and geographies. Examples ABSTRACTNitrogen fi xation by the Haber-Bosch process has more than doubled the amount of fi xed N on Earth, signifi cantly infl uencing the global N cycle. Much of this fi xed N is made into N fertilizer that is used to produce nearly half of the world's food. Too much of the N fertilizer pollutes air and water when it is lost from agroecosystems through volatilization, denitrifi cation, leaching, and runoff . Most of the N fertilizer used in the United States is applied to corn (Zea mays L.), and the profi tability and environmental footprint of corn production is directly tied to N fertilizer applications. Accurately predicting the amount of N needed by corn, however, has proven to be challenging because of the eff ects of rainfall, temperature, and interactions with soil properties on the N cycle. For this reason, improving N recommendations is critical for profi table corn production and for reducing N losses to the environment. Th e objectives of this paper were to review current methods for estimating N needs of corn by: (i) reviewing fundamental background information about how N recommendations are created; (ii) evaluating the performance, strengths, and limitations of systems and tools used for making N fertilizer recommendations; (iii) discussing how adaptive management principles and methods can improve recommendations; and (iv) providing a framework for improving N fertilizer rate recommendations.

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“…Arrows indicate estimated economic optimum N rates. and North Carolina [Rajkovich et al, 2015;1.43 × 10 -2 to 1.79 × 10 -2 kg N (kg grain) -1 or 0.8-1.0 lb N bu -1 ].…”

Section: Internal Nitrogen Requirementmentioning

confidence: 99%

Strengths and Limitations of Nitrogen Rate Recommendations for Corn and Opportunities for Improvement

et al. 2018

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“…Therefore, these results suggest that private farms had more enriched surface soil than on research stations. Furthermore, historical calibrations of N fertilizer requirement for corn in North Carolina, which would have been conducted primarily on research stations (Rajkovich et al, 2015), may not have captured the full range of soil conditions found on private farms. Irrespective of location, these results suggest there can be a large quantity of mineralizable N present in surface soil to provide a significant fraction of N to a cropping system.…”

Section: Net Nitrogen Mineralizationmentioning

confidence: 99%

Soil‐Test Biological Activity with the Flush of CO₂: I. C and N Characteristics of Soils in Corn Production

Franzluebbers¹,

Pershing

Crozier

et al. 2018

Soil Science Soc of Amer J

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Nitrogen limits crop production when insufficient and harms the environment when excessive. Tailoring N inputs to cropping systems remains a high priority to achieve production and environmental goals. We collected soils from 47 corn (Zea mays L.) production fields in North Carolina and Virginia at depths of 0 to 10, 10 to 20, and 20 to 30 cm and evaluated soil C and N characteristics in association with soil N mineralization. Soil organic C at a depth of 0 to 10 cm varied among sites from ~10 to 80 g kg -1 , and generally declined with depth because of many sites with no-tillage management. N itrogen (N) is considered the most limiting nutrient in plant production. In many cases, demand for N by highly productive crops far exceeds the N that can be supplied by soil. Sources of N from soil are residual inorganic N from previous cropping or organic forms of N in soil organic matter and plant and animal residues, which must be mineralized in synchrony with decomposition processes. Insufficient N leads to low biomass production as a result of limited protein synthesis and low photosynthetic activity, all of which causes cascading negative effects on water-use efficiency, biological activity, ecosystem functioning, economic return from farm capital investment, and social welfare of farming communities (Smil, 2002;Tilman et al., 2011). In contrast, excessive N leads to susceptibility of crops to invasion by pests, leakage of N from the soil and plant systems to the environment causing air and water pollution, and loss of investment from costly inorganic N inputs (Vitousek et al., 1997;Hatfield and Follett, 2008).Nitrogen availability in soils has been investigated for decades (Waksman and Starkey, 1924;Fribourg and Bartholomew, 1956;Stanford, 1968;Jenkinson and Powlson, 1976;Jansson and Persson, 1982;Campbell et al., 1991), yet reliable predictions of N fertilizer application rate to optimize cereal grain yields have been elusive (Balkcom et al., 2003). Early investigations to optimize inorganic N inputs focused on defining potentially mineralizable N from a nonlinear function derived from inorganic N released through successive leaching and incubation (Stanford and Smith, 1972). This methodology has been considered the best estimate of soil N mineralization potential, despite (i) the long time period for evaluation (32 wk Core Ideas• Soil nitrogen mineralization can be predicted with the flush of CO 2 .• Soil texture does not alter the relationship between the flush of CO 2 and N mineralization.• Large quantity of mineralizable N in surface soils is possible with conservation management.• The flush of CO 2 is an appropriate indicator for soil-test biological activity.• The flush of CO 2 is a rapid and reliable indicator of soil N availability.

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“…7C). This 121 kg N ha -1 discrepancy reflects a decision made by the North Carolina Nutrient Management Group in setting the RYE rate for Comus (historically high-yielding floodplain soil) higher than the LP average optimum N rate of around 80 kg N ha -1 (Rajkovich et al, 2015). The yield equation for x < 67 kg N ha -1 was y = 9547 + 101.9x (r 2 = 0.64 and p < 0.0001) and for x > 67 kg N ha -1 was y = 16,337 kg ha -1 .…”

Section: Regionmentioning

confidence: 99%

Evaluation of Nitrogen‐Loss Prevention Amendments in Maize and Wheat in North Carolina

et al. 2017

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Core Ideas Fertilizer additives to decrease N losses did not provide consistent yield advantages. Plots treated with N‐loss products did not increase N use efficiency or N uptake. Agronomic optimum N rates observed in the field aligned with North Carolina recommendations. To reduce environmental losses of N and increase crop use, it is critical to optimize N fertilization rates and determine if N‐loss prevention amendments increase yields. Research objectives were to: (i) determine N‐release patterns of three N‐loss amendments (urea ammonium nitrate [UAN] treated with NBPT+DCD, nitrapyrin, or an organo‐Ca) and UAN through a laboratory incubation; (ii) determine effectiveness of these four products for maize (Zea mays L.) and winter wheat (Triticum aestivum L.) produced in two to three regions of North Carolina; and (iii) determine agronomic optimum N rate for wheat and corn compared to state‐recommended rates. Nitrogen release was measured in three soils (coastal plain, piedmont, and mountains) during the incubation experiment. Field experiments were randomized complete block designs (four replications of six maize N rates and five wheat N rates), with each rate applied as one of four product treatments (UAN and UAN+ one of three N‐loss prevention amendments). In the incubation experiment, soils treated with UAN+nitrapyrin or UAN+NBPT+DCD delayed nitrification longer than soils treated with UAN or UAN+organo‐Ca. There was no significant effect of product on maize grain yield (coastal plain and mountains) and wheat yield (coastal plain and piedmont). A year × product interaction occurred for maize grain yield in the piedmont. Agronomic optimum N rates mostly aligned with current North Carolina N fertilizer recommendations. Despite positive laboratory results, N‐loss amendments did not have a significant effect on yield in 9 of 10 site‐years, indicating that proper N rates are a more effective nutrient management strategy.

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Updating North Carolina Corn Yields and Nitrogen Recommendations to Match Current Production Practices and New Hybrids

Cited by 12 publications

References 28 publications

Strengths and Limitations of Nitrogen Rate Recommendations for Corn and Opportunities for Improvement

Strengths and Limitations of Nitrogen Rate Recommendations for Corn and Opportunities for Improvement

Soil‐Test Biological Activity with the Flush of CO₂: I. C and N Characteristics of Soils in Corn Production

Evaluation of Nitrogen‐Loss Prevention Amendments in Maize and Wheat in North Carolina

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Updating North Carolina Corn Yields and Nitrogen Recommendations to Match Current Production Practices and New Hybrids

Cited by 12 publications

References 28 publications

Strengths and Limitations of Nitrogen Rate Recommendations for Corn and Opportunities for Improvement

Strengths and Limitations of Nitrogen Rate Recommendations for Corn and Opportunities for Improvement

Soil‐Test Biological Activity with the Flush of CO2: I. C and N Characteristics of Soils in Corn Production

Evaluation of Nitrogen‐Loss Prevention Amendments in Maize and Wheat in North Carolina

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Product

Resources

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Soil‐Test Biological Activity with the Flush of CO₂: I. C and N Characteristics of Soils in Corn Production