Nitrogen management strategies for smallholder maize production systems: Yield and profitability variability

Document Type: Research Paper

Authors

1 Smallholder Cropping Systems Program, SPAF, Federal University of Pelotas, UFPEL, Pelotas, RS, Brazil.

2 Embrapa Maize and Sorghum, Rod. MG 424, Km 45, Zona Rural, P.O. Box 151, ZIP Code 35702-098, Sete Lagoas, MG, Brazil

3 Embrapa Maize and Sorghum, Rod. MG 424, Km 45, Zona Rural, P.O. Box 151, ZIP Code 35702-098, Sete Lagoas, MG, Brazil.

4 Department of Agronomy and Plant Genetics, University of Minnesota, Southwest Research & Outreach Center 23669 130th Street Lamberton, MN 56152, USA

5 Assistant Professor, UNIFEMM, Sete Lagos, MG, Brazil.

6 Minas Gerais State Extension Service, Emater-MG, Sete Lagoas, MG, Brazil

7 AgWeatherNet, Washington State University, 24106 North Bunn Road, Prosser, Washington, 99350-8694, USA.

Abstract

Maize (Zea mays L.) production requires large amounts of nitrogen (N) that
directly affect production cost. Poultry litter can be used as an alternative source of
N. To optimize its use, poultry litter requires technical and economic feasibility
analyses. Crop simulation models have proven to be efficient tools to support this
type of research. The objectives of this study were to determine yield and net return
of maize production fertilized with both mineral fertilizer and poultry litter. High
inter-annual variation was observed in simulated yield for all fertilization strategies
evaluated. The higher the mineral N rate, the higher the yield. Among the treatments
fertilized with poultry litter the highest yield was obtained with a rate equivalent to
240 kg ha-1 of N. The trend of the economic net return for the different rates of
mineral fertilizers was in the opposite direction of the trend in yield, i.e., the higher
the rate of mineral fertilizer, the lower the economic return. Among the poultry litter
fertilization strategies, the average economic net return increased up to a rate
equivalent to 210 kg ha-1 of N, decreasing for higher rates. Poultry litter rates
equivalent to 120 to 300 kg ha-1 of N, economically exceeded all the mineral
fertilization strategies that were evaluated. Among all sources and rates, the highest
net return was obtained for a rate of 210 kg ha-1 of N as poultry litter. Higher rates
provided a lower net return and increased the likelihood of nitrate leaching.


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