Deep soils modify environmental consequences of increased nitrogen fertilizer use in intensifying Amazon agriculture.
Sci Rep
; 8(1): 13478, 2018 09 07.
Article
em En
| MEDLINE
| ID: mdl-30194382
ABSTRACT
Agricultural intensification offers potential to grow more food while reducing the conversion of native ecosystems to croplands. However, intensification also risks environmental degradation through emissions of the greenhouse gas nitrous oxide (N2O) and nitrate leaching to ground and surface waters. Intensively-managed croplands and nitrogen (N) fertilizer use are expanding rapidly in tropical regions. We quantified fertilizer responses of maize yield, N2O emissions, and N leaching in an Amazon soybean-maize double-cropping system on deep, highly-weathered soils in Mato Grosso, Brazil. Application of N fertilizer above 80 kg N ha-1 yr-1 increased maize yield and N2O emissions only slightly. Unlike experiences in temperate regions, leached nitrate accumulated in deep soils with increased fertilizer and conversion to cropping at N fertilization rates >80 kg N ha-1, which exceeded maize demand. This raises new questions about the capacity of tropical agricultural soils to store nitrogen, which may determine when and how much nitrogen impacts surface waters.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Solo
/
Glycine max
/
Zea mays
/
Fertilizantes
/
Produção Agrícola
/
Nitrogênio
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article