Nitrogen leaching and indirect nitrous oxide emissions from fertilized croplands in Zimbabwe uri icon

abstract

  • Agricultural efforts to end hunger in Africa are hampered by low fertilizer-use-efficiency exposing applied nutrients to losses. This constituteseconomic losses and environmental concerns related to leaching and greenhouse gas emissions. The effects of NH4NO3 (0, 60 and 120 kg N ha-1) on N uptake, N-leaching and indirect N2O emissions were studied during three maize (Zea mays L.) cropping seasons on clay (Chromic luvisol) and sandy loam (Haplic lixisol) soils in Zimbabwe. Leaching was measured using lysimeters, while indirect N2O emissions were calculated from leached N using the emission factor methodology. Results showed accelerated N-leaching (3?26 kg ha-1 season-1) and N-uptake (10?92 kg ha-1) with N input. Leached N in groundwater had potential to produce emission increments of 0?94 g N2O-N ha-1 season-1 on clay soil, and 5?133 g N2ON ha-1 season-1 on sandy loam soil following theapplication of NH4NO3. In view of this short-term response intensive cropping using relatively high N rate may be more appropriate for maize in areas whosesoils and climatic conditions are similar to those investigated in this study, compared with using lower N rates or no N over relatively larger areas to attain atargeted food security level

publication date

  • 2012