Nitrogen fertilizer rate increases plant uptake and soil availability of essential nutrients in continuous maize production in Kenya and Zimbabwe.

摘要: Low fertilizer application rates for several decades have depleted soil nutrients in Sub-Saharan Africa (SSA) and contributed to relatively stagnant maize (Zea mays L.) yields. As is a staple crop, nutrient depletion has resulted major food insecurity. While one potential solution apply more nitrogen (N) fertilizer, previous studies SSA found yield responses be variable, likely because N often not the only limiting nutrient. This study aimed determine impact of consecutive applications on plant uptake available reserves non-N nutrients. Maize was grown continuously 3 sites that were representative ecosystem variability East/Southern (Embu, Kenya; Kiboko, Harare, Zimbabwe) at 4 different (0–160 kg N ha−1) from 2010 2015. Following final season, grain, stover, (sampled depths 0.9 m) samples analyzed essential Nitrogen increased P, S, Cu, Zn by up 280%, 320%, 420%, 210%, respectively, showing mitigating deficiencies 2 sites. Cumulatively, however, there net negative effect higher K, S soil-plant balances all Mn Cu balance indicating applying depletes enhances nutrients, balanced multiple needed sustainably increase yields SSA.