Rice yield and economic response to micronutrient application in Tanzania

Nutrient deficiencies limit rice production in sub-Saharan Africa. The conventional recommended remedy for this is the soil application of fertilizers composed macro-nutrients, N, P and K, whereas crop micronutrient requirements are neglected. This leads to nutrient mining diminished fertiliser use efficiency. Application micronutrients along with NPK rates can prevent boost yields. In study, we assessed productivity profitability different soil- foliar-applied 30 on-farm trials per year two consecutive years (2015, 2016) Tanzania, East Five locally available foliar formulations (combinations macro- or alone) (3?2?7.5?10 Zn-B-Mg-S kg ha–1) were under NPK-fertilization regimes (80?17.5?33.2 0?0?0 N-P-K three growing environments (RGEs): Irrigated Lowland (IL), Rainfed (RL), Upland (RU). effect applied on yield was consistent IL but highly variable RL RU conditions across years. absence ineffective any RGEs. IL, without NPK, alone increased by 0.3?0.4 t ha–1, compared control (3.1 ha–1). Only 1 while 1.5 control. benefit-cost (B:C) ratio 4–4.5 alone. RL, 2015 from 2.7 5.0 ha–1 6.8 ha–1. However, a drought incidence 2016 nullified effect. With products (F2 F3) significantly highest B:C obtained (B:C 14), 7 7.2, respectively. RU, no significant differences observed among treatments year, likely due drought. Foliar effective only drought-free environments. study demonstrated that together yields drought-stress. macronutrients prerequisite maximizing benefits applying increase Tanzania.