Reduced tillage (RT) systems have been promoted for crop production intensification in low potential areas through enhancement of fertiliser response of degraded soils and drought mitigation. A 3 year study was conducted from 2015/2016 to 2017/2018 growing seasons in sub-humid (650–1000 mm rainfall year⁻¹) Zimbabwe to determine nitrogen (N) uptake and maize yield response to nitrogen fertilisation rate (0, 30, 60, 90 120 150, 180 k gha⁻¹) under RT and conventional tillage (CT). The experimental design was a split plot, with the two tillage systems as main plot and seven N rates as the sub-plot treatments. Four sites were established in smallholder farmer fields with clayey soils (160–400 g clay kg⁻¹; Chromic Luvisols and Rhodic Ferralsols) and sandy soils (40–100 g clay kg⁻¹; Eutric Regosols). Results show that the study sites had rainfall deficits of 4–47% in the first and third growing seasons. Nitrogen uptake rates of 8–60 kg ha⁻¹ resulted in fertiliser N recovery efficiencies of 5–40% which were two fold higher under RT than under CT system. Maize grain yields (0.3–11 t ha⁻¹) were 33% higher under RT than CT and increased 1.88–2.72 fold under N fertilisation compared to the control. The mismatch between top dressed N and peak crop demand require precision fertilisation in the dry seasons. Agroecology based quadratic modelling revealed that maximum maize yields of 2–13 t ha⁻¹ were obtainable at optimum N fertilisation rates that were lower under RT than CT. The study provided a robust starting point in the improvement of nitrogen fertiliser management for maize under reduced tillage and climate variability.

通过提高退化土壤对肥料的响应和缓解干旱，在低潜力地区促进了耕作减少耕作制度。从2015/2016年至2017/2018年在津巴布韦半湿润（650–1000 mm降雨年^-1）的生长季节进行了为期3年的研究，以确定氮素吸收率和玉米产量对氮肥施用率的响应（0、30 ，60、90 120 150、180 k gha ^-1）在常规耕作（CT）下进行。实验设计是一个分割地块，以两个耕作系统为主地块，以七个氮肥作为次地块处理。在有黏土（160–400 g黏土kg ^-1的小农户农田）中建立了四个地点; 有色Luvisols和Rhodic Ferralsols）和沙质土壤（40–100 g粘土kg ^-1； Eurtric Regosols）。结果表明，在第一个和第三个生长季节，研究地点的降雨赤字为4–47％。氮吸收率为8–60 kg ha ^-1导致肥料氮的回收率为5–40％，在RT下比在CT系统下高出两倍。与对照相比，RT处理的玉米单产（0.3-11 t ha ^-1）比CT高33％，氮肥处理提高了1.88-2.72倍。追肥的氮素和农作物的峰值需求之间的不匹配要求在旱季进行精确的施肥。基于农业生态学的二次模型表明，最大玉米产量为2–13 t ha ^-1在RT下低于CT的最佳氮肥施用量下可获得最佳氮肥。该研究为改善耕种减少和气候多变性的玉米氮肥管理提供了一个强有力的起点。