Controlled-release urea (CRU) mixed with conventional urea can promoting grain yield (GY). Whether deep placement of mixed nitrogen fertilizer can further enhance GY, nitrogen use efficiency is rarely reported. In this study, four CRU-urea mixtures and two fertilizer placement depths were tested on rainfed spring maize. Fertilizer placement at a depth of 16 cm created a soil environment of lower temperature and higher water content than that at a depth of 8 cm. Increasing the fertilizer depth or the CRU ratio increased DM and total plant N content at maturity, but lowered N remobilization efficiency (NRE) and DW remobilization efficiency (DRE). Maximum GY and partial factor productivity of nitrogen (PFP_N) were achieved when CRU and urea were mixed at a ratio (1:0 and 2:1) and the fertilizer was placed at a depth of 16 cm. Although fertilizer deep placement increased production inputs, the increase in net benefits was even more dramatic, especially when CRU was mixed with urea. In summary, a 2:1 mixture of CRU and conventional urea is the most promising fertilization strategy for spring maize production, particularly when combined with 16 cm deep fertilizer placement.

控释尿素（CRU）与常规尿素混合可以提高谷物产量（GY）。深度施用混合氮肥是否可以进一步提高GY，很少报道氮的利用效率。在这项研究中，在雨养春玉米上测试了四种CRU-尿素混合物和两种肥料放置深度。与在8厘米深度处相比，在16厘米深度处放置肥料可创造出温度更低，含水量更高的土壤环境。增加肥料深度或CRU比例会增加成熟期的DM和植物总N含量，但降低N转运效率（NRE）和DW转运效率（DRE）。氮的最大GY和分项生产率（PFP _N当将CRU和尿素按比例（1：0和2：1）混合并将肥料放置在16 cm的深度时，可达到）。尽管深施肥料增加了生产投入，但净收益的增加甚至更为显着，特别是当CRU与尿素混合时。总之，CRU和常规尿素的2：1混合物是春季玉米生产中最有希望的施肥策略，尤其是与16 cm深的肥料组合时。