This study aimed to develop a novel regression model for prescription of required nitrogen (N) for maize by combining spectral reflectance data from GreenSeeker sensor and agronomic efficiency. For this end, two field trials at two sites were carried out with maize (Zea mays L.) on Oxisols under no-till systems in Southern Brazil. For both experiments, a randomized complete block design, with three replications in a split-plot arrangement, was used. The main plots consisted of four urea-N rates at sowing (0, 20, 40, and 60 kg N ha⁻¹) and subplots included four urea-N rates in top dressing (0, 80, 160, and 240 kg N ha⁻¹). Based on the results, a novel model for prescription of N rate in top dressing for maize was defined. The increases in maize yields with the N rates estimated by the model (16% to 39%) were similar to that obtained with the N rates used for maximum economic yield (15% to 42%). The estimated N rate by the model provided an economic return 36.5% and 7.0% higher than the N rate for maximum yield, and only 6.6% and 2.0% lower than the N rate for maximum economic yield, at sites 1 and 2, respectively. Thus, the economic return obtained using the model was closer to that reached with the N rate for maximum economic yield than that for maximum yield. Therefore, the developed model, combining spectral reflectance and agronomic efficiency, exhibited great potential to improve the maize N fertilization efficiency.

这项研究旨在通过结合GreenSeeker传感器的光谱反射率数据和农艺效率来开发玉米所需氮（N）处方的新型回归模型。为此，在巴西南部的免耕系统下，使用玉米（Zea mays L.）在Oxisol上进行了两个田间试验。对于这两个实验，均使用了随机完整的块设计，并在拆分图布置中进行了三个重复。主要地块包括播种时的四个尿素氮含量（0、20、40和60 kg N ha ^-1），子图包括追肥中的四个尿素氮含量（0、80、160和240 kg N ha）^-1）。在此基础上，建立了玉米追施氮肥比例的新模型。通过模型估算的氮肥利用率（16％至39％），玉米单产的增幅与最大经济产量的氮肥利用率（15％至42％）相似。通过模型估算的氮肥利用率，分别在站点1和2处分别提供了比最高氮肥利用率高出36.5％和7.0％的经济收益，而对于氮磷钾肥最高产量仅低了6.6％和2.0％的经济收益。因此，使用该模型获得的经济收益与最大收益的N率相比更接近N率。因此，开发的模型将光谱反射率和农艺效率相结合，具有提高玉米氮肥利用率的巨大潜力。