The development of technologies that provide rational and sustainable use of nitrogen fertilizers is among the priorities of agronomic research in 21^st century. Therefore, the objective of this study was to evaluate the effects of conventional urea or polymer-coated urea (PCU) on soil mineral nitrogen (N) content, plant dry mass and leaf N content in maize (Zea mays L.), cultivated in two seasons (first and second-crop) and in two regions of the Brazilian Cerrado (Chapadão do Sul - MS and Selvíria - MS). The treatments consisted of the combination of two sources of N (conventional urea or polymer-coated urea) and five doses of N (0, 45, 90, 135 or 180 kg ha⁻¹), in a randomized complete block design, with a 2 × 5 factorial scheme with four replications. The following parameters were evaluated: soil mineral N content (NH₄⁺, NO₃- and total mineral N), plant dry mass and leaf N content. Although the PCU did not change the NH₄⁺, NO₃- and total mineral N content in the soil, nor the dry mass of the plants, it provided, on average, higher N content in the leaves, when compared to CU. The increasing rates of N linearly increased the levels of NH₄⁺, NO₃- and total mineral N content in the soil, as well as the dry mass of the plants and the N content in the leaves, regardless of N source or study location.

的提供氮肥的合理和可持续利用技术的发展为农业研究21的优先事项之一^圣世纪。因此，本研究的目的是评估常规尿素或聚合物包被的尿素（PCU）对玉米栽培的玉米（Zea mays L.）土壤矿质氮（N）含量，植物干重和叶片N含量的影响。两个季节（第一季和第二季），以及巴西Cerrado的两个地区（Chapadãodo Sul-MS和Selvíria-MS）。处理包括两种氮源（常规尿素或聚合物涂覆的尿素）和五种氮素（0、45、90、135或180 kg ha ^{-1的组合）}），在随机完整块设计中，采用2×5阶乘方案，重复四次。评价了以下参数：土壤矿质氮含量（NH ₄ ⁺，NO _3-和总矿质氮），植物干重和叶片氮含量。尽管PCU不会改变土壤中的NH ₄ ⁺，NO _3-和总矿质N含量，也不会改变植物的干燥质量，但与CU相比，它平均提供了更高的叶片N含量。N的增加速率线性增加了土壤中NH ₄ ⁺，NO _3-和总矿质N的含量，以及植物的干重和叶片中的N含量，无论氮源或研究地点如何。