RESIDUAL EFFECTS OF NITROGEN FERTILIZER WITH POLYMER-COATED UREA IN A CORN CROP

ABSTRACT The use of nitrogenous fertilizer coated by polymers may reduce losses caused by volatilization, thus exposing this element to plants for a longer period of time. The objective of this work was to evaluate the residual effects of nitrogen in the form of conventional urea and urea coated by polymers in the production components and grain productivity of the first and second corn crops. The experiment was conducted in Selvíria - MS in a clay-type Oxisol during the corn crops of 2011/12 and 2012. The experiment was arranged as a randomized block design with four replications, with a factorial 4 x 4 treatment arrangement as follows: 4 doses of N (0, 40, 80 and 120 kg ha-1) and 4 forms of urea (conventional urea and urea coated by three different polymers). Treatments were applied at the time of corn sowing in the first season (2010/11) and second season (2011). The residual effects of nitrogen fertilization in the corn grown in the first crop season (2011/12) and the second crop season (2012) were then assessed. The polymer -coated urea did not differ compared to the conventional urea.

摘要
聚合物包膜氮肥（polymer-coated nitrogen fertilizer）可降低挥发造成的氮素损失，使该元素更长时间供给植物吸收利用。本研究旨在评估常规尿素（conventional urea）与聚合物包膜尿素（polymer-coated urea）中的氮素，对两季玉米的产量构成因素与籽粒产量的后效影响。试验于巴西南马托格罗索州塞尔维里亚（Selvíria - MS）的黏质氧化土（clay-type Oxisol）中开展，覆盖2011/12季与2012季玉米种植周期。试验采用随机区组设计（randomized block design），设置4次重复，采用4×4因子试验处理方案：4个施氮量水平（0、40、80、120 kg·ha⁻¹）与4种尿素类型，即常规尿素及3种不同聚合物包膜尿素。试验处理于第一季（2010/11季）与第二季（2011季）玉米播种时施用。随后评估氮肥在2011/12季与2012季种植玉米中的后效作用。聚合物包膜尿素与常规尿素的肥效无显著差异。