Abstract

A field experiment consisted of two types of N fertilizer, controlled release urea (CRU) and normal urea (U), in combination with three SAP application rates (0, 45 and 90 kg ha⁻¹) in a split-plot design was conducted in 2018 and 2019. The successive release of N from polymer-coated urea corresponded well to the N requirements of maize growth. The NO₃ ⁻-N and NH₄ ⁺-N contents in the 0-20 cm soil layer were enhanced at the jointing and twelve leaf collar stages, and the leaching of soil NO₃ ⁻-N was reduced by using CRU. The application of superabsorbent polymer (SAP) increased soil water stock, decreased evapotranspiration and enhanced water use efficiency (WUE) and nitrogen use efficiency (NUE). The combined application of CRU and 90 kg ha⁻¹ SAP achieved maximal maize yield, WUE, NUE, and net income values that were 0.8–32.9%, 0.2–37.4%, 4.1–13.1%, and 2.8–42.1%, respectively, higher than those of other treatments. These results demonstrate that the co-application of CRU and 90 kg ha⁻¹ SAP is an effective practice that enhances the water and N utilization of maize and could potentially have wide application on the North China Plain.

摘要

在分块设计中，进行了由两种类型的氮肥，控释尿素（CRU）和普通尿素（U）结合三种SAP施用量（0、45和90 kg ha ^-1）组成的田间试验。在2018年和2019年。从聚合物包膜尿素中连续释放氮与玉米生长对氮的需求非常吻合。的NO ₃ ^- -N和NH _4项 ⁺中的0-20厘米土壤层-N内容物在拔节和12叶颈阶段提高，土壤浸出NO ₃ ^--N通过使用CRU减少。使用超吸收性聚合物（SAP）可增加土壤蓄水量，减少蒸散量，并提高水分利用效率（WUE）和氮利用效率（NUE）。CRU和90 kg ha ^-1 SAP的组合施用可实现最大玉米产量，WUE，NUE和净收入，分别为0.8–32.9％，0.2–37.4％，4.1–13.1％和2.8–42.1％。高于其他治疗方法。这些结果表明，CRU和90 kg ha ^-1 SAP的联合施用是提高玉米对水和氮的利用率的有效实践，并有可能在华北平原广泛应用。