Qi Zenglian, Dong Yuanjie, He Mingrong, Wang Maoying, Li Yu, Dai Xinglong
College of Resources and Environment, Shandong Agricultural University, Taian, China.
Agronomy College, Shandong Agricultural University, Taian, China.
Front Plant Sci. 2021 Dec 23;12:792262. doi: 10.3389/fpls.2021.792262. eCollection 2021.
Coated, slow/controlled release, or stabilized enhanced-efficiency nitrogen fertilizers (EENFs) are effective in improving nitrogen utilization efficiency (NUE) and crop yield. Better performance is expected from coated, stabilized EENFs where urease and nitrification inhibitors are treated in coated fertilizers. Firstly, five coated EENFs with different mass proportions of nature rubber (NR) in coating were prepared: CU0, CU1, CU2, CU3, CU4, and CU5 (0, 10, 20, 30, 40, and 50% of NR in coating). The controlled release performance of CU was tested by hydrostatic release test and the microstructure of controlled release urea, so as to screen the optimal addition ratio of NR (ER: NR = 7:3, CU3). Secondly, two coated, stabilized EENFs, CSU1 and CSU2, were prepared with natural rubber-modified epoxy resin (ER: NR = 7:3) as coating material. Seven treatments of different N fertilization were set up: CK (no N fertilization), urea, CU3, SU1, and SU2 (urease and nitrification inhibitors-treated urea fertilizers), CSU1 and CSU2 (urease and nitrification inhibitors-treated natural rubber-modified epoxy resin-coated urea fertilizers). Ammonia volatilization experiment and column leaching experiment showed that compared with conventional urea, NH volatilization loss was reduced by 20% and inorganic N leaching loss was reduced by 26% from CSU2, respectively. In the pot experiment, maize grain yield of 162.92 and 206.96 g/pot was achieved by CSU1 and CSU2, respectively, 41 and 79%, respectively, higher than that achieved by conventional urea. SUs treatments were more effective than conventional urea treatment in improving maize grain yield and NUE, but lower than in CSUs. The NUE, nitrogen fertilizer apparent utilization efficiency, partial factor productivity of applied N, and nitrogen utilization efficiency were 46, 30, 46, and 32%, respectively, higher in CSU1 and 58, 62, 58, and 29%, respectively, higher in CSU2 than in the conventional urea treatment. Compared with CSU1, CSU2 had better agronomic effectiveness with a higher NUE. It is recommended that urease and nitrification inhibitors be sandwiched between urea prill and the coating for preparation of novel, environmentally friendly coated, stabilized EENFs with high agronomic effectiveness, high NUE, and low N loss.
包膜、缓释/控释或稳定型增效氮肥（EENFs）在提高氮素利用效率（NUE）和作物产量方面具有显著效果。对于在包膜肥料中添加脲酶和硝化抑制剂的包膜稳定型EENFs，预期其表现更佳。首先，制备了五种包膜中天然橡胶（NR）质量比例不同的包膜EENFs：CU0、CU1、CU2、CU3、CU4和CU5（包膜中NR含量分别为0、10、20、30、40和50%）。通过静水释放试验和控释尿素的微观结构测试了CU的控释性能，以筛选NR的最佳添加比例（ER:NR = 7:3，CU3）。其次，以天然橡胶改性环氧树脂（ER:NR = 7:3）为包膜材料制备了两种包膜稳定型EENFs，CSU1和CSU2。设置了七种不同施氮处理：CK（不施氮）、尿素、CU3、SU1和SU2（添加脲酶和硝化抑制剂的尿素肥料）、CSU1和CSU2（添加脲酶和硝化抑制剂的天然橡胶改性环氧树脂包膜尿素肥料）。氨挥发试验和柱淋溶试验表明，与常规尿素相比，CSU2的氨挥发损失降低了20%，无机氮淋溶损失降低了26%。在盆栽试验中，CSU1和CSU2处理的玉米籽粒产量分别达到162.92和206.96 g/盆，分别比常规尿素处理高出41%和79%。SU处理在提高玉米籽粒产量和NUE方面比常规尿素处理更有效，但低于CSU处理。与常规尿素处理相比，CSU1的NUE、氮肥表观利用率、施氮偏生产力和氮素利用效率分别提高了46%、30%、46%和32%，CSU2分别提高了58%、62%、58%和29%。与CSU1相比，CSU2具有更好的农学效应和更高的NUE。建议将脲酶和硝化抑制剂夹在尿素颗粒和包膜之间，制备具有高农学效应、高NUE和低氮损失的新型环保包膜稳定型EENFs。
