缓/控释肥在土壤中的氮素释放特征及其对春玉米氮吸收的影响

为了探讨几种缓/控释肥在宁夏淡灰钙土上的氮素释放特性和生物学效应,寻求合适的缓/控释组合材料。通过盆栽试验,在氮磷钾等养分供应下研究了5个施肥处理对春玉米生长发育和氮素吸收利用的影响,同时探讨了几种缓/控释肥在土壤中的氮素释放规律。结果表明,相对不施氮处理,施用缓/控释肥可提高春玉米株高、地上部生物量和总生物量,同时也能显著促进地上部氮、根系氮和总氮吸收量,其氮肥利用率达33.9%~39.7%,较NPK平衡施肥(31.5%)提高了2.4%~8.2%。自研制缓/控释肥在土壤中的氮素释放天数在65天左右,释放高峰在第32天前后;而商品包膜尿素的氮素释放高峰在第17天前后,65天后依然有较高的氮素释放。因此,与商品包膜尿素相比,自研制缓/控释肥的氮素释放周期有待延长,但其对春玉米生育前期的氮素供应相对充足。

Effect of Slow/controlled Release Fertilizers on N uptake of Spring Maize and Their N Releasing Characteristics in Soil

In order to investigate the N releasing characteristics and biological effects of several slow/controlled release fertilizers in light sierozems in Ningxia, and find the suitable combination of materials for slow/controlled releasing. A pot experiment was conducted under the same N, P, K nutrients input to study the effect of five fertilizer treatments on the growth, N uptake and utilization of spring maize, and simultaneously investigate N releasing characteristics of these several slow/controlled release fertilizers in soil. The results indicated that the plant height, shoot biomass and total biomass of spring maize were more or less increased after applying slow/controlled release fertilizers in contrast to treatment no N fertilizer, and shoot N uptake, root N uptake and total N uptake were also significantly increased in treatments slow/controlled release fertilizers; N use efficiency was ranged from 33.9%-39.7% in these treatments of slow/controlled release fertilizers, which was increased by 2.4%-8.2% compared to treatment balance application of NPK (31.5%). There was about 65 days of N releasing in soil for independent development of slow/controlled releasing fertilizers, and the N releasing peak was happened before and after 32 days; however, N releasing peak was arose before and after 17 days for commodity coated urea, there was still high N releasing after 65 days in soil. Therefore, in contrast to commodity coated urea, the N releasing days should be extended in these independent development of slow/controlled release fertilizers, but there was enough N supplying from soil during the early growing period of spring maize.