控释氮肥对洋葱-棉花套作体系产量及土壤氮含量的影响

2012—2013年在济宁市鱼台县,通过大田试验研究了速效氮肥和控释氮肥在0、100、200、300 kg·hm-2 4个氮素水平下对洋葱-棉花套作体系产量及土壤氮素含量变化的影响。结果表明:氮素用量200、300 kg·hm-2时,速效氮肥和控释氮肥处理棉花产量显著高于氮素用量100 kg·hm-2处理;氮素用量100、200 kg·hm-2时,控释氮肥棉花产量较速效氮肥处理分别显著增加17.3%和7.7%;施氮200 kg·hm-2的控释氮肥处理较氮素用量100 kg·hm-2的控释氮肥处理的籽棉显著增产14.5%,但与施氮300 kg·hm-2的控释氮肥处理相比差异不显著。控释氮肥较速效氮肥更能提高0~20 cm土层NO-3-N的含量,但对土壤中NH+4-N含量无显著影响。施用控释氮肥能够提高洋葱和棉花产量,施氮量为200 kg·hm-2的控释氮肥处理为本试验条件下的最优施肥处理。

Effects of Controlled-release Nitrogen Fertilizer on Yields and Soil Nitrogen in Onion-Cotton Intercropping System

Controlled-release nitrogen fertilizer(CRN) could meet plants' demands for nitrogen while reducing nitrogen losses and thus water pollution. A field experiment was conducted in Jining city, Shandong Province, from September 2012 to October 2013, to study the crop growth and soil nitrogen levels in onion and cotton intercropping system under common fertilizer(CN) and CRN at four nitrogen(N) rates of 0, 100, 200, and 300 kg·hm^-2. Results showed that the cotton yield increased with N applications. At 200 and 300 kg·hm^-2, the cotton yields were respectively 17.3% and 7.7% higher in CRN than in CN. In CRN treatments, the cotton yield at 200 kg·hm^-2 was 7.7% and 14.5% higher than that at CN(200 kg·hm^-2) and CRN(100 kg·hm^-2), respectively. However, no difference was found in the cotton yield between 200 kg·hm^-2 and 300 kg·hm^-2 CRN treatments. At 100, 200, and 300 kg·hm^-2, onion yields were respectively 19.6%, 2.6% and 6.7% higher in CRN than in CN. Soil NO₃^--N concentrations in 0~20 cm in CRN treatment were significantly lower than in CN treatment. Soil NH₄⁺-N contents were not affected by N treatments. These results suggest that 200 kg·hm^-2 of CRN would be an optimum fertilizer rate under the experimental condition.