不同施肥处理对作物产量及土壤中硝态氮累积的影响

Effects of different fertilizers on crop yields and nitrate accumulation

通过4a定位试验研究了小麦-玉米轮作制度下不同施肥处理对作物产量及硝态氮(NO3--N)在土壤中累积和分布的影响。结果表明:长期大量施用氮肥,会造成土壤NO3--N的累积,且土体NO3--N的含量随施氮量的增加呈直线上升趋势;在土壤空间差异不显著的情况下,NO3--N在400cm土体中的分布呈一定的规律性,分别在60cm和200cm左右存在累积峰;配合施用磷肥、钾肥可以降低土壤剖面NO3--N的含量,尤其是钾肥可显著降低土壤上层NO3--N的含量,但作物无法吸收的NO3--N却有整体下移的趋势。提出华北山前平原高水肥投入地区NPK合理施用量为:N肥200kg/(hm2·a),P肥32.5kg/(hm2·a),K肥150kg/(hm2·a)。

Based on the 4year filed experiment, the effects of different fertilizers on distribution and accumulation of NO3--N, and the yields of crops have been studied. The results showed that the longperiod nitrogen application with large amount caused NO3--N to accumulate in the soil profile, and the amount of NO3--N accumulated in the soil profile was increased with rate of N fertilizer application increased. There were 2 peaks of NO3--N accumulation in soil profile, one in 60~80 cm and another in 180~200 cm, but the position and value of accumulation peak changed with the soil texture in different layers. The combined application of P and K reduced the accumulation of NO3--N,especially the application of K reduced the accumulation in root zone, but the NO3--N left in the soil tended to move to the deeper profile. The amount of N, P and K application suitable to the plain areas nearing Taihang Mountain was advanced according to the test, i.e., N 200 kg/(hm\+2·a), P 32.5 kg/(hm\+2·a) and K 150 kg/(hm\+2·a).\;