不同施氮处理对夏玉米生长及其氮素吸收的影响

Influence of Different Rates of N-fertilizer on Growth and N-utilization in Summer Maize

采用田间小区试验,研究了不同施氮量(0,103.5,151.8,200.1,248.4 kg/hm2)对夏玉米产量及其不同生长期土壤剖面硝态氮含量变化的影响。结果表明,施氮处理的籽粒产量明显高于不施氮处理,且增产效果明显(增产3.7%～10.6%),以施氮248.4 kg/hm2处理的产量最高。从土壤硝态氮的含量来看,不同施氮处理表层0～40 cm土壤硝态氮含量较高,且随施氮量增加呈逐渐降低趋势;40～90 cm土壤硝态氮含量相对较低且波动较小,在大喇叭口期达到最低值;各生长期表层0～40 cm土壤硝态氮含量大体上施氮处理均高于不施氮处理,施氮能提高土壤硝态氮含量。表明在玉米生长发育期合理施氮是提高籽粒产量的一个重要因素,值得进一步研究氮肥供应期与玉米生长期的配合。

A field experiment was carried out to study the influence of nitrogen （N） fertilization on soil nitrate N （NO3-N） distribution, accumulation in soil profile, and grain yields, during the growth period of summer maize under different N application rates of 0, 103.5, 151.8, 200.1 and 248.4 kg/hm2. The results showed that grain yields under N application was significantly higher increasing 3.7% - 10.6%, than without N application, the situation reached the summit at 248.4 kg/hm2 of NFA. NO3-N in the 40 cm topsoil had a larger variation range than that in the 40 - 90 cm, this reached lowest value in large bell stage. During different growth periods, soil NO3-N without nitrogen fertilizer application （NFA） was less than that with NFA in 40 cm topsoil. Application N increased NO3-N content significantly. It is necessary to further study the optimal N application to get high grain yield during different growth periods.