秸秆还田条件下氮肥对玉米碳转运的影响

Effects of Nitrogen Fertilizer on Maize Carbon Translocation in the Condition of Straw Returning

试验采用盆栽方式,设置氮肥和秸秆还田2个因素,10次重复,4个施氮水平(N0、N1、N2、N3),施纯氮量分别为0、75、150、300 kg hm-2。试验结果表明,随着氮肥的施用量增加,无论有无秸秆添加,玉米光合碳量均呈现升高的趋势;在秸秆还田条件下,施氮量为300 kg hm-2时,光合碳量最大、产量最高;N0光合碳量对籽粒贡献率最大,JN1光合碳量对籽粒贡献率最小。对于玉米器官碳运转总量来说,JN2处理最大;随着施氮水平的继续提高,碳水化合物的转运相对减少,JN0的器官碳运转总量最小。当施氮量达到N2、N3水平时,无秸秆添加处理的玉米穗重分别为134.3 g、167.5 g,低于秸秆添加处理的154.5 g和176.7 g。玉米百粒重变化与穗重变化呈现出相似趋势。

The pot experiment was taken with two factors of nitrogen fertilizer and straw returning, ten replications, and four nitrogen levels （NO, N1, N2 and N3）in this study. Nitrogen amounts were 0, 75, 150, 300 kg hm-2. The results showed that, with the increasing of nitrogen amount, the carbon from photosynthesis always increased no matter straw returning to field or not. When nitrogen amount was 300 kg hm-2, the carbon from photosynthesis and yield were the most highest in the condition of straw returning. The contribution of the carbon from photosynthesis to grains reached the maximum value under NO. But it reached the minimum value under JN1. JN2 was the best for the carbon translocation in maize. The carbon translocation decreased with the further increasing of nitrogen amount. The value of carbon translocation under JN0 was minimum. When nitrogen amount were N2 and N3, ear weights without added straw into soil were 134.3 g and 167.5 g, respectively. But they were 154.5 g and176.7 g with added straw into soil, respectively. The variation of 100-grain weight had a similar trend to that of Ear weight.