大豆生育期土壤硝态氮的动态变化

Dynamic change of nitrate-N at the growth stage of soybean

试验研究了不同施肥条件下,大豆生育期内的土壤硝态氮含量动态变化。结果表明,从花期到鼓粒期是大豆吸氮高峰期,鼓粒期后大豆几乎不再吸收氮素。大豆生育期土壤剖面累积NO3--N量随施氮量的增加而增加;但施氮量在67.5kg·hm-2以下不会引起下层土壤NO3--N含量升高,只有施氮量高于67.5kg·hm-2时会导致120cm土层中NO3--N含量升高。

This paper studied the change period of soybean. The results showed that the of NO3^- -N in soil profile of different fertilizer treatments at growth largest absorption period of soybean appeared from florescence to seed filling stage. The content of cumulated NO3^- -N in soil profile at growth period of soybean increased with the improvement of nitrogenous fertilizer. However, when the quantity of nitrogen fertilizer exceeded 67.5 kg·hm^-2, applying nitrogen would cause the increase of NO3^- -N in 120 cm soil lager.