氮肥运筹对免耕水稻根系生长、根际土壤特性及产量的影响

为探索氮肥运筹对免耕条件下水稻根系生长以及对根际土壤特性、产量的影响，以金优253为材料进行试验。结果表明：平衡施肥显著提高单株根系干重、根长、单株生物量、根半径、单株根表面积、根长密度及根系活力，实收单产高于重穗肥和重基肥处理，且与重基肥差异达95％的显著水平，主要是有效穗数、结实率的增加。平衡施肥显著提高0~10 cm土层的0~2 mm根际土壤有机质、碱解氮含量及脲酶、蔗糖酶活性。因此平衡施肥能明显促进免耕水稻根系生长和有效穗数的增加，对提高水稻产量具有促进作用。

Effect of different nitrogen application modes on root growth,rhizosphere soil characteristics and rice yield under no-tillage

The effect of nitrogen application modes on root growth,rhizosphere soil characteristics and rice yield under no-tillage and cast transplanting rice was studied. The results showed that balanced fertilization made obvious influence on no-tillage and cast transplanting rice root growth,and physiology. The rice shoot dry weight and biomass per plant,root number,root density,root activity of balanced fertilization were higher than other treatments,the differences were significant in rice later growth. However,there were no significant differences in root length. Balanced fertilization increased spike lets per panicle and seed set. Balanced fertilization significantly increased 0-10 cm soil layers organic,available nitrogen and urease activity of 0-2 mm rhizosphere soil in rice late growth. Therefore,it can been concluded that balanced fertilization acquired higher grain yield by improving rhizosphere soil,promoting root growth and increasing effective panicles.