氮肥运筹与耕法对水稻籽粒增重过程的影响

应用数学模型Richards方程研究氮肥运筹与耕法对水稻籽粒增重过程的影响。结果表明:不同时期施用氮肥,以粒肥对籽粒增重过程的促进作用最大,而且影响的程度为源限制型品种大于库限制型品种,弱势粒大于强势粒;粒肥施用量(氮素)在0～103.5kg/ha范围内,随着施氮量的增加,籽粒起始灌浆势、最大灌浆速率、平均灌浆速率、活跃灌浆期和生长终值量增加,到达最大灌浆速率的时间缩短,灌浆速率曲线趋向左偏;采用浅、免耕,籽粒在灌浆前期生长比率较大,中、后期生长比率较小,常耕则相反。

EFFECTS OF NITROGEN MANAGEMENT AND TILLAGE METHODS ON GRAIN WEIGHT-INCREASING PROCESS IN RICE

The effects of nitrogen management and tillage methods on grain weight-increasing pro- cess were studied in this paper by using Richards Equation. The results showed that a. the grain fertilizer (applied at heading stage) had the greatest effect on promoting grain weight-increasing among the fertiliz- er applied at different stages, and the effect on the source-limited type varieties was greater than on that of the sink-limited ones, and on weak potential grains greater than on the strong potential ones; b.if the amount of grain fertilizer was between 0 and 103.5kg N/ha, with the increase of nitrogen applied, the ini- tial filling power, the maxium filling rate, the mean filling rate and the carrying capacity increased, and the vigorous filling period was longer and the time reaching the maxium filling rate was shortened, and the grain filling rate curves leaned left; and c. grains had a higher growth ratio at early filling phase than at medium or late filling phase if surface or zero tillage was practiced, and vice versa if conventional tillage.