钾肥施用量对寒地粳稻不同穗位籽粒灌浆过程和产量的影响

Effects of potassium fertilizer on the grain filling and yield of japonica rice at different panicle positions in cold region

以东农425、东农427和松粳6号为材料,设7个钾素水平,即K2O施用量为：K0（0 kg·hm-2）、K1（25 kg·hm-2）、K2（50 kg·hm-2）、K3（75 kg·hm-2）、K4（100 kg·hm-2）、K5（125 kg·hm-2）和K6（150 kg·hm-2）。研究了钾肥用量对寒地粳稻不同穗位籽粒灌浆过程和产量的影响。结果表明：适宜的钾肥施用量为75~100 kg·hm-2。品种间灌浆过程的变化规律相似,穗位间灌浆过程差异较大。各穗位的千粒重、结实率与最终的产量相关性显著。钾肥施用量可以调节不同穗位籽粒的灌浆强度,在最适钾肥施用量下,上部穗位籽粒起始生长势（R0）与中、下部穗位籽粒R0的平均差异缩小到0.089,而平均生长速率（GRmean）在K6处理下与中、下部穗位籽粒GRmean的平均差异缩小到0.016 g·d-1;适宜的钾肥施用量也明显提高了不同穗位籽粒中、后期灌浆的产量贡献率,最终使不同穗位的产量均衡,并达到高产。

Three japonica rice varieties,Dongnong 425,Dongnong 427 and Songjing No. 6,were studied by field experiments with K2 O rates as K0（ 0 kg·hm- 2）,K1（ 25 kg·hm- 2）,K2（ 50 kg·hm- 2）,K3（ 75 kg·hm- 2）,K4（ 100kg·hm- 2）,K5（ 125 kg·hm- 2） and K6（ 150 kg·hm- 2）,to explore the effect of potassium fertilizer application rates on grain filling and yield of rice with different ear grains of japonica rice in cold region. The results showed that the appropriate amount of applied potassium fertilizer was 75 ~ 100 kg·hm- 2. Variations of filling process were similar among different varieties and different among ear heights. Grain weight and seed setting rate was significantly correlated with final yield. Potash fertilizer adjusted the intensity of the filling process at different ear height. Under the condition of optimum potash fertilizer,the average difference of initial growth potential R0 between upper and the middle and lower ear grain reduced to 0. 089. In K6,the average difference of average growth rate GRmeanbetween upper and the middle and lower ear grain reduced to 0. 016g· d- 1. The appropriate amount of potash fertilizer significantly made greater contribution to the yield of different ear height grains during mid-and late filling process,balanced the yield of different ear height grains,and then improved the yield.