红壤稻田钾肥施用量对超级稻生长及产量的影响

 以超高产水稻中浙优1号、甬优9号为材料，研究土壤不同钾素水平(50 mg/kg、90 mg/kg)及钾肥用量(0、75、150、225 kg/hm2氯化钾)对水稻生长和产量的影响。土壤不同钾素水平对穗数、成穗率、每穗粒数、着粒密度、株高、叶片叶绿素含量（SPAD值）和光合速率有显著影响，差异达显著水平；不同时期施用钾肥对产量的贡献依次为：基肥>分蘖肥>穗肥，产量差异达到3%~10%；随着施钾量增加植株高度明显增加，中浙优1号上表现更为明显，且随着施钾量增加，茎秆加粗，特别是基部节间粗度增加尤为明显。施钾与不施钾相比，两个品种产量分别增加5.6%和8.8%，但产量增加并不与施钾量成正比，不同施钾水平间产量差异不显著。

Effects of Potassium Fertilizer Rate on Growth and Yield Formation of Super High Yielding Rice in Red Paddy Soil

A pot and a field experiment were conducted to observe the growth and yield characteristics of super high yielding rice varieties， Zhongzheyou 1 and Yongyou 9 in red paddy soils (K levels: 50 and 90 mg/kg) at various potassium fertilizer rates (KCl: 0, 75, 150 and 225 kg/hm2 )． The soil K content had significant effect on the panicle number, pencentage of productive culms, grain number per panicle, grain density, plant height, leaf chlorophyll content(SPAD value), leaf photosynthetic rate and grain yield． The order of the contributions to output for potassium fertilizer applicated at different stages was as follows: basal fertilizer >fertilizer applied 5 days after transplanting>fertilizer applied at the exsertion of the third leaf from the top, with grain yield difference from 3% to 10%. The plant height significantly increased with increasing potassium application rate, especially for Zhongzheyou 1. At the same time, the culm thickness increased, especially the basal culm internode. The grain yield of the two varieties increased by 5.6% and 8.8% with potassium application, and no significant difference was found among different potassium application levels.