高产土壤条件下双季杂交稻的施钾效应

EFFECTS OF POTASSIUM FERTILIZATION ON DOUBLECROPPING HYBRID RICE IN HIGHYIELD SOIL

为研究高产土壤条件下双季杂交稻不同施钾水平的效应，以肥力水平高，供钾能力较好的冲积性水稻土为供试土壤，以杂交水稻Ｖ４０２（早稻）和Ｖ４６（晚稻）为供试作物，进行田间小区试验．结果表明，早稻生育期间土壤供钾能力比晚稻生育期间强，施钾对早稻稻谷产量和地上部分干物质总量均无正效应；而晚稻施钾对稻谷产量和地上部分干物质总量均有良好效果，二者均随施钾量提高而提高．但在施钾显著增产的范围内，施钾的效应系数仍不大，这是供钾能力较好的高产水稻土上双季稻施钾效应特性之一．各施肥处理的稻谷产量均是晚稻高于早稻，在过高的施钾量条件下，早稻成熟期体内钾素有严重的淋失现象，有待进一步研究．

To study the effect of various application rates of K fertilizer in high yield soil where double cropping hybrid rice is planted,a plot experiment is conducted in K rich alluvial paddy soil. The experimental crop is V402 rice (early rice) and V46 (late rice). The results show that the soil′s K fertilizer supplying ability is stronger at early rice′s growth period than at late rice′s growth period. The application of K fertilizer has no positive effect on both the early rice′s yield and the total production of above ground dry matter. While the application of K fertilizer has positive effect on the yield and the total above ground dry matter. The yield and dry matter increase with the increasing application of K fertilizer. But in the range which the application of K fertilizer increases yield significantly,the effect coefficient of K fertilizer′s application is small. This is one of the characteristics of K fertilizer′s application effect on the highyield rice soil where the supplying ability of K fertilizer is strong. The early rice yields are more than the late rice when fertilizer is applied. And there is a serious loss of K in early rice during its maturing period when K fertilizer is over applied. This phenomenon is worth a further study.