中文摘要：

在湖北省江汉平原和鄂东南丘陵两个典型的生态区布置田间试验,研究K肥施用对水稻产量、经济效益及K素平衡的影响。结果表明,江汉平原生态区水稻产量有随施K量增加而逐渐升高的趋势,与不施K肥处理相比,施K（K2O）187.5kg/hm^2时增产量最高为3007kg/hm^2,纯增经济效益4136元/hm^2;鄂东南丘陵生态区施K效果显著,但各施K水平的差异不大,施K150kg/hm^2时水稻的增产量及纯增经济效益最高,分别为1495kg/hm^2和1852元/hm^2。江汉平原生态区各施K处理的K肥平均表观利用率为74.6%,低于鄂东南丘陵生态区的98.7%。研究结果还显示,两个生态区的农田K素在种植水稻后均呈负平衡,K肥施用可以缓解土壤K素的亏缺。

英文摘要：

Two field experiments of rice were conducted to study the effects of potassium （K） fertilizer on rice yield, economic profit, K utilization rate and on the field K balance in hilly ecoregion of southeastern Hubei and Jianghan Plain ecoregion. The results showed that K fertilizer increased obviously rice yield and economic profits in the two ecoregions, rice yield in Jianghan Plain increased with the increase of K utilization rate and the highest increased yield was 3007 kg/hm^2 with net economic profit of 4 136 Yuan/ hm^2 under 187.5 kg/hm^2 application of K2O. Rice yield in southeastern Hubei increased significantly with K fertilization but no significant differences among different rates of K fertilization, 150 kg/hm^2 application of K2O obtained the highest increased rice yield （1495 kg/hm^2） with net economic profit （1852Yuan/hm^2）. The average K utilization rate in Jianghan Plain was 74.6%, which was lower than that （98.7%） in hilly ecoregion of southeastern Hubei. The result also found the negative K balances in the two ecoregions after rice growing, which could be relieved by K fertilizer application.