通过盆栽试验研究了施氮水平和不同品种水稻对四川盆地 3种典型紫色水稻土 5种钾形态的影响以及各种土壤钾形态对水稻钾素营养的贡献。结果表明 ,4个紫色水稻土供钾能力均属中下水平 ,全钾含量为 1 2 9%～ 2 62 % ,其中矿物钾量平均占 96 82 % ,速效钾和非交换性钾仅平均占 0 62 %和 2 56% ,土壤供钾能力以中性紫色水稻土 >石灰性紫色水稻土 >酸性紫色水稻土。施氮 (N 0～ 150mg/kg)促进 4个紫色水稻土钾素的释放 ,提高水稻对非交换性钾和矿物钾的吸收利用 ,使矿物钾和非交换性钾的贡献占植株吸钾的 80 3% ,速效钾仅为 19 7%。中性紫色土供试 4个品种水稻的吸钾能力为开优 5号 >汕优 63>Ⅱ优 60 78>引佳 1号。施氮后4个品种水稻吸自非交换性钾和矿物钾量平均占植物吸钾量的 66 9% ,以施中氮 (N 150mg/kg)时植株吸钾量最高 ;而低氮或高氮水平都不利于植物对钾的吸收和土壤钾的释放 Pot experiments were conducted to study the effects of different levels of N fertilizer and five varieties of rice on five K forms in three typical purple paddy soils in Sichuan Basin and the contribution of various K forms to the K nutrition of rice. The results showed that all the four purple paddy soils had middle and lower levels of potassium supply, with the total potassium content ranging from 122% to 626%, of which the average amount of mineral potassium accounted for 96.82% of the total. Available potassium and non-exchangeable potassium accounted for only an average of 0 62% and 256%. The soil potassium supply capacity was neutral purple paddy soil> limestone purple paddy soil> acidic purple paddy soil. Nitrogen application (N 0 ~ 150 mg / kg) promoted the release of potassium in four purple paddy soils and increased the absorption and utilization of non-exchangeable potassium and mineral potassium in rice, making the contribution of mineral potassium and non-exchangeable potassium take up potassium 80 3%, available potassium is only 19 7%. Neutral purple soil for the four varieties of rice potassium absorption capacity of Kaiyou 5> Shanyou 63> Ⅱ You 60 78> cited good on the 1st. The potassium uptake by non-exchangeable potassium and mineral potassium in four varieties of rice after nitrogen application accounted for 66.9% of the total amount of potassium absorbed by plants, and the highest potassium uptake by N 150mg / kg, while the lowest nitrogen or high Nitrogen levels are not conducive to plant potassium absorption and soil potassium release