不同水稻品种对钾的吸收及其对钾肥的反应

测定了９个水稻品种在０．１ｍｍｏｌ／ＬＫ２ＳＯ４＋０．２ｍｍｏｌ／ＬＣａＳＯ４溶液中吸收２小时和４小时的Ｋ＾＋浓度和ＰＨ值的变化。结果表明溶液的ＰＨ变化与Ｋ＾＋浓度变化呈极显著的正相关，这为建立快速简便地筛选高吸钾速率水稻品种的方法提供了基础。幼苗耗竭试验表明，水稻利用土壤中的钾大部分来自非交换性钾源。各品种的吸钾总量与来自非交换性钾及１ｍｏｌ／ＬＨＮＯ３不能撮的钾和矿物钾均有极显著的相关性，这可

DIFFERENCES OF RICE VARIETIES IN POTASSIUM UPTAKE AND RESPONSE TO POTASSI-UM APPLICATION

pH changes and K uptake by nine rice varieties in a solution containing 0.1 mmol/L K₂SO₄ plus 0.2 mmol/L CaSO₄ were measured in the study. Changes of pH and K concentration were strongly correlated over 2 and 4 hours, which could be the basis for the establishment of a rapid and simple method for screening, selecting rice varieties with a high rate of K uptake. Based on the total K uptake by rice in a successive cropping experiment, the greater part of its K requirement was obtained from non-exchangeable sources. Total K uptake by rice varieties was significantly correlated with non-exchangeable potassium and potassium in extractable with 1 mol/L HNO₃ and mineral potassium, which could be used as criteria for screening high potassium-absorbing rice varieties. Yield responses of rice varieties to K application were studied as well.