不同水稻品种对钾的吸收及其对钾肥的反应

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

测定了９个水稻品种在０．１ｍｍｏｌ／ＬＫ＿２ＳＯ＿４＋０．２ｍｍｏｌ／ＬＣａＳＯ＿４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／ＬＨＮＯ＿３不能提取的钾和矿物钾均有极显著的相关性，这可作为筛选吸钾能力强的水稻品种的指标。此外，还研究了不同品种对钾肥的反应。

H changes and K uptake by nine rice varieties in a solution containing 0.1mmol/L K_2SO_4 plus 0.2 mmol/L CaSO_4 were measured in the study. Changes of pHand K concentration were strongly correlated over 2 and 4 hours, which could bethe basis for the establishment of a rapid and simple method for screening, selectingrice varieties with a high rate of K uptake. Based on the total K uptake by rice ina successive cropping experiment,the greater part of its K requirement was obtainedfrom non-exchangeable sources.Total K uptake by rice varieties was significantly co-rrelated with non-exchangeable potassium and potassium in extractable with 1 mol/LHNO_3 and mineral potassium,which could be used as criteria for screening highpotassium-absorbing rice varieties.Yield responses of rice varieties to K applicationwere studied as well.