【摘要】 以黑麦草为吸钾作物，对贵州５种主要成土母质发育的土壤进行了耗竭试验。并采用各种化学刚好方法研究上壤供钾能力。试验结果表明，侏罗系沙溪庙组紫红色泥质粉砂岩发育的紫色上供钾能力最强，其次为侏罗系自流井群黄色砂页岩发育的硅铝质黄壤和三叠系安顺组灰岩发育的石灰土，红色粘土发育的粘质黄壤和灰岩冲积物发育的潮泥最低。各种化学方法提取的钾和黑麦草吸收的钾量之间都有一定的相关性，其中以冷硝酸提取的钾量相关性最好。缓效钾量除和前６次吸钾量未达显著水平外，和以后各次吸钾量以及总吸钾量的相关性都很好，相关系数仅次于冷硝酸，醋酸铵提取的速效钾居第三。冷硝酸提取的钾量和黑麦草的相对产量有很好的相关性，达到极显著水平。因此，用冷硝酸提取的钾量可以预测钾肥的肥效。更多还原

【Abstract】 The K-supplying Powers of 5 soils developed from red clay,sandstone,limestone. purple siltstone and alluvium were studied. Pot experements were conducted by succesive croping rye grass and the soil K-content was also analysised by different chemical methods. The results from the experenments indicated that the K-supplying ability of soil developed from purple siltstone ranked the first,soils developed from limestone and sandstone ranked the next and soils developed from red clay and alluvium the lowest. The amounts of K -uptake by rye grass were closely correlated with cold nitrae acid soluble potassium.更多还原