运用玉米苗对褐土、潮土不同层次土壤进行了钾素生物耗竭试验 ,发现 :当土壤有效钾素趋向匮乏时 ,首先受到影响的是玉米苗的干生物产量 ,其次是植株总吸钾量 ,再其次才是植株含钾量 ;矿物钾对植株吸钾是有贡献的 ,但其贡献率因土壤不同而有很大的差异 ,褐土矿物钾的贡献率比潮土的要大 ;交换性钾、非交换性钾的生物有效性因土类的不同而存在明显差异 ,总的说来 ,潮土较褐土能提供较多的钾素 ;土壤供钾性能随深度增大而减弱 Maize seedlings of different levels of cinnamon soil, tidal soil bio-depletion tests carried out potassium found that: when soil available potassium deficiency, the first to be affected is the dry biomass of corn seedlings, followed by the total amount of potassium plant , Followed by the potassium content of plants; Mineral potassium contributes to the potassium uptake by plants, but its contribution rate varies greatly from soil to soil, and potassium contribution from cinnamon minerals is larger than that from the fluvo- The bioavailability of potassium and non-exchangeable potassium are obviously different due to the difference of soil types. Generally speaking, more potassium can be supplied by the soil than the brown soil; and the potassium supply of the soil is weakened with the increase of soil depth