Total
potassium(K), slowly available K and available K were determined in main
upland soils of Hunan province. A laboratery study on quantity-intensity (Q/I) relationships, release and fixation of soil K were conducted for eight representative upland soils from the Province
Potassium supplying capacity of the soils were evaluated. Response to K fertilizer using corn as indicator plant under greenhouse and field conditions were studied. Fonns of K were correlated with crop response to native and applied K.Research results indicated that purple
calcareous clayey soil derived from purplish shale and purple calcareous soil derived from lacustrine deposite contained dominantly clay
mineral with illite and mica, the content of K bearing mineral ranged from27.35%-29.28%,with upland soils derived from other parent material contained dominantly clay mineral with kaolinite and the content of K bearing mineral ranged only from 19.99%-23.25%.Total K, slowly available K and available K of main upland soils in Hunan province ranged from 1.44%-2.75%,160.4-475.ppm and 61.9 114.2ppm, respectively.K contents were slightly higher in Hunan upland
Soil than in paddy soil.The response of corm to K fertilizer on purple calcareous clayey soil and purple calcareous soil were not significant due to the high potassium content and higher potential buffer capacities, the response of corn to K fertilizer on yellow clayey soil was significant.However,the responses of corn to K fertilizer on other soils were very significant due to their low K content and the small potential buffer capacities of the soils.
More abstracts about the POTASSIUM SUPPLMNG CAPACITY OF MAIN UPLAND SOIL IN HUNAN PROVINCE