Study On Soil K-supplying Potential And Potassium Application Effect On Red Soil And Yellow Cinnamon Soil Under Different Planting Patterns

The K dynamic change in the rhizosphere soil was studied in red soil and yellow cinnamon soil by continuous culturing with 3-compartment-pot under there different planting patterns,and to investigate the effect of continuous cultivation,X-ray diffraction and Quantity-Intensity(Q/I) relationship were adopt.The results demonstrated:The biomass of exhaustion treatment rapidly decreased,and soil potassium supply level fall suddenly to the lowest value,the biomass and the k absored of NPK treament are lager than NP treament,during the process of cultivation,compared to NP treament, the contents of available K and slow-available K in the rhizosphere soil of the two soils are lager than the non-rhizosphere soil.The change rates of the contents of available K and slow-available K of red soil are lager than yellow-cinnamon-soil' in both NP treatment and NPK treatment,But the content of total K of the two soil had changed littlely.The impact of soil K depletion of the two soils by the there different planting-patterns observed in the following order:continuous rice cultivation＞continuous rice-ryegrass rotation＞continuous ryegrass cultivation.From the data of X-ray diffraction study,without K fertilization,there are significant changes in the K-bearing mineralogy at the peak of d₀₀₁ in the rhizosphere soil form nonrhizosphere soil;whereas slightly difference at the peak of hydromica,chlorite and vermiculite,and mixed-layered mica-smectite component after 11-Continuous cultivation.After continuous cultivation,The value of K⁺ equilibrium activity ratio(AR₀),the value of potassium buffering capacity(PBC) decease a litter in the NP treament compare with the beginning of the two soils'.Whereas increased a litter in the NPK treament.The change rates of these values of red soil are lager than yellow cinnamon soil.