Mulching Effect on Soil Potassium Content of Poplar Plantation in Upland Area of Guizhou Province

The mixed mulching materials consisting of the cut waste of Imperata cylindrical var. major and Pteridium aquilinum var. latiuscukum was applied to poplar plantation in the upland area of Guizhou Province with 0, 2.5, 5.0 and 7.5 kg/m2 as the coverage intensity, and the dynamic change of soil potassium concentration in the poplar plantation soil was monitored. The results indicated that the available potassium content in the soil, the available potassium content in the rhizosphere soil, the R/S value of rhizosphere soil, and the potassium content inside the poplar trees all increased with the increment of mulching intensity, whereas the above discussed potassium contents decreased with time prolonging. Comparatively speaking, 7.5 kg/m2 of mulching intensity was more beneficial to the promotion of soil potassium content in the poplar plantation in the upland areas of Guizhou Province.