Nutrient characteristics in rhizosphere of pure and mixed plantations of Manchurian walnut and Dahurian larch

Abstract

A comparison study was made for the characteristics of pH value, organic matter content, nutrient element N, P and K contents in rhizosphere soils of pure and mixed plantations of Manchurian walnut and Dahurian larch and in bulk soils. The results show that the pH values of rhizosphere soil for all the plantations except the pure walnut stand, which was slightly higher, were lower than those of bulk soils, while the organic matter contents in the rhizosphere soil for all the plantations except the mixed plantation, which was slightly lower, were higher than that in bulk soil. There exists a relative nitrogen accumulation in the rhizosphere and the extent to which the nitrogen accumulates is closely related to tree species and mixed pattern. As far as the total P and K contents are considered, there exists a deficient tendency in rhizosphere in comparison with bulk soil. The element N, P and K are all mobilized in the rhizosphere of the pure or mixed plantation, characterized by the higher contents of the available N, P and K in the rhizosphere. The available N content in the rhizosphere of the larch in mixed plantation was obviously higher than that of its pure plantation, whereas the available P and K contents in the rhizosphere of walnut in the mixed plantation, on the other hand, were significantly higher than those of its pure plantation.

Keywords

Rhizosphere soil / Bulk soil / Nutrient mobilization / Pure and mixed plantations / S714.8 / A