Effects of close-to-nature transformation on content of soil organic phosphorus fractions in soil aggregates of Pinus massoniana plantations
Organic phosphorus(Po)is an important part of soil phosphorus reservoir.In order to investigate the effects of soil aggregate Po distribution properties in Pinus massoniana plantations after close-to-nature transformation,the pure P.massoniana plantations(PP)and P.massoniana-broad-leaved mixed plantations(CP)after close-to-nature transformation were investigated in southern subtropical China.Soil samples collected from 1-10 cm were screened into>2 mm,0.25-2 mm and<0.25 mm three-part aggregates using the dry-sieving method.The Po fraction,microbial biomass phosphorus(MBP)content and acid phosphatase(ACP)activity in the bulk soil and aggregates were measured to understand the distribution of the Po fraction and its drivers.The results were as follows:(1)Soil Po fractions changed in CP compared to PP,with highly recalcitrant organic phosphorus(HRO-P)and moderately labile organic phosphorus(MLO-P)significantly greater in the bulk soil and soil aggregates than in PP(P<0.05),while labile organic phosphorus(LO-P)and moderately recalcitrant organic phosphorus(MRO-P)were not significantly different in CP and PP.In addition,there was no consistent pattern of change in Po fractions in the bulk soil and soil aggregates between PP and CP.(2)The size of the proportion of each form of Po in PP was HRO-P>MRO-P>MLO-P>LO-P,while CP was HRO-P>MLO-P>MRO-P>LO-P.(3)The MBP content and ACP activity in CP were significantly greater than that of PP in the bulk soil and soil aggregates,and there was a tendency for the ACP activity to increase with the decrease in the size of aggregates.(4)Redundancy analysis revealed that soil available phosphorus(AP),soil aggregate mean weight diameter(MWD),MBP and total nitrogen(TN)were the main drivers of soil Po fractions.In conclusion,the close-to-nature transformation is beneficial to the accumulation and transformation of soil phosphorus in P.massoniana plantation.This study provides a theoretical reference for the improvement of soil quality and productivity in P.massoniana plantations.
万方数据
维普
