EFFECTS OF SOD CULTIVATION ON STOICHIOMETRIC CHARACTERISTICS AND NUTRIENT CONTRIBUTION RATE OF SOIL AGGREGATES IN ROSA ROXBURGHII TRATT. ORCHARD

In order to determine the stoichiometric characteristics of soil aggregates and their relationship with soil nutrients, three sod cultivation treatments (intercropping of natural grass and Rosa roxburghii; intercropping of artificial grass and Rosa roxburghii; Rosa roxburghii monoculture) were set in Longli County, Guizhou Province, China.The aggregate distribution, ecological stoichiometry, and nutrient contribution rate of each particle sizes under different sod cultivation treatments were studied.Based on the results it can be concluded that both NG and AG treatments could enhance the number of macro aggregates.The contents of SOC, TN of aggregate under NG and AG treatments were higher than that of CK, while the contents of TP were lower than that of CK.The aggregate C/N of >0.5mm was NG>AG>CK.The C/P of aggregate was NG > AG > CK.The N/P of aggregate was NG>AG>CK.Under the AG treatment, 45% of the soil nutrients came from >5 mm and 5~2 mm aggregates.Under the CK treatment, 45% of the soil nutrients came from >5 mm and ＜0.25 mm aggregates.Sod cultivation was beneficial to increase the amount of macroaggregates and the contribution rate of macroaggregates to soil nutrients.The results provide the basis for regulating the soil fertility of Rosa roxburghii orchard.