Effects of Sod Cultivation in Orchard on Distributions of Soil Aggregates and Soil Organic Carbon of Aggregates
生草栽培对果园土壤团聚体及其有机碳分布的影响

The effects of sod cultivation in orchard on distribution of organic carbon in soil aggregates were investigated, which located in Yuchi Village, Youxi Xian, Fujian Province. The results showed that compared with downslope and landings clean tillage orchards, the proportion of >0.25 mm water-stable aggregate (R0.25), mean weight diameter (MWD), and geometric mean diameter (GWD) of soil aggregate at 0-20 cm soil layer in sod cultivation orchard increased by 3.78%-5.90%, 16.82%-20.94%, 5.86%-50.31% and 3.81%-13.82%, 13.33%- 19.95%, 7.50%-60.63%, and the fractal dimension decreased by 1.54%-2.35% and 1.09%-9.64%, respectively. The sod cultivation could improve proportion of organic carbon storage in large aggregates (>2 mm) to total organic carbon at 0-20 cm soil layer. Therefore, the sod cultivation was beneficial to improve stability of soil aggregate, and could enhance the protection of organic carbon and carbon sink in soil.