[Effect of land consolidation on soil microbial community diversity.]

Land consolidation has become a main means of achieving the intensive use of land resources, which ensures the dynamic equilibrium and requisition-compensation balance of the total cultivated land in China. However, the intensive disturbance during the land consolidation may affect the soil quality. In order to investigate the effect of land consolidation on soil microbial diversity, we studied the changes of soil microbial community diversity after 1-year and 4-year land conso-lidation by using PLFA method. The results indicated that compared with no consolidation (Z0), for land consolidation after 1a (Z1a), the soil pH value increased by 14.6%, the soil organic carbon content decreased by 65.4%, the phospholipid fatty acids content and relative abundance of all the microflora decreased significantly (P<0.05) by 43.4%-63.7% and 25.2%-53.9%, respectively, and the ratio of fungi/bacteria (F/B) decreased significantly by 35.9% (P<0.05), while the ratio of Gram-positive bacteria/Gram-negative bacteria (G⁺/G^-) increased significantly by 56.1%. These were significantly related to the increased pH value and the decrease of organic carbon content. The Shannon index and evenness index (E) of soil microbial diversity were significantly decreased, with significant differences observed among Z0 and Z1a, Z4a. After 4-year land consolidation, the indices characterizing soil microbial community diversity were improved compared with those after 1-year land consolidation. In summary, the land consolidation could significantly affect the composition of soil microbial communities, and decrease the stability of the soil ecosystem.