Land Consolidation with Seedling Cultivation Could Decrease Soil Microbial PLFA Diversity

The impact of land consolidation on the soil microbial PLFA diversity is of great importance for understanding the effective arable land usage, improving agricultural ecological conditions and environment. In this study, we collected the soil samples (0-20 cm) in experimental plots with 0 (Z0), 1 (Z1a) and 4 (Z4a) years of land consolidation in the forest station of Ningbo City, Zhejiang Province, southeastern China. The results were analyzed using ANOVA for randomized block design. Compared with control (Z0), the soil pH value under Z1a treatment increased by 14.6%, soil organic carbon (SOC) content decreased by 65.4%, so did the PLFA contents and relative abundance of all the microbial PLFA diversity (P < 0.05), respectively. Meanwhile, for the Z1a treatment, the ratio of fungi to bacteria (F/B) significantly decreased by 35.9% (P < 0.05), while the ratio of Gram-positive bacteria to Gram-negative bacteria (G+/G-) signific antly increased by 56.1%. This was strongly related to the increased soil pH values and the decrease of SOC. The Shannon index (H) and evenness index (E) of soil microbial PLFA diversity were significantly decreased after land consolidation (P < 0.05). Compared to the Z1 treatment, the microbial PLFA diversity was improved slightly. Therefore, the land consolidation could significantly affect the composition of soil microbial PLFA diversity, and decrease the soil ecosystem stability.