Comparative study on microbial community structure across orchard soil, cropland soil, and unused soil

Abstract

We examined the effects of three different soil conditions (orchard soil, cropland soil, unused soil) on the functional diversity of soil microbial communities. The results first showed that orchard and cropland land use significantly changed the distribution and diversity of soil microbes, particularly at surface soil layers. The richness index (S) and Shannon diversity index (H) of orchard soil microbes were significantly higher than the indices of the cropland and unused soil treatments in the 0–10 cm soil layer, while the S and H indices of cropland soil microbes were the highest in 10–20 cm soil layers. Additionally, the Simpson dominance index of cropland soil microbial communities was the highest across all soil layers. Next, we found that carbon source differences in soil layers under the three land use conditions can mainly be attributed to their carbohydrate and polymer composition, indicating that they are the primary cause of the functional differences in microbial communities under different land uses. In conclusion, orchard and cropland soil probably affected microbial distribution and functional diversity due to differences in vegetation cover, cultivation, and management measures.