Responses of soil microbial biomass, microbial entropy and soil-microorganism stoichiometry imbalance to different utilization patterns in the artificial grassland of karst desertification area

Different utilization patterns can alter the C, N, P cycles and their ecological stoichiometry characteristics in grassland soils. However, the effects of different utilization patterns on soil microbial biomass, microbial entropy and soil-microorganism stoichiometry imbalance of artificial grassland are not clear. So this study was took different utilization patterns of artificial grassland [i.e., grazing grassland (GG), mowing grassland (MG), enclosed grassland (EG)] as the research object to investigate responses of soil microbial biomass, microbial entropy and soil-microorganism stoichiometry imbalance to different utilization patterns in the karst rocky desertification control area. We found that the contents of microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) were highest in GG, and the content of microbial biomass phosphorus (MBP) was highest in EG. Soil microbial biomass entropy carbon (qMBC) and soil microbial biomass entropy nitrogen (qMBN) of GG and MG were higher than those of EG, but soil microbial biomass entropy phosphorus (qMBP) was opposite. C:N stoichiometry imbalance (C:N-imb) was EG > GG > MG, C:P stoichiometry imbalance (C:P-imb) was EG > MG > GG, N:P stoichiometry imbalance (N:P-imb) was MG > EG > GG. MBN was significantly positive correlated with C:N-imb and C:P-imb, MBC was significantly negative correlated with C:P-imb, MBP was significantly negative correlated with N:P-imb. The redundancy analysis (RDA) results showed that N:P-imb (p = 0.014), C:N-imb (p = 0.014), and C:P in the soil (C:P-soil, p = 0.028) had the most significant effect on microbial entropy. EG had a significant effect on soil microbial biomass and microbial entropy. The results of this study can directly or indirectly reflect the grassland soil quality under different utilization patterns in the karst rocky desertification area, which has a certain reference value for the degraded ecosystem restoration.

Automated summary

Different utilization patterns can affect the soil microbial biomass, microbial entropy, and soil-microorganism stoichiometry imbalance in artificial grassland. This study investigated the responses of soil microbial biomass, microbial entropy, and soil-microorganism stoichiometry imbalance to different utilization patterns in a karst rocky desertification control area. The results showed that grazing grassland had the highest microbial biomass carbon and microbial biomass nitrogen, while enclosed grassland had the highest microbial biomass phosphorus. The study also found that different utilization patterns affected the stoichiometry imbalance in the grassland soil. C:N-imb, C:P-imb, and C:P in the soil had the most significant effect on microbial entropy.