Effects of Utilization Methods on C, N, P Rate and Enzyme Activity of Artificial Grassland in Karst Desertification Area

Abstract

To investigate the effects of different utilization methods on the ratio characteristics of soil C, N, P and enzyme activities of grassland soil is of great significance for the sustainable utilization of grassland. In this study, the effects of different utilization methods on soil C, N, P rate and enzyme activities were investigated in artificial grasslands treated with grazing grassland (GG), mowing grassland (MG) and enclosed grassland (EG). The results showed that: (1) the contents of soil organic carbon (SOC), total phosphorus (TP) and ammonium nitrogen (NH4+-N) were EG > GG > MG; the contents of total nitrogen (TN), alkaline nitrogen (AN) and nitrate nitrogen (NO3−-N) were GG > EG > MG; the contents of available phosphorus (AP) and C:N were EG > MG > GG; the contents of C:P and N:P were MG > GG > EG; (2) β-1,4-Glucosidase (βG) and β-1,4-N-Acetylglucos-Aminidase (NAG) activities were GG > EG > MG, acid phosphatase (ACP) was EG > MG > GG, Leucine Aminopeptidase (LAP) was MG > EG > GG, C:NEEA and C:PEEA were GG > EG > MG, N:PEEA was GG > MG > EG; (3) redundancy analysis showed that AN (F = 4.90, p = 0.01) was an important driver of soil enzymes. We concluded that there were significant differences in soil C, N, P, enzyme activity and their ratio characteristics under different grassland uses. EG is closer to the standard ratio of global soil ecosystems. Therefore, reducing soil disturbance and optimizing fertilization are effective ways to improve soil enzyme activity and maintain good soil nutrient circulation.