Agronomy (Jul 2023)

Response of Soil Absolute and Specific Enzyme Activities to Long-Term Application of Organic Fertilizer to Solonetz in Northeast China

  • Danyang Liu,
  • Andi Feng,
  • Senmiao Li,
  • Bo Song,
  • Yujie He,
  • Yunhao Lv,
  • Jingmei Luo,
  • Yang Liu,
  • Xianfa Ma,
  • Xinyang Li

DOI
https://doi.org/10.3390/agronomy13081987
Journal volume & issue
Vol. 13, no. 8
p. 1987

Abstract

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Soil organic carbon (SOC) and microbial biomass carbon (MBC) are highly correlated with enzyme activities. Specific enzyme activities can exclude the autocorrelation between enzyme activity and SOC and MBC. However, the responses of absolute and specific enzyme activities to saline–alkali properties remains unclear. In this study, the absolute and specific enzyme activities of cellobiose hydrolase, β-glucosidase, arylsulfatase, alkaline phosphatase, and urease were measured in soils with 10, 15, 18, 21, and 26 years of organic fertilizer application in contrast to soils without organic fertilizer application. The results showed that long-term organic fertilizer application led to significantly increased in the absolute and specific enzyme activity and decrease in pH, electrical conductivity (EC), exchangeable sodium percentage (ESP), as well as sodium adsorption ratio (SAR5:1). In the structural equation model (SEM), the EC extremely limited the geometric mean of specific enzyme activity per unit of MBC (MBC-GMSEA) (path coefficient, −0.84, p 5:1 were higher than between the absolute soil enzyme activity and pH, EC, ESP, and SAR5:1. Of the parameters tested, EA/MBC was a more sensitive index to reflect the improvement effect of organic fertilizer on soils and evaluate the saline–alkali barrier.

Keywords