Enzyme activities as soil health indicators in relation to soil characteristics and crop production

Abstract

AbstractSoil enzyme activities are known for early indicators of soil health but have not been related to most soil properties and crop yields. We examined the relationships among activities of four soil enzymes (β‐glucosidase [BG], N‐acetyl‐β‐glucosaminidase [NAG], arylsulfatase [AST], and phosphomonoesterase [PME]), 62 soil properties, and mean crop yields in two long‐term (14‐ and 36‐yr‐old) dryland farming sites in the northern Great Plains, USA. Treatments were no‐till and till crop rotations with spring wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), pea (Pisum sativum L.), and fallow with and without N fertilization. Soil samples collected before farming operations in April 2019 were analyzed for physical, chemical, biological, and biochemical properties and mean crop yields were determined. The principal component analysis (PCA) showed that BG was associated to most soil physical, chemical, biological, and biochemical properties followed by NAG and PME at both sites. The AST was associated to limited number of soil properties. The BG related to mean crop yield across years in one site and NAG related to yields in both sites, but AS and PME were not related to yields. Because of the greater sensitivity to cropping systems and relationships with most soil properties and long‐term crop yields, BG and NAG activities may be considered as promising soil health indicators compared with other enzyme activities under dryland cropping systems in the northern Great Plains.