Location: Agricultural Systems ResearchTitle: Enzyme activities as soil health indicators in relation to soil characteristics and crop production
Submitted to: Agrosystems, Geosciences & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/11/2022
Publication Date: 8/9/2022
Citation: Sainju, U.M., Liptzin, D., Rana Dangi, S. 2022. Enzyme activities as soil health indicators in relation to soil characteristics and crop production. Agrosystems, Geosciences & Environment. 5(3). Article e20297. https://doi.org/10.1002/agg2.20297.
Interpretive Summary: Nutrient cycling enzymes are important for availability of nutrients to crops, but their roles as soil health indicators relating to soil properties and crop yields are less known. ARS scientists in Sidney, MT in collaboration with Soil Health Institute examined the relationships among soil carbon, nitrogen, phosphorus, and sulfur cycling enzyme activities, soil properties and mean crop yields in two long-term dryland field experiments. They reported that carbon and nitrogen cycling enzyme activities were sensitive to management practices and related to greater number of soil properties and also to crop yields than phosphorus and sulfur cycling enzyme activities. Producers can enhance carbon and nitrogen enzymes to enrich soil health, carbon sequestration, and nitrogen availability by using no tillage with continuous cropping in dryland cropping systems in the northern Great Plains.
Technical Abstract: Soil 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 (ß-glucosidase [BG], N-acetyl-ß-glucosaminidase [NAG], arylsulfatase [AS], and phosphomonoesterase [PME]), 64 soil properties, and mean crop yields of two long-term (14- and 36-y-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. Enzymes activities, except AS activity, were greater with no-till continuous cropping than conventional till crop-fallow. The BG correlated to 23-30 soil properties (8-13 weakly [r = 0.45-0.50], 9-11 strongly [r = 0.51-73], and 4-6 very strongly [r >0.73] related). The NAG correlated to 14-24 soil properties (4-6 weakly, 6 strongly, and 4-6 very strongly related). The AS and PME correlated less to 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 can be used as promising soil health indicators in dryland cropping systems in the semiarid climatic condition of the northern Great Plains, USA.