Soil management affects soil C and N stocks but not overall soil health

Abstract

Soil health describes a soil’s capacity to function as a vital ecosystem that sustains plants, animals, and humans. It can be assessed by measuring specific soil physical, chemical, and biological parameters combined into a soil health index (SHI). The objective of this study was to evaluate the effect of management, depth, and their interaction on soil health indicators. We evaluated long-term continuous tillage, horticultural crop rotation, which had an antecedent tropical pumpkin/bean rotation, and a no-till avocado orchard in a Cumulic Haplustolls at the Juana Díaz Agricultural Experiment Substation. Soil samples were taken at 0 to 15, 15 to 30, 30 to 50, 50 to 75, and 75 to 100 cm intervals using a hydraulic probe. Soil pH, electrical conductivity, bulk density, dry stable aggregates, mean weight diameter, tensile strength, carbon and nitrogen stocks, and water content were quantified. The data were analyzed in a multivariate ANOVA. Results were classified considering threshold values, and an SHI score was determined based on the simple additive method. Our findings show that the no-till avocado orchard had better soil physicochemical qualities, including higher C and N stocks, but this did not lead to an improved SHI score when compared with the continuous tillage crop rotation plot. Soil depth, management, and their interaction were significant effects in both management systems with a score of 0.55 on the SHI scale. These results imply that, although overall soil health is not affected, increased C concentration, no-till, and perennials have a favorable effect on SHI indicators in horticultural systems in the San Antón series.