Soil health assessment for different tillage and cropping systems to determine sustainable management practices in a humid region

Abstract

Various soil indicators can be chosen for soil health assessment. The important indicators representing overall soil health need to be carefully selected to reduce the cost and time involved in sampling and testing, which can be achieved by establishing a minimum data set (MDS). The objective of this paper was to identify the indicators that are important for assessing soil health in northeast Mississippi and establish an MDS. Values for chemical, physical and biological indicators obtained from three treatments (no-fertilized control, no-organic fertilizer and poultry litter) in five different field experiments were used to screen MDS. The methodology followed a combination of principal component analysis (PCA), cluster analysis and expert’s opinion (EO) method. Results showed that the correlation between the MDS and total data set (TDS) was high (R2 =0.94). The chosen MDS included four chemical indicators (pH, organic carbon, total nitrogen and Mehlich-3 phosphorus), three physical indicators (bulk density, water-stable aggregate stability, available water capacity), and two soil biological indicators (dehydrogenase activity, heterotrophic plate count). When the selected chemical MDS was applied to all treatments of the five experiments, the MDS and TDS data fitted well (R2 =0.81), indicating that the soil indicators included in the MDS were the most important for soil health in this study. In conclusion, an MDS for soil health assessment was established for the experiments in northeast Mississippi. The results can provide fundamental guidance for researchers, growers, and stakeholders to evaluate soil health and optimize soil management.