Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/3/2023
Publication Date: 6/19/2023
Citation: Chang, T., Feng, G.G., Adeli, A., Brooks, J.P., Jenkins, J.N. 2023. Soil health assessment for different tillage and cropping systems to determine sustainable mangement practices in a humid region. Soil & Tillage Research. 233:1-14. https://doi.org/10.1016/j.still.2023.105796.
Interpretive Summary: Soil is the foundation of agriculture, and plays a crucial role in food production. Soil degradation is accelerating due to poor land management. The results of soil health assessment can be used as an important tool to evaluate the dynamic changes in soil health and the rationality of agricultural management measures. Indicator selection is one of the most important steps in soil health assessment mainly because several physical, chemical and biological indicators are available and must be carefully chosen to represent the system. Poultry litter, cover crops, gypsum amendment, and irrigation are popular agricultural management practices, which affect soil health variously. This study was to use the data from five field experiments in Northeast Mississippi, USA to identify the soil indicators that are important for indicating soil health, to establish a minimum data set (MDS) for soil health assessment, and to compare the effects of agricultural management practices on soil health using the newly established MDS. This study selected 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). The elected chemical MDS was applied to all treatments of the five experiments. This MDS was applied to analyze the effects of treatments such as poultry litter on soil health, and the results showed that differences between treatments could be distinguished. Accordingly, it is suggested that this MDS could be used for future soil health evaluations in this region. However, the results of this study is based on the farmland in the high temperature and humidity area. Further consideration is required when applying to other climate types, planting systems and soil type. In addition, for future research, it is recommended to focus on the optimal selection of biological indicators.
Technical Abstract: Various soil indicators can be chosen for soil health assessment. The important indicators representing the overall soil health needs 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. Soil samples were collected from 0-15cm at five field experiments located in Caledonia, Starkville, Pontotoc, Verona, and Pontotoc. Measured soil physical, chemical and biological properties were normalized according to Standard Scoring Functions (SSF) in Soil Management Assessment Framework (SMAF). Three treatments (i.e., no-fertilized control, no-organic fertilizer and poultry litter) of the five experiments were selected to screen MDS by the combination of principal component analysis (PCA) and expert’s opinion (EO). A cluster analysis was also performed on the chemical indicators. The results showed that the correlation between the MDS and total data set (TDS) was high (R2=0.9350). 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). The selected chemical MDS was applied to all treatments of the five experiments, and the MDS and TDS fitted well (R2=0.8092). In summary, the MDS for soil health assessment was established in northeast Mississippi, which can provide fundamental guidance for researchers, growers, and stakeholders to evaluate soil health.