Bruna Emanuele Schiebelbein a , Victória Santos Souza a , Maurício Roberto Cherubin a b
- a“Luiz de Queiroz” College of Agriculture, University of São Paulo (ESALQ/USP), Piracicaba, SP, Brazil
- bCenter for Carbon Research in Tropical Agriculture (CCARBON) – University of São Paulo, Piracicaba, SP, Brazil
Highlights
- SOHMA KIT® is a new on-farm framework for assessing soil health.
- SOHMA KIT® evaluates physical, chemical, and biological soil indicators.
- SOHMA KIT® consists of seven field-based, time- and cost-effective methods.
- The indicators have been validated for reliability, sensitivity and practicality for the Brazilian savannah.
- Cover crop improved the Soil Health Index by up to 35 % detected by SOHMA KIT®.
Abstract
Soil health is a foundation for long-term soil multifunctionality, sustaining crop yields and enhancing crop resilience to climate change. Nevertheless, soil health assessments are often complex, costly and time-consuming, which acts as a barrier to farmers adopting them. Thus, we hypothesized that a simplified, on-farm approach to evaluate soil health, composed by key indicators, could effectively detect changes in soil health across different land management systems. This study aimed to (i) validate the Soil Health and Management Assessment Kit (SOHMA KIT®) as a reliable tool for on-farm soil health assessment, (ii) compare its performance with standard laboratory methods, and (iii) assess its sensitivity for detecting soil health improvements induced by cover crops. The validation study was conducted in two long-term field experiments in the Brazilian savanna (Cerrado biome), where different cover crop systems were evaluated. After extensive work involving literature review, selection and development of methods, the SOHMA KIT® was created. The SOHMA KIT® integrates seven soil health indicators from physical (infiltration, aggregate stability, Visual Evaluation of Soil Structure – VESS), chemical (pH), and biological (catalase enzyme, macrofauna, biogenic aggregates) components into a Soil Health Index (SHI). In the validation tests, results showed that the SHI increased around 35 % in diversified cropping systems. Strong correlations between SOHMA KIT® and standard methods were observed for key indicators (e.g., infiltration: r = 0.71, aggregate stability: r = 0.40, pH: r = 0.88). Despite its portability and cost-effectiveness, the toolkit has some limitations, such as it is recommended that users have a basic training for assessing visual indicators, and the assessment is focused only on topsoil layers. However, the SOHMA KIT® is user-friendly and scalable, being a valuable tool for on-farm decision-making, regenerative agriculture, and large-scale soil health monitoring.
Keywords
Soil quality, Regenerative agriculture, Cover crops, Field-based soil evaluation, Visual soil assessment
