Time Matters: A Short-Term Longitudinal Analysis of Conservation Agriculture and Its Impact on Soil Health

Conservation agriculture is seen as a potential solution to modern farming challenges. This paper elucidates its immediate impact by investigating the short-term dynamics of soil health, including the biological constituents, following the implementation of conservation agriculture. We hypothesised that implementing conservation agriculture would lead to changes in soil health. However, these changes will vary across the physical, chemical, and biological properties of the soil, given that each of these components is likely differently influenced by conservation agriculture. The study site was a multi-year trial in Ottosdal (South Africa) with different crop production systems, including maize monoculture, conservation agriculture (rotation of maize, sunflower, and cover crops), and an uncultivated grassland, which served as a natural reference system. Appropriate statistical methods were used to analyse soil health parameters and their interactions from samples collected during the three consecutive summer growing seasons. The study revealed significant soil health dynamics between the cultivated and uncultivated systems. Total available P, organic matter content, and microbial biomass were key indicators of soil health over the 3 years. Crop sequence influenced these dynamics, while a shift from abiotic to biotic factors was observed as primary system differentiators. Notably, crop rotation and soil structure significantly influenced soil microbial communities. These findings provide valuable insights into the interactions between soils and biota and the resulting effects on soil health dynamics. However, further research is required to fully elucidate the mechanisms involved and optimise sustainable farming practices for diverse environmental contexts.