Context Matters: Soil Ecosystem Status Varies across Diverse Conservation Agriculture Systems

Conservation agriculture promotes soil health across different management and environmental contexts. While soil ecosystem status (health and functioning) serves as a key indicator of soil health, it remains understudied, with most evidence coming from long-term trials that may not reflect on-farm conditions. Therefore, this study evaluated and compared the long-term soil ecosystem status (health and functioning) of farmer croplands practicing conservation agriculture under two distinct management and environmental contexts. Two sites near Vrede and Reitz (South Africa) were investigated, focusing on conservation agriculture systems, with conventional agriculture and grazed grassland as references systems. Selected ecological indicators (nematode-based indices, organic matter, permanganate-oxidizable carbon, and soil respiration) and physico-chemical properties (particle size distribution, pH, electrical conductivity, and macro- and micronutrients) were assessed to measure soil ecosystem status and the environmental context. At Vrede, pasture and conservation agriculture systems presented elevated organic matter content and microbial activity due to continuous organic cover and minimal physical disturbance. Furthermore, the nematode Maturity Index in these systems was higher, indicating more balanced and healthier soil ecosystems. In contrast, at Reitz, differences between conservation agriculture systems were strongly associated with soil texture differences, influencing organic matter and respiration rates. Additionally, fine-textured soils consistently exhibited greater permanganate-oxidizable carbon values, reflecting the role of soil texture in carbon retention and ecosystem functioning. This study underscores the relevance of both agricultural management and environmental contexts, particularly soil texture, when implementing conservation agriculture systems. It highlights the need for tailored agricultural systems to complement on-farm options and local conditions.