Conservation agriculture: enhancing soil fauna richness and abundance in low-input systems: Examples from Kenya
Soil living organisms, including the large-sized (macrofauna) and small-/medium-sized (mesofauna) organisms, among others, play important roles in improving soil conditions and driving ecosystem stability, nutrient availability, and improvement of soil fertility. These organisms can break down (decompose) soil organic matter, make underground tunnels that improve soil water-holding capacity, and increase soil moisture retention. In addition, some soil living organisms, especially the predacious groups, can reduce incidences of pest damage to crops through preying on certain field pests (insects), thus increasing crop yield.
In many instances, conventional tillage systems (the normal practice involving repeated cultivation with limited inputs) have been associated with several disadvantages involving nutrient losses, reduced moisture retention, soil erosion, and a reduction in population abundance of soil biodiversity (soil dwellers) compared with conservation tillage. These disadvantages have been established to be true over the years. Practicing conservation agriculture (a system with minimal or zero tillage, residue retention among other inputs added, and crop rotation) has been shown to solve these problems! Reduced tillage has the potential to increase soil health, improve the population of organisms living in the soil, and increase organic matter accumulation, leading to soil structural stability. In addition, despite the lower input demands than with conventional tillage, conservation agriculture can increase soil health, fertility, and productivity in several ways.