No-till technology has limited potential to store carbon: How can we enhance such potential?

Abstract

No-till is a top soil conservation practice, but if it will be used as a C sequestration strategy, it needs enhancement. Companion practices including N fertilization and irrigation do not often result in net C sequestration or some are unavailable (i.e., biochar) for a large-scale application. Adoption of aggressive or transformative no-till companion practices that genuinely remove CO2 from the atmosphere through photosynthesis and sequester it in the soil as C should be considered. Enhancing both cover crops and crop rotation complexity can be an aggressive biological strategy to boost no-till performance; yet this has not been much discussed. Enhancing cover crops by increasing both the cropland area under no-till cover crops and cover crop biomass production through biomass yield maximization strategies can store more C in the soil than current no-till cover crop management practices. Additionally, inserting multi-year perennial or forages including grasses and legumes into existing no-till row crop rotations could store an additional amount of C. These no-till enhancement practices may not only increase C sequestration in the soil but also boost the overall resilience and ecosystem services from agricultural lands. Their potential can be particularly greater in low C (below C saturation) than high C (at or near C saturation) no-till soils.