A review on cover crops as a multifunctional ecological regulator in organic crop production systems

Abstract

Organic crop production systems are widely valued for their impacts on environmental and health benefits. However, they often face practical production challenges related to soil fertility, nutrient availability, weed management and overall crop productivity. Cover crops have emerged as an effective, sustainable and adaptable practical solution to address these challenges. This review synthesizes current evidence on cover crops as multifunctional ecological regulators in organic crop production systems with a focus on their role in improving the soil ecological functions by supporting soil physical structure, chemical fertility, and biological activity. To avoid conceptual ambiguity, we distinguish cover crops retained as surface mulch from green manures incorporated into soil, living mulches grown with cash crops, and cover crop-based reduced- or no-tillage systems. It highlights various functional groups of cover crops such as legumes, cereals/grasses, brassicas, and selected broadleaf species, and their mixtures deliver complementary benefits such as nitrogen fixation, nutrient retention, improved soil aggregation, nourishing microbial biodiversity, weed suppression, and accumulation of organic matter. These functions supports the key ecosystem services, ultimately contributing to elevated crop performance across wide range of crops including vegetables, fruits, herbs and ornamentals. However, the effectiveness of cover crop adoption relies on proper management practices, including species selection, termination timing, and alignment of nutrient release to meet crop demand. This review also acknowledges the potential trade-offs, such as nutrient immobilization and resource competition which requires careful consideration in practice. Future research should prioritize understanding the long-term impacts of cover crops, multi-site studies optimizing species mixtures across functional groups, and adaption of cover crops in organic crop production systems to changing climatic conditions. Integrating cover crops with no-till, conservation tillage and precision management offers promising opportunities to enhance overall effectiveness in organic systems. Overall, this review paper highlights the central role of cover crops in strengthening organic production systems by improving soil health, enhancing resilience, and supporting long-term sustainability of organic crop production systems.