By Chen Na
Researchers have discovered that using cover crops as "living mulch" between rows of maize can significantly improve soil health and nutrient cycling, offering a sustainable approach to agricultural management.
The research, conducted in Changtu County in northeastern China, investigated the effects of different types of cover crops—legumes, grasses, and a mixture of both—on soil properties and microbial communities.
The paper is published in the journal Agriculture, Ecosystems & Environment.
Cover crops, planted during or after the main crop's growth, help prevent soil erosion, improve fertility, and increase the input of plant-derived nutrients. Soil degradation, driven by unsustainable farming practices, poses serious threats to food security and regional agricultural development.
Cover crops offer an integrated "use-and-maintain" solution to restore degraded farmland. While earlier research has focused on the effects of decaying cover crop residues, this study examined the impact of living cover crops growing alongside the main crop.
The research team from the Institute of Applied Ecology of the Chinese Academy of Sciences in Shenyang conducted a field experiment where maize was intercropped with different cover crop treatments.
The researchers found that legume cover crops increased dissolved organic carbon and available nitrogen in the soil, altering the microbial community structure and promoting carbon cycling. This alleviated microbial carbon limitation, thereby granting microbes easier access to the carbon they needed to thrive.
Grass cover crops, on the other hand, helped maintain soil carbon and total nitrogen levels while boosting overall microbial biomass, particularly among bacterial groups.
The most promising results came from the mixed cover crop treatment, which combined the benefits of both legumes and grasses. This approach improved both carbon and nitrogen levels while maintaining overall soil nutrient balance. Additionally, the mixed treatment also significantly enhanced microbial functions, as evidenced by the temporal dynamic shifts in microbial functional groups revealed in the study.
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