Legume Cover Crops Enhance Nutrient Cycling and Biomass Production in a Lettuce–Lettuce–Oat Cropping Sequence in a Pot Experiment
Year: 2026
Type: article
Abstract: This study evaluated the performance of seven cover crop species, five legumes, one grass, and one brassica, and their residual effects on a lettuce–lettuce–oat rotation. A completely randomized design with eight treatments and three replicates was established in 10 L pots to assess biomass production, nutrient accumulation, and impacts on subsequent crops and soil properties. Legumes produced significantly higher biomass and nitrogen (N) accumulation than non-legumes, with more than 96% of their N derived from the atmosphere, indicating strong N limitation in the system. Differences among legume species were also observed. Although legumes showed lower concentrations of phosphorus (P) and other nutrients in plant tissues, this was attributed to a dilution effect associated with greater biomass production rather than restricted nutrient uptake. Cover crops had marked effects on subsequent cash crops. Crops grown after legumes showed significantly higher biomass, N status, and photosynthetic performance than those following non-legumes or the control. These effects were strongest in the first crop but persisted throughout the rotation. In contrast, non-legumes did not differ from the control. N recovery proved to be a sensitive indicator of these differences, confirming the key role of legumes in supplying N through residue mineralisation. Legumes also influenced soil properties by increasing nitrate availability and soil organic carbon (C), mainly due to greater biomass inputs, but promoted slight soil acidification, likely associated with enhanced nitrification. Overall, the results highlight the importance of species selection, with legumes playing a central role in improving soil fertility and crop productivity in sustainable cropping systems.
Source: Horticulturae
Language: English
Subfield: Agronomy and Crop Science
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,654
OpenAlex ID: W7212159758