Growth and mineral composition of legume cover crops for sustainable agriculture in southern Mexico

In the tropical region of southern Mexico, legume cover crops are an important resource for the sustainable management of farming systems. The integration of legume cover crops into the farm systems improves soil fertility and weed control. This study compared the growth and mineral characteristics of five legume cover crops on weed suppression and soil nutrient conservation. A randomised block design was used with five legumes (Mucuna pruriens, Vigna unguiculata, Vigna umbellata, Canavalia ensiformis, and Phaseolus vulgaris) as treatments. Coverage, biomass production, and cover crop weed index were assessed at 30, 60, and 90 days after sowing, in addition, relative weed abundance, and mineral composition of cover crops were determined. The cover crops, Vigna unguiculata, Canavalia ensiformis, and Mucuna pruriens, reached total ground covered, had the highest biomass production and suppressed weed growth. There were significant differences in the mineral composition among all cover crops. The nutrients immobilised in the aboveground biomass were Ca > N > K > Fe > Mg > Mn > Cl > Zn > P > Cu. A high richness of minerals was observed in Phaseolus vulgaris, Canavalia ensiformis, Vigna umbellata, and Mucuna pruriens, and a high proportion of nutrient turnover was estimated for Canavalia ensiformis.