The Trade-Offs of Integrating Newly Established Clover Cover Crops as a Living Mulch in Broccoli Production in the Northern Great Plains

Managing weeds and improving soil health are priorities for South Dakota vegetable farmers. Clover (Trifolium spp.), used as a living mulch within and along cash crop rows, may aid in weed suppression and prevent soil erosion. However, prior research has shown living mulch often leads to yield decreases in cash crops. Research conducted in eastern South Dakota investigated the effects of four clover and four in-row soil management treatments on small-scale broccoli production. Whole plots of red (Trifolium pratense), white (Trifolium repens), and white × kura (Trifolium repens × ambiguum) clovers were direct-seeded in early spring; each clover plot and a bare ground control included four in-row management treatments: no-till + fabric, tilled + fabric, no-till, and tilled. Clover and weed growth were measured throughout the season. During the establishment year, 12.8 cm of precipitation was received, which effectively established the clover living mulch plots. However, in 2023, 5.6 cm of precipitation was received, which negatively affected the clover living mulch plots and created favorable conditions for weeds to outcompete the clover and broccoli. The results highlight the potential challenges and opportunities for managing clover cover crops as a living mulch during the first year of establishment in organic broccoli production.