Cabbage (Brassica oleraceae var. capitata) is a cool-season cash crop impacted by changing climates and hot summers. Fall-planted cabbage is a common practice hindered by warm-season weed competition during transplanting. This 2023 and 2024 study at the SDSU Southeast Research Farm, Beresford, SD, USA, investigated the impact of established clover living mulch on growth and yield of three fall cabbage varieties with different maturity periods. The varieties selected were Farao (65 DTM), Famosa (81 DTM), and Deadon (105 DTM). One year prior to cabbage planting, three clover cultivars were established: ‘Domino’ white clover (Trifolium repens), ‘Aberlasting’ white x kura clover (T. repens x ambiguum), and ‘Dynamite’ red clover (Trifolium pratense) which were compared to bare-ground control plots. Within each clover whole plot there were four in-row soil management subplots (till, till landscape fabric, no-till, no-till landscape fabric). Combinations of clover, soil management, and cabbage variety were compared for cabbage health, weed suppression, and marketable yield. Harvested cabbage heads were graded in accordance with the USDA Marketable Standard for cabbage cash crop production. Weed biomass decreased as the season progressed and mid-season drought conditions decreased clover growth. The in-row soil treatments demonstrated significant differences for clover and weed biomass accumulation (p < 0.0001). Regardless of variety, cabbage yield and transplant survival decreased within all no-till treatments; this was often due to very small and soft heads. ‘Fararo’ and ‘Famosa’ varieties matured faster than ‘Deadon’, resulting in the cash crop outcompeting weed and clover competition. Clover treatments had the highest impact on the yield of US Number 1 marketable heads (p = 0.02). Cabbage yield within the US Commercial and Unmarketable categories were not impacted by the clover treatments (p = 0.4 and p = 0.06, respectively). The impact of soil management treatments varied depending on the clover variety and cabbage variety combinations. The findings of this study suggest that clover living mulch systems reduce weed competition, minimizing farmers’ workload throughout the season. Within the planting beds, utilization of landscape fabric within no-till treatments is recommended to guard against yield loss. Use of tillage produced marketable crops for all cabbage varieties, yet yield depended on the clover and cabbage variety combination. Organic farmers who grow cabbage within a living mulch system could utilize the living mulch as a benefit for weed suppression in pathways but need supplementary strategies to optimize yield production within the crop row.
