Growing broccoli to a marketable standard can be difficult in a changing climate with more extreme heat events during the growing season. The use of more heat tolerant Brassica species in combination with living mulch could address both issues. A study in Brookings, SD investigated established clover living mulch and in-row soil management impacts on the performance of four of broccolini (Brassica oleracea) cultivars – ‘Melody,’ ‘BC1611,’ ‘Burgundy,’ and ‘Bonarda.’ Three established clover varieties (‘Domino’ white clover (Trifolium repens), ‘Aberlasting’ white x kura clover (T. repens x ambiguum), and ‘Dynamite’ red clover (Trifolium pratense)) and a bare-ground control were used in combination with four in-row soil management strategies (till, no-till, till fabric, and no-till fabric). These 16 combinations were evaluated for their impact on weed suppression, broccolini crop growth and yield. It was observed that annual weeds such as yellow foxtail (Setaria pumila) and Venice mallow (Hibiscus trionum) were present in bare ground plots and were reduced in all clover plots. Some perennial weeds such as dandelion (Taraxacum spp.) and perennial sow thistle (Sonchus arvensis) were able to compete with clover. Sufficient clover biomass was accumulated for weed suppression. Weed biomass was reduced by 80% in white and red clover plots, and 95% in the white x kura clover plots compared to the control. Broccolini yield was reduced within all three clover no-till treatments. Broccolini grown in other clover soil management combination had similar yields indicating greater resistance to yield decreases commonly observed in living mulch research. Other data collected in this study included clover nodule counts and broccolini crop health metrics – height, canopy width, and SPAD. Results from the first year of research demonstrate that perennial clover living mulch can be used in the Great Plains to suppress weeds between planting rows. However, the use of landscape fabric within the planting row is necessary to prevent a reduction in broccolini yield. Planting broccolini into a living mulch system shows potential for vegetable producers to reduce inputs and labor on their farms while maintaining crop yield.
