Leslie, A.1; Hooks, C.R.R.2
1Agriculture and Food Systems Educator, University of Maryland, Bel Alton, MD, 20611
2Associate Professor, University of Maryland, College Park, MD, 20742


Organic vegetable farmers rely on tillage and cultivation as tools to control weeds, which can increase production costs and negatively impact soil health. Growing organic vegetables under reduced tillage is made even more difficult because of a lack of effective and affordable herbicides labelled for organic use. Organic mulches produced by winter cover crops can effectively suppress weeds in no-till agronomic crops, and can potentially allow vegetable crops to be grown with reduced tillage. Here, we present results of a three-year project testing whether winter cover crops can provide season-long suppression of weeds in a bell pepper (Capsicum annuum) crop. Our experiment tested three treatments using an annual cover crop mixture of rye (Secale cereale) and crimson clover (Trifolium incarnatum) and one treatment using perennial red clover (Trifolium pratense). The rye/crimson clover treatments each received different amounts of tillage: a conventional tillage (CT) treatment was rototilled to incorporate all cover crop residue, a no-till (NT) treatment was flail mowed and pepper transplants were planted directly into the resulting residue, and a strip-till/roller crimp (ST-RC) treatment was rolled and tilled only within the strips where peppers were transplanted. The red clover treatment was also strip tilled, and the remaining clover was allowed to remain as a living mulch (ST-LM) between pepper rows. The ST-LM treatment significantly reduced weed biomass production compared to all other treatments, and significantly reduced the amount of labor required to control weeds. The CT treatment consistently produced the highest yields, however ST-LM out-yielded other reduced tillage treatments. Living mulch and strip tillage show promise as an effective method for suppressing weeds under reduced tillage vegetable production.

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