Cover Cropping Strategies for Year-round Weed Control on Mixed Vegetable Farms in Southern New England, Poster Board #329

Fall planted winter rye is a common cover crop for Southern New England vegetable farmers.  In spring the winter rye is plowed under and conventional tillage is used to control weeds.  These practices can lead to increased labor and fuel costs and can also degrade soil quality. In an ongoing three-year experiment, we are investigating how a conventional rye cover crop affects vegetable yield, nutrient cycling, and weed density in mixed vegetable systems.  We are comparing three alternate cover crop and tillage treatments to the conventional method. One treatment uses beds of fall planted winter rye that are rolled and crimped in the spring; the rolled and crimped rye formed a mulch layer intended to suppress weeds.  A second treatment uses perennial rye and dwarf white clover as living mulch between raised beds. The last treatment, crimson clover, is tilled only in the spring and the clover is seeded after vegetables are established. The four treatments were assigned to 10 x 50 meter plots, and each treatment is replicated three times.  Tomatoes, cucumbers/melons, salad/carrots, and cabbage are planted in each treatment. Marketable and nonmarketable yield is recorded for each crop Soil quality is evaluated biweekly through the growing season using Solvita soil respiration kit. Each spring, samples are also collected for Cornell’s soil health assessment test.  Weed densities were recorded four times during the season. A 0.5 meter grid transect was used to tally presence and absence of 7 agriculture weeds in each plot. No herbicides were used in our study.  We hypothesized these three treatments could maintain vegetable yield while increasing soil quality and decreasing weed density. The roller crimper winter rye treatment was ineffective at preventing weeds and failed to produce a marketable yield for any crop. Other treatment effects on yield are crop specific. While the crimson clover/no till treatment showed increased tomato yield, cabbage yield was higher in the conventional treatment.  Melon and cucumber yields showed no difference between the crimson clover, conventional, and perennial rye and dwarf white clover treatments.  Weed densities were lower in the conventional treatments.  Weeds had a large effect on cabbage, leading to small heads and low yields. Repeated measures analysis of the Solvita soil test shows no difference between the treatments.