Controlling weeds in vegetable farming is a major concern. Most growers use conventional tillage practices. Excessive tillage, however, decreases organic matter and affects the soil’s biological, physical, and chemical structure. Cover cropping and reduced tillage techniques may help to mitigate some of these negative effects. In August 2009, a three-year study of cover crops and tillage techniques commenced at the University of Rhode Island Greene H. Gardner Jr. Research farm. A randomized complete block design consisting of twelve 10 X 50m plots were assigned one of the four cover crop and reduced tillage treatments. Each plot consists of six 1.5m beds. The four interior beds were planted with vegetables while the outer two were planted only with cover crops to serve as a buffer between treatments. Four objectives investigated for this study include:  To determine how the treatments affect weed density and abundance.  To measure the changes in soil health over time.  To determine how yield is affected by the treatments.  To determine if one of these specific treatments is a viable alternative for southern New England vegetable growers. We hypothesize that one or more of the treatments will reduce weed populations while improving soil health and yield. Six vegetable crops: carrot, salad mix, melon, cucumber, tomato and cabbage were chosen for evaluation. Tomatoes and cabbage were planted in individual rows while the cucumber, melon, salad mix and carrots were alternated in a single row. Marketable yield totals (kg/ha) for each season were analyzed for statistical difference between treatments. Figure 1. Effect of cover crop treatments on marketable yield (kg/ha) for 2010 and 2011 growing seasons. Different letters show statistical difference (P < 0.05) between treatments. Cover Cropping Strategies for Year-Round Weed Control On Mixed Vegetable Farms In Southern New England Jeff Pieper and Rebecca Brown Department of Plant Science and Entomology University of Rhode Island, Kingston, RI Yield Soil Health Weed Abundance Introduction / Objectives Weed density (presence/absence) was determined using a 1 X 0.5m grid consisting of 50 10X10cm squares in four randomly located sites. Data was collected on four dates. Weed density and species composition was analyzed for statistical differences between treatments. Acknowledgements We would like to acknowledge the following for their hard work and help in making this research possible: Carl Sawyer, Tim Sherman, Mina Vescera, Noah LeClaire Conway, Emily Cotter, and Woods End Laboratories This project was funded by grant number LNE from Northeast SARE Six soil samples were collected from four randomly located sites every 2 weeks. The soil was processed according to Haney-Brinton test methods, and analyzed for CO 2 -C ppm using the Solvita® digital color reader. Treatments Conventional: Fall planted winter rye (Secale cereale L.), is plowed under and disked twice the following spring. Tractor-mounted and walk- behind rototillers will be used to control weeds within the plots. Roller crimper: Fall planted winter rye is terminated using a front mounted roller crimper the following spring. A zone builder implement is used to create a strip-tilled area for planting in the rolled rye. Figure 2. Average number of weeds present per treatment. Significant difference (P < ) was observed when comparing presence of weeds in the perennial rye/white clover treatment to all other treatments. Figure 3. The five most prevalent weed species and their abundance by treatment. Different letters show statistical difference (P < 0.05) between treatments Yield: The current harvest of melons, cucumbers and lettuce is underway. This season, cabbage transplants were used to overcome germination problems with direct seeding. We have also invested in new equipment to enhance our lettuce and carrot yields in all treatments. Weed Abundance: Presence/absence data continues. We are also taking bulk density samples of weeds and cover crops. This will account for the size of weeds and help to determine the effect of cover crop density on weed abundance. Soil Health: We have just received our final Cornell Soil Health report, and are halfway through our second year with Solvita®. Figure 4. Soil respiration throughout the 2011 growing season. Over the course of the year, no significant differences (P < 0.05) were found between treatments. Perennial ryegrass/white clover: Perennial ryegrass (Lolium perenne L.) and Dutch white clover (Trifolium repens L.) serves as a perennial cover crop. Weekly mowing is used to control cover crop and weed growth. Winter rye will replace the vegetables in the fall. A walk-behind tiller incorporates the rye in the spring. Crimson clover: In the spring, the plots will be plowed and disked. After vegetable planting, crimson clover (Trifolium incarnatum L.) is seeded and serves as living mulch. Mowing is used control crimson clover and weeds. Cover and vegetable crop residue will remain throughout fall and winter. Current Research Conclusions Yield: In both years all yields from the roller crimper treatment were significantly lower than the conventional treatment. When compared to the conventional treatment, significant yield differences (P < 0.05) were observed in tomato (2010), melon (‘10 & ’11), and cabbage (’11). Poor germination of carrot and lettuce resulted in no measureable yield for Weed Abundance: The perennial ryegrass/white clover treatment had significantly fewer weeds present (total) than the other treatments. Crabgrass (Digitaria spp.) has proven to be the most abundant and difficult to control. Soil Health: Results from the Solvita® tests showed no significant difference between treatments. The majority of the results were in the CO 2 -C ppm range, suggesting moderate to low organic matter and microbial activity. Cornell Soil Health tests suggested results similar to the Solvita  findings for both 2010 and 2011.