1988 Annual Report for LNE88-005
Cover Crops for New England Vegetable Growers: On-Farm Research, Economic Analysis and Outreach
Summary
As integral components of sustainable agriculture, cover crops can reduce soil erosion and control weeds. In addition, legume cover crops such as hairy vetch will also reduce farmers' inputs of nitrogen fertilizer. Legumes have been shown to be effective cover crops in warm climates, but perceived establishment and hardiness problems have limited their utilization in New England.
These investigators have conducted cover crop experiments with lettuce, no-till sweet corn and no-till as well as conventionally tilled broccoli on New England vegetable farms. Weed dry weights in lettuce plots were the lowest when a buckwheat/rye cover crop was used. A no-till, no-herbicide system of growing broccoli, where rye or oats plus a legume were established then mowed and left in place as mulch prior to planting the seedlings, yielded heads roughly three times as heavy and twice as large as did broccoli following rye alone. Mulches from the grass + legume cover crops released significant nitrogen (N) to the broccoli, as foliar N levels were higher than with rye mulch. Weed suppression was more effective with the grass + legume combination than with rye alone.
When sweet corn was planted without tillage in fields where rye or rye + bigflower vetch were established and then mowed, the residue of rye + vetch resulted in significantly better early-season weed control and greater corn yield than did rye alone. Studies are in progress on optimum seeding and mowing dates for rye + hairy vetch cover crops.
Education and outreach activities include a distribution of about 850 free cover crop seed kits with inoculant and instructions, presentations at several conferences and events, and publication of results in two journals. In addition, two replicated experiments were implemented on seven commercial farms to help demonstrate to farmers the effectiveness of these cover cropping systems.
Future experiments will compare these cover crop systems with conventional methods as well as study various mechanical and chemical management systems for cover crop species.
Objectives
(1) To conduct on-farm research onto cover crops which control erosion, suppress weeds, add nitrogen, and can be adopted by New England vegetable growers.
(2) To collect on-farm economic data for use in enterprise budgets that compare the economics of conventional and alternative cover crops.
(3) To extend information on cover crops to New England vegetable growers.