Use of cover crops is becoming a common practice among vegetable producers. Cover crops provide multiple benefits such as building of organic matter, erosion and weed suppression, nitrogen fixation, and improvement of soil health. Cereal rye is the most widely planted cover crop in Iowa, however, cover crops such as oats, oilseed radish, and clovers are gaining popularity. The goal of this project was to evaluate and study three fall-planted cover crops and their effect on spring-planted potato. The three cover crops studied were Cereal Rye, Oilseed Radish, and Crimson Clover.
The sandy soils of Muscatine County, Iowa, are prone to erosion and leaching. In the fall, leftover fertilizer applied to the corn and soybean crop is highly susceptible to leaching. Cover crops have been widely acclaimed to mitigate such issues as they prevent erosion and scavenge residual nitrogen. Although these attributes are widely known, adoption of cover crops has been slow. Information on cover crop planting dates, performance, and advantages are available, but few data are available that is applicable to Iowa soils and growing conditions.
The use of tillage is widespread in organic vegetable production, due to its importance for cover crop incorporation, seedbed preparation, and weed control. However, its harmful effects on soil health have spurred interest in systems that reduce the need for tillage. Because nitrogen is often limiting under high residue/reduced tillage conditions, fertilizer management is considered key to crop productivity.
Growing muskmelon in a more sustainable way involves multiple management practices. Cover crops often are incorporated into the soil before planting the cash crop. However, they also can be “rolled” and used as a ground cover throughout the growing season. The cash crop is planted in small, tilled strips within the residue. This “strip-tillage” technique provides a weed-controlling, moisture-retaining mat that does not need to be removed at the season’s end, as plastic mulch does. The reduction in tillage can improve soil structure and health.
Sustainable production of summer squash involves multiple management practices. Some cover crops can be “rolled” when mature to produce a ground-covering mat. The cash crop is then planted in tilled strips made in the residue. This “strip-tillage” technique provides a weed-controlling, moisture-retaining mat that is biodegradable, unlike plastic mulches. The reduction in tillage can improve soil health. Row covers provide a favorable microclimate and act as a physical barrier to pests when placed over young transplants.
There is a growing interest among growers to utilize production techniques that reduce soil erosion, minimize nutrient leaching, suppress weed emergence, and build soil quality and organic matter. Cover crops are now being widely used by both conventional and organic growers to accomplish these tasks and also to maintain high soil fertility.