Cover Crops and Strip Tillage to Promote Soil Quality, Environmental Sustainability, Food Safety, and Profitability in Cucurbit Cropping Systems

View the project final report

• 2015 annual report

Commodities

• Fruits: melons
• Vegetables: cucurbits

Practices

• Crop Production: cover crops, strip tillage

Cucurbit growers in the North Central Region face several critical challenges including increases in extreme rainfall events, increased soil erosion, decreased soil quality, and increased risks of fruit contamination with soilborne plant and human pathogens. For example, recent outbreaks associated with foodborne illness threatened livelihood of melon growers, with Listeria monocytogenes and Salmonella killing consumers throughout the United States. Soil-borne fruit pathogens also significantly affect cucurbit production by reducing yields and grower profits. Adoption of reduced tillage practices, coupled with cover crop residues may help buffer cucurbits from rainfall extremes, improve soil quality and health, and also reduce growth and dispersal of both human and plantpathogens. This collaborative study (Iowa State and Michigan State) will determine whether cover crops combined with strip tillage can be utilized to 1) moderate soil moisture extremes; 2) reduce soil erosion, runoff and leaching; 3) reduce or eliminate Listeria spp. from contaminated cantaloupe fields and Phytophthora capsisi from winter squash fields; and 4) improve crop profitability. We hypothesize that cover crops mulches left on the soilsurface under strip tillage (ST) will promote water infiltration, reduce soil splash and leaching, conserve soil moisture, and form a barrier between the fruit and the soil thereby reducing pathogen spread and survival. In Iowa, field trials will evaluate effects of cover crop (cereal rye, cereal rye + hairy-vetch, and no cover-crop) and tillage (strip till vs. conventional till) on food safety aspect of melon production. In Michigan, field trials will evaluate similar cover crop and tillage treatments and their effects on winter squash production. In both locations, the effects of tillage and cover crops on soil moisture retention, soil splash, disease incidence, yield and fruit qualitywill be evaluated. In Iowa, fields will be inoculated with Listeria innocua (harmless surrogate bacteria for Listeria monocytogenes) prior to planting, and at harvest, samples of soil, cover crop, and fruit will be evaluated for the presence and amount of Listeria innocua. In Michigan, this project will build on a previous SARE project and evaluate long-term cumulative impacts of strip-tillage and cover cropping practices in winter squash production. Working with grower collaborators and an advisory panel, project results will be disseminated through extension/journal articles, local/national conferences and field days. Expected outcomes include increased adoption of strip tillage and cover cropping practices, reduced risks of food-borne illness, enhanced fruit quality, reduced soil erosion and agrichemical runoff and improved grower profitability.

This study will determine whether cover crops combined with strip tillage can be utilized in melon and winter squash production systems to 1) moderate soil temperature and moisture extremes; 2) improve indicators of soil quality; 3) reduce or eliminate contamination due to Listeria spp. from contaminated melon fields; 4) enhance fruit quality, and 5) improve crop profitability. This study will also test the overwinter survival of Listeria innocua and
possible effects of cover crops, if any, on their survival.

This project specifically focuses on production, environment, and economic sustainability in fruit and vegetable cropping systems. Short term outcomes of this project include increased grower knowledge and understanding of the use of cover crops and conservation tillage systems to buffer crops from weather extremes, improve crop yield, and build soil quality. We also expect to show (and measure among farmers) that using cover crops and strip-tillage can reduce soil-loss and nutrient leaching, decrease herbicide application, and improve the quality of melons and winter squash by effectively suppressing the spread and infestation of soil borne-diseases.

Identification and resolution of issues associated with adoption of cover crops and strip tillage also remains an important short-term outcome. In this context, one important area that this project will address is the economic analysis of the proposed cover crop and strip tillage system. Grower adoption of any new practice or technique is directly linked to economic feasibility and viability. Changes in grower behavior in terms of increased adoption of
cover crops and conservation tillage and/or a reduction in the use of herbicides will be some of many medium-term outcomes. We will also monitor farmer emphasis on the importance of soil quality and preventative farm management strategies for sustaining their production systems term outcomes. We will also monitor farmer emphasis on the importance of soil quality and preventative farm management strategies for sustaining their production systems.

In the wake of added emphasis and focus on food safety and quality, this project will highlight strategies which growers could adopt to produce and supply safe and high quality fruit and vegetables. This project will document strengthened collaboration between researchers, extension personnel, growers and grower organizations, local and state agencies and facilitate cohesive and concerted research and education initiatives in
the area of sustainable fruit and vegetable production. We anticipate that outcomes of this project will improve overall resilience and enhance produce quality in cucurbit cropping systems.