Improving fall vegetable crops and soils with summer cover crops

Improving fall vegetable crops and soils with summer cover crops

Summary

The use of summer cover crops (SCC) in fall/winter vegetable production systems represents a strategy to improve or stabilize soil quality and health, and vegetable crop nutrient management. We have shown that several SCC crops have promise for use in vegetable production. Management of SCC in terms of stand establishment, length of growing season, harvest and soil incorporation, and management flexibility are issues that the project have addressed in order to provide environmental and economic benefits of using SCC without causing planting delays for the winter vegetable crop. Each season, more growers express an interest in trying SCC on their farms.

Objectives/Performance Targets

Accomplishments/Milestones

The summer cover crop study at Baton Rouge was continued, a duplicate of the study established in Crystal Springs, MS. The study was replanted to summer cover crops using the identical planting plan to that of 2011. Cover crops yield and soil data were taken in September and a fall broccoli crop was established in subplots using the same plot plan as the previous year with various composted fertilizer treatments. The broccoli was harvested in winter and soil and leaf tissue data was collected to compliment the summer cover crop yield data taken. All sampling was intended to document the effects of the cover crops and composted chicken litter applications on soils and the subsequent broccoli crop yield. There were significant influences of broiler litter compost on broccoli yield although the summer cover crops had less influence than the compost on broccoli yield. Additional data analysis, including changes in soil characteristics over the life of the study were on going as of Dec. 2012.

Work that is left to be accomplished: The cover crops field trial at Baton Rouge will be conducted for a third year with the same research protocols as 2011 and 2012. Production budgets for the various summer cover crop treatments and the fall organic vegetable crops need to be developed.

The Mississippi team maintained two studies in 2012. They continued the main summer cover crop study at Crystal Springs and established a composted broiler litter rate study at Lorman. In June 2012, the main study, a duplicate of the study established at Baton Rouge, Louisiana, was replanted to cover crops using the identical planting plan to that of 2011. After taking yield and soil data in late August, a fall broccoli crop was established in subplots using the same plan as in 2012. The broccoli was harvested in December 2012. Soil and leaf tissue data was collected to compliment the summer cover crop yield data taken. All sampling was intended to document the effects of the cover crops and litter applications on soils and the subsequent broccoli crop. The soil, tissue, and yield data were analyzed and tabulated as part of a Masters’ student thesis in the fall of 2012. There were significant influences of broiler litter compost on broccoli yield, as well as soil and broccoli leaf tissue nutrient concentrations. Cover crops had less influence than the compost on broccoli yield, although there was a strong negative influence of sorghum-sudan grass on subsequent broccoli yield. Additional data analysis, including changes in soil characteristics over the life of the study were on going as of Dec. 2012.
The cover crops field trial at Crystal Springs will be conducted for a third year with the same research protocols as 2011 and 2012. Production budgets for the various summer cover crop treatments and the fall organic vegetable crops need to be developed.

The Lorman location tested one cover crop and four rates of composted broiler litter on subsequent broccoli yield. Data on broccoli yield was collected near the end of 2012 and was being analyzed at the end of this reporting period.

Impacts and Contributions/Outcomes

Two field days were held that included the plots at Baton Rouge. The total vegetable grower attendance was estimated to be over 100. Numerous phone calls and internet questions about cover crops and vegetables were received during 2012. Data from the Baton Rouge work was presented at the American Society for Horticultural Science (ASHS) annual meeting in summer 2012 as well as the Southern Sustainable Agriculture Working Group.
Two field days were held that included the plots at Crystal Springs, and one at Lorman, MS. Total attendance and views are estimated to be over 500 people across these field days. Dr. Evans and Dr. Panicker received numerous phone and internet questions about cover crops and vegetables during 2012. Data from the Crystal Springs work was presented in the graduate student competition at the American Society for Horticultural Science (ASHS) in summer 2012. Other data was presented to the Soil Science Society of America, the National Small Farmers Conference, the Southern Sustainable Agriculture Working Group, and the Southern Region ASHS annual meeting in 2012, and the Missouri Organic Growers Association. The M.S. student on the project proposed a follow on study to the SSARE Graduate Student Research program.
A graduate student completed their field work and began writing a thesis before the end of December 2012. They are expected to graduate in May 2013.
In general, the cover crops field research trails in Mississippi and Louisiana provide information in order for vegetable growers to make informed decisions on the use of cover crops in winter vegetable production.

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