Improving fall vegetable crops and soils with summer cover crops

Project Overview

LS10-230
Project Type: Research and Education
Funds awarded in 2010: $245,000.00
Projected End Date: 12/31/2014
Region: Southern
State: Louisiana
Principal Investigator:
Dr. Carl Motsenbocker
Louisiana State University AgCenter

Annual Reports

Commodities

  • Vegetables: broccoli, cabbages

Practices

  • Crop Production: cover crops, multiple cropping, tissue analysis
  • Education and Training: extension, farmer to farmer, networking, on-farm/ranch research
  • Farm Business Management: budgets/cost and returns
  • Natural Resources/Environment: carbon sequestration
  • Production Systems: organic agriculture
  • Soil Management: organic matter

    Abstract:

    This three-year research project was to investigate and assess the use of summer cover crops (SCC) in fall/winter vegetable production systems in Louisiana, Mississippi and Alabama on research stations and at collaborating farms.  The use of summer cover crops represents a strategy to improve or stabilize soil quality and health and also enhance vegetable crop nutrient management. The specific goals of this project were to: 1) investigate relative productivity and soil building properties of summer cover crops; 2)  determine the influence of summer cover crops on subsequent vegetable crop productivity; 3) increase the knowledge base of organic and sustainable producers, extension and educational professionals; and 4) increase the profitability of regional vegetable farmers.  At LSU AgCenter’s research station in Baton Rouge and Mississippi State’s research station in Crystal Springs, cover crops were established in the summer and then harvested followed by soil incorporation.  A late fall/winter vegetable crop was then established (2010 – cabbage; 2011 – broccoli, 2012 – lettuce) with varying rates of composted chicken litter organic fertilizer.  The research in 2010 demonstrated the differences in biomass due to cover crops harvest timing (60 vs. 90 days) with the biomass from the 90 day harvest excessive and creating an in issue with managing harvesting and incorporating of both sesame and Crotalaria.  Sesame and the 90 day harvest timing reduced the yield of cabbage while increasing fertilizer positively impacted yields. In 2011 and 2012, cover crops (Sorghum-Sudangrass, sesame, Crotalaria, sesame + Crotolaria) were evaluated. Sorghum-Sudan grass cover crops significantly lowered the yield of broccoli unless combined with increased rates of composted broiler litter fertilizer.  All other cover crops had no significant influence on yield, even across broiler litter applications. As the broiler litter fertilizer rate increased, broccoli yield increased within and across cover crops.   In 2010, a summer cover crops cultivar screening evaluation was conducted at both locations with 31 entries in unreplicated field trials.  The findings included the suitability of Japanese millets and Sorghum-Sudangrass for short-term cover, and the promise of several small seeded legumes.  A demonstration plot was conducted in Lorman, AL in 2011 and 2012 with Sorghum-Sudan grass for fall vegetable crops and an on-farm cover crops study in Meadeville, MS in 2010 and 2011 in a fall vegetable rotation.  The project showed 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 addressed in order to provide environmental and economic benefits of using SCC without causing planting delays for the winter vegetable crop.

    Project objectives:

    Determine the relative productivity and soil building properties and soil health of summer cover crops in Gulf Coast organic farming systems. 

    Determine the influence of summer cover crops on subsequent vegetable crop productivity. 

    Enhance the knowledge base of area outreach and educational professionals serving the needs of organic and similarly minded farmer-marketers in the Gulf States. 

    Develop production budgets for the various summer cover crop treatments and the fall organic vegetable crops. 

     

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.