Performing Department
Biosystems Engineering & Soil Science
Non Technical Summary
Growing organic corn presents many challenges to growers who may be used to growing no-till corn using conventional production systems. Growers need to make decisions on weed control, soil fertility management, variety selection, pest control and marketing. Since 2008 research and demonstrations on organic no-till corn production have been conducted at the East Tennessee Research and Education Center (REC) at Knoxville. Results from our studies have concluded that 1) soil fertility must be corrected before any organic no-till grain should be planted!; 2) a high high biomass legume/grass cover crop mix needs to be established and mechanically killed by rolling prior to no-till planting organic grain crops; 3) using a no-till planter or drill capable of working in high residue situations is critical, without adequate populations weeds will grow out of control; 4) maize yields can approach the state average yield in a near perfect climate.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Goals / Objectives
Recently there has been renewed interest in organic production due to the greater value of organic grains than grain conventionally grown. Smaller farmers are interested in organic grain production but lack information on basic agronomic guidelines including weed control, fertility, populations cover crops species for weed control, and planting dates especially for no-till organic grain production. Our objective it to address these agronomic issues associated with no-till organic grain production. To accomplish this broad objective, this project will research the structure of and risks associated with existing production systems to determine the effectiveness of different no-till and tilled crop management systems and their adoption. Objective 1. Integrate cover crops into CAS to protect soil from erosion; provide weed suppression or control; include crop rotations that could provide forages for livestock; improve soil quality as measured by soil C, decreases risk and vulnerability to drought. Objective 2. Determine the agronomic and economic fertilizer rate for maize planted using different planting configurations in no-till conditions. Objective 3. Characterize the composition and contribution of N and C from legume/grass cover crops and determine the best species for maintaining soil residue cover until after maize crop harvest.
Project Methods
Different cover crop species and planting dates are under evaluation for effectiveness at weed control and suppression as well as durability of the cover crop as a soil residue cover during the next growing season. Our research results indicate that cover crop establishment at the end of the growing season can reduce weed populations by nearly 100% with a continuing effect into the next growing season that extends well past the date of cover crop termination. On the production agronomy side we are evaluating planting dates, plant populations, variety selection, plant populations by fertilizer rate interactions, and mechanical and chemical weed control methods (timing and active ingredient). Soil quality indicators are being evaluated for inclusion into a minimum soil quality dataset; these factors include soil total carbon (C), soil test values, soil depth, microbial biomass C, slope, parent material, and erodibility (from a qualitative standpoint only). During this research we will use participatory and disciplinary research to evaluate farmer perceptions of amendments, their costs, and their effect upon crop yield and economic risk. Baseline soil C samples have been collected and will be collected again in year 5. However, the literature suggests that this time frame is really too short to evaluate soil C source-sink relationships regardless of soil management system. We will evaluate soil CO2 flux along with BR data to try to assess soil carbon dynamics.