Cotton and peanut are major crops in the Southeast, grown on over 10 million acres and worth $16 billion in 2016. Sod-based rotation (2 years of bahiagrass-1 year cotton-1 year peanut) is an economically viable and more sustainable alternative to the traditional cotton-cotton-peanut rotation. Incorporating winter cattle grazing of bahiagrass into the sod-based rotation increases the profitability of the system and results in greater yields and more fertile soil.
Plant-parasitic nematodes are threats to cotton and peanut production with yield suppression estimated at up to 10-15 percent in some Southeastern states, or up to $900 million in losses based on the total value of these crops. Many nematodes decline when bahiagrass is grown, suggesting SBR may be a good system for managing nematodes. Additionally, nematodes can infest deep in the soil profile and crop rotation is one of the few practices that affects nematodes at those depths. This study will assess the level of nematode management provided by SBR, particularly if it is sufficient to reduce or eliminate nematicide application. Reducing nematicide application would save growers money and reduce impacts on the environment.
In addition to pathogens and pests, agricultural soil contains many beneficial nematodes, fungi and bacteria that do not infect plants. These beneficial organisms fill important roles in agricultural systems such as generating natural fertilizers by transforming nutrients into forms that plants can take up. Some beneficial organisms manage pathogen populations by feeding on pathogens or producing compounds that are toxic to pathogens. Because of these services, beneficial organisms can increase crop productivity and reduce reliance on fertilizer and pesticide inputs. SBR has the potential to stimulate these beneficial organisms because crop rotation, manure addition, and cover cropping — all components of SBR — promote populations of beneficial organisms.
Project objectives from proposal:
Based on these needs, the objectives of this project are to:
- Assess the impacts of sod-based and conventional crop rotations on plant-parasitic nematodes and beneficial soil organisms at different depths in the soil profile.
- Assess whether growers can eliminate nematicide application in SBR while maintaining sufficient nematode control.
- Determine the impacts of cattle grazing in SBR on plant-parasitic nematodes and beneficial soil organisms.
- Engage with growers and share research findings through extension efforts.