Developing Suitable Cover Crop Systems for South Texas: Evaluating Different Late-Summer and Winter Cover Crop Species

View the project final report

Commodities

• Agronomic: cotton, sorghum (milo)

Practices

• Crop Production: cover crops, water management
• Pest Management: integrated pest management

Cover crop systems are widely promoted for their potential benefits on weed suppression, water quality, nutrient cycling, among others. While cover crop systems have witnessed widespread adoption in the northern parts of the country, adoption in places such as south Texas has been very limited. Some of the major limitations include a lack of knowledge to facilitate cover crop selection, insufficient biomass production of covers prior to crop planting in spring and perceived soil moisture loss caused by cover crop growth. Addressing these limitations is pivotal to promote cover crop adoption in the south Texas region.

This project will evaluate both late-summer planted warm-season cover crops as well as fall-planted cool-season cover crops for utilization in early spring-planted cash crops such as grain sorghum and late-planted crops such as cotton, respectively. A total of four warm-season cover treatments (sorghum-sudangrass hyrbrid, sunn-hemp, cowpea and buckwheat) will be established at three planting timings (mid-August, early September, and late September). The winter cover treatments include triticale, oat, shield mustard and winter pea, with three termination timings (mid-March, early April, and late April). These cover crop species and treatments were selected based on our recent preliminary findings. Observations will include soil moisture dynamics, cover crop biomass production, weed suppression during the cover crop growth period, as well as the main growing season, and crop yield. An economic analysis will also be conducted.

The primary outcome of this project is to facilitate informed decision making by growers of south Texas and comparable geographies on cover crop selection and adoption.

1. Evaluate the influence of planting timing on warm-season cover crop growth, summer annual weed suppression and soil moisture demand;

2. Evaluate the impact of the late-summer cover crops on weed suppression, soil moisture dynamics and yield in grain sorghum;

3. Evaluate the influence of termination timing on cool-season cover crop biomass production, winter annual weed suppression and soil moisture demand;

4. Evaluate the impact of the fall cover crops on weed suppression, soil moisture dynamics and yield in cotton.