Increasing Farm Sustainability through the Use of Cover Crops for Weed Suppression in Non-Transgenic Conventional Cotton

View the project final report

• 2004 annual report
• 2005 annual report

Commodities

• Agronomic: cotton, oats

Practices

• Crop Production: conservation tillage
• Education and Training: demonstration, display, extension, farmer to farmer, on-farm/ranch research
• Natural Resources/Environment: biodiversity, soil stabilization
• Pest Management: allelopathy, integrated pest management, mulches - killed
• Production Systems: general crop production
• Soil Management: organic matter, soil quality/health

Transgenic cotton including the Round-Up (RR) varieties first appeared in 1997 and now occupies approximately 90% of the cotton planted in Georgia and the other southern states. Within Georgia alone reduced tillage systems are used on approximately 600,000 acres. There is concern that continued reliance on RR cotton will create weed species with resistance to glyphosate (actual Round-Up chemical). Resistant weed species may require potentially more toxic herbicides to be used or growers will have to revert back to using plowing methods as a means of weed control. Either method of weed control will be detrimental in making these southern farms sustainable systems. Therefore the farmer needs an alternative method of weed control other than transgenic cotton varieties which relies or encourages over use of glyphosate.

We will demonstrate that heavy cover crop residue is effective in suppressing weeds by measuring weed biomass, herbicide use, cotton lint yield and quality in three different farming systems. All of these farms are using reduced tillage as their tillage method; the use of cover crops however has been different. The three different farm systems to be used in this study are: 1) a system that has been using only winter weeds as cover will plant black oats as a cover crop and will plant a conventional cotton (variety DP493); 2) a system that has been using rye cover crops for over six (6) years will plant black oats and DP493 and; 3) a system that has used a rye cover crop will plant black oats and a RR cotton (DP555BR). The use of a RR cotton will provide a comparison between similar farming practices for conventional and RR varieties of cotton. All plots will be set-up so that three sub-plots of one-tenth acres (4-36 inch rows by 363 feet) will be monitored.