Tillage used to grow a barley-cotton double crop was reduced by eliminating tillage prior to planting cotton, eliminating cultivations for weed control in cotton, and especially by eliminating tillage following cotton. Small grain residues increased water infiltration into coarse-textured soils (but not on clay soils) and reduced irrigation advance times sometimes increasing the amount of water used to produce cotton. Weed-sensing automatic spot-spray technology reduced the amount of spray volume and herbicide used for cotton weed control. Conservation tillage and cotton-small grain double crop rotations were economically competitive with winter-fallow, conventional cotton production using extensive tillage.
The goal of this project is to provide cotton growers in the Southwestern United States with the necessary economic, agronomic, and physical information required to adopt conservation tillage practices, to utilize cover crops or double crop small grains with cotton, and to utilize weed-sensing sprayer technology. To achieve this goal, five objectives/performance targets have been established:
1. Evaluate the planting of cotton into cover-crop residues or into small grain crop stubble without preseason tillage.
2. Evaluate a weed-sensing sprayer and a post-emergence herbicide weed control program in minimum-till cotton.
3. Evaluate changes in soil properties such as organic matter content, crusting, water infiltration, and associated changes in fertility and irrigation practices.
4. Collect and compare operational, agronomic (i.e., plant growth), and cost data for minimum-till and conventional production systems.
5. Disseminate information on alternative production practices.