Short staple cotton under micro and level-basin irrigation methods

Summary Advanced irrigation methods and water management practices are needed for high yields with minimum water applications: A three-year study using recently introduced surface-micro and level-basin irrigation methods was conducted in central Arizona on a nonuniform sandy loam soil to determine optimum water placement and irrigation frequency. Several newer, short staple cotton (Gossypium hirsutum L.) cultivars and different row spacings were also evaluated. Precision micro and level-basin irrigation systems achieved maximum lint yields of more than 2,000 kg/ha and lint water use efficiencies in excess of 0.21 kg/m³. A single micro line per every two rows irrigated daily averaged about 25% more lint cotton than every furrow, level-basin treatment irrigated every two weeks. With a micro irrigation line per every three rows, yields were reduced by an average of 15% and as much as 33% compared with a micro line per every two rows. The cotton production on the narrow row (0.75 m) spacing with a 33% higher plant population outyielded the conventional row (1.0 m) spacing by about 15% in the third year. In addition, some of the newer cotton cultivars had a lower water requirement than the ones prevalent 10 years ago. In the future, cotton growers should be able to irrigate with less water by using improved irrigation systems and water management practices.Contribution of the U.S. Department of Agriculture, Agricultural Research Service, Pacific West Area