Technical and Economical Evaluation of Drip and Furrow Irrigation Methods in Cotton under Deficit Irrigation

With population growing throughout the world, it is necessary to optimize water use, especially in agricultural lands. In order to conduct technical and economical evaluation of drip and furrow irrigation methods under deficit irrigation of cotton, a field experiment was carried out during 2010 growing season at experimental farm of Orzoueyeh Agricultural and Natural Resources Research Center in Kerman province. The treatments were laid out in split plot a randomized complete block design (RCBD) with three replications. The treatments comprised of three levels of irrigation including 100% (control), 80%, and 60 percent of crop water requirement and were allocated to the main plot and two irrigation systems, consisting of furrow (S1) and surface drip irrigation (S2), were laid in the sub plot. The results showed that in comparison with furrow irrigation, drip irrigation increased yield, water use efficiency (WUE), number of bolls per plant, and bolls weight by 8%, 44%, 15% and 33%, respectively. Also, compared with 100 percent of crop water requirement, the 80% treatment reduced water usage by 1900 m3 ha-1, while yield, number of bolls per plant, and bolls weight decreased by 1.6%, 9% and 3.6%, respectively, but WUE increased by 18%. Economic efficiency showed that 80 percent of water requirement in the drip irrigation system was the best treatment. Considering the results obtained in this study and in the light of water saving and higher WUE, as the main objectives in deficit irrigation, for cotton cultivation in Orzoueyeh, application of 80% crop water requirement in the drip irrigation system is preferred.