Utilizing Subsurface Drip Irrigation and Conservation Tillage in Cotton Production Systems

Ground water resources for irrigated agriculture are becoming increasing limited in semiarid regions of the world. Subsurface drip irrigation (SDI) and a no-till conservation tillage system were evaluated over 3 years on cotton (Gossypium hirsutum, L.) production and fiber quality in north Texas. Subsurface drip irrigation significantly increased cotton yields over that from furrow irrigation in 2 of 3 yr. When averaged over 3 yr, the cover crop treatments on 1 and 2 m drip line spacing and a 100% ET replacement yielded numerically more than the companion treatments without a cover crop. Across years, the SDI treatments significantly increased loan values by an average of $ 0.045  k g − 1 over furrow-irrigated cotton. Within SDI, deficit irrigation did not appear to affect cotton yield in proportion to the amount of restricted irrigation. In 2003, a 50% reduction in ET replacement under conventional tillage reduced yield only 22%, indicating that a 100% ET replacement may not be necessary to produce economically acceptable yields. Results from this study provide preliminary evidence that cover crops may actually prove beneficial under SDI systems and could play a role in developing best management practices that incorporate conservation tillage practices.