Development of An Economically and Environmentally Sustainable Cropping System in Semi-Arid Texas: Important Implications for Water Conservation.

Creative and unfamiliar production management techniques may be the most successful in the increasingly narrow economic environment today’s producers must operate under.  Some of these techniques may include the incorporation of cattle into irrigated row crop production, the adoption of tillage practices that do not present a “clean” field, and the manipulation of crop physiology through the imposition of drought stress under precisely timed intervals at controlled levels.  Our team has developed and tested such a cropping system that incorporates cattle grazing during the winter months, and the use of conservation tillage and early season drought stress during the cropping season.  The experiment was initiated in the winter of 2008 when a cover crop of ryegrass (Lolium multiflorum) was established and grazed.  During the cropping season of 2009, the remaining cover (after grazing) was terminated and two tillage treatments (conventional and strip tillage) were combined with three irrigation treatments.  These irrigation treatments included ET replacement at 70% and 100%, and a treatment (we have termed “primed acclimation”) that acclimates the crop to late season drought stress by applying 70% ET replacement during the early developmental stages of the crop and then 100% full irrigation  for the remainder of the season.  For 2009, yield was either equal or greater in the treatment combining conservation tillage and primed acclimation for cotton and corn.  Environmental measurements showed a greater maintenance of soil moisture in conservation tillage, while physiological measurements in the crop show enhanced water-use efficiency and improved stress recovery.  In the winter of 2009, the plots were planted to ryegrass and burr medic (Medicago polymorpha) pasture at the final harvest of all crops.  Evaluation of cattle grazing for the winter of 2009/2010 showed that Bonsmara steers (initial n=72) grazed for 35, 79 and 112 days had average daily gains of 1.38, 1.03 and 1.33 kg/d, respectively.  Crops for 2010 included cotton, corn, peanut, and sesame.