Andy M. Cranmer, Jim Bordovsky, J. T. Mustian, and D. M. Nesmith. Texas Agricultural Experiment Station, 823 West US Hwy 70, Plainview, TX 79072
Due to the increasing demand and
limited supply of groundwater from the Ogallala aquifer, water use efficiency
and agricultural water savings policies are in the forefront in the Texas High Plains.
The objective of this field experiment was to determine yield and seasonal irrigation
water use efficiency of cotton and cotton/sorghum rotations while evaluating
“water saving” strategies with annual irrigation depths limited to less than 5
inches /year. Field data from a cotton-sorghum
cropping system experiment conducted from 2005 to 2007 at the Texas
Agricultural Experiment Station at Halfway were used. Cropping sequence treatments included CCC –
continuous cotton, CCS – cotton followed by cotton and sorghum, CSC – cotton
followed by sorghum and cotton, and SCC – sorghum followed by two years of
cotton. Three irrigation strategies were
also evaluated; 1) Preplant irrigation only – no in-season irrigation, 2) a
total of five inches of annual irrigation if soil water content at planting was
greater than 50% of field capacity, and 3) a total of five inches of annual irrigation
regardless of initial soil water content.
Strategies will be evaluated based on combinations of crop yields,
commodity prices, and potential value of water saved. Preliminary results show relatively high crop
yields with very limited irrigation over the three year period and that cotton
rotated with grain sorghum has potential for increased cotton yields.