Submitted to: Soil and Water Conservation Society
Publication Type: Abstract Only
Publication Acceptance Date: 3/14/2012
Publication Date: 7/29/2012
Citation: Baumhardt, R.L., Schwartz, R.C., Howell, T.A. 2012. Using conservation tillage to increase yield and water use efficiency of corn and cotton under deficit irrigation. [abstract]. Soil and Water Conservation Society. Paper No.61319939.
Technical Abstract: Southern High Plains producers supplement the erratic growing season rainfall with irrigation using ground water from the Ogallala Aquifer. Increased pumping costs and declining well capacities in this region require improved precipitation capture and crop water use efficiency to maintain production stability and profitability. Separate blocks of corn (Zea mays L.) and cotton (Gossypium hirsutum L.) were grown in rotation with wheat (Triticum aestivum L.) and intervening fallow to store precipitation in a disk, sweep, and no till Pullman soil (fine, mixed, superactive, thermic Torrertic Paleustoll) at the USDA-ARS Conservation and Production Research Laboratory, Bushland, TX. Summer crops were irrigated by lateral move mid-elevation sprinklers in blocks receiving about 25 or 50 mm every 10-14 days, which correspond to limited, but common, well pumping capacities for the region. Crop water use was estimated from a soil water balance of measured precipitation, irrigation, and soil water content and evaluated in relation to crop growth and yield. Residue retaining no-till reduced evaporation and increased the soil water stored during fallow from 40 mm to 80 mm compared with sweep and disk tillage. Cumulative ET increased with increasing irrigation, but residue retaining sweep and no-till practices did not affect ET compared with disk tillage. Compared with disk tillage, no-till corn and cotton yields increased 80% and 50% under irrigation of about 2.5 mm d**1. At the higher about 5.0 mm d**1 irrigation rate no-till yields increased 25% and 40%. We conclude that residue reduced growing season evaporation, which increased water use efficiency and crop yields.