Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: November 1, 2006
Publication Date: November 15, 2006
Citation: Colaizzi, P.D., Evett, S.R., Howell, T.A. 2006. Subsurface drip irrigation (SDI) research at USDA-ARS in Bushland, TX. Proceedings of the First International Conference on Water in Arid and Semiarid Lands (ICASALS), November 15-17, 2006, Texas Tech University, Lubbock, Texas. 10 p. Interpretive Summary: Producers in the Texas High Plains have recently adopted subsurface drip irrigation (SDI) at unprecedented rates in response to drought, declining water resources from the Ogallala Aquifer, and increasing energy costs to pump groundwater. There is some evidence that SDI offers potentially greater crop yields, water use efficiency, and maintains warmer soil temperatures compared with typical sprinkler packages used on center pivot irrigation systems. This paper reviewed SDI research conducted at the USDA-ARS in Bushland, TX from 2000 to 2006. Crops included grain sorghum, cotton, and soybean. Crop yield, seasonal water use, and water use efficiency (WUE) were compared for SDI and center pivot irrigation. A range of irrigation application rates were used, from dryland to meeting the full crop water requirement. The SDI generally outperformed the center pivot at low irrigation rates, but center pivot was often as good as or better than SDI at higher irrigation rates. Soil temperature was compared between SDI and center pivot, with SDI generally maintaining warmer soil temperature, which is important for cotton production. Crop emergence was compared between SDI and center pivot for soybeans. Crop emergence tended to be less with SDI but this did not affect final soybean yield.
Technical Abstract: Producers in the Texas High Plains have recently adopted subsurface drip irrigation (SDI) at unprecedented rates in response to drought, declining water resources from the Ogallala Aquifer, and increasing energy costs to pump groundwater. However, SDI has much greater capital and maintenance requirements, and crop germination may be difficult without supplemental early-season precipitation. We compared crop yield, seasonal water use, water use efficiency (WUE), emergence, and near-surface soil temperatures among SDI, LEPA, and spray for a range of irrigation capacities for grain sorghum, cotton, and soybean. At low irrigation capacities, SDI resulted in greater crop yield and WUE compared with LEPA or spray irrigation; however, at high irrigation capacities, spray sometimes resulted in the greatest crop yield and WUE. SDI resulted in warmer soil temperatures than spray irrigation for soybean and cotton. Crop emergence was generally numerically less with SDI compared with LEPA or spray for soybean, but inconsistent for cotton. Crop emergence and final yield were also evaluated for alternative SDI bed designs (laterals centered in twin rows vs. laterals in alternate furrows) and lateral installation depths (15-, 22-, and 30-cm) for soybean. The twin row design at the 22-cm lateral depth generally resulted in the greatest emergence; however, there were no significant differences in final yield. These results suggest that presently, SDI may have the greatest economic justification for cotton production at low irrigation capacities.