Skip to main content
ARS Home » Plains Area » Bushland, Texas » Conservation and Production Research Laboratory » Soil and Water Management Research » Research » Publications at this Location » Publication #343647
Research Project: Precipitation and Irrigation Management to Optimize Profits from Crop Production

Location: Soil and Water Management Research

Title: Evaluating deficit irrigation management strategies for grain sorghum using AquaCrop

Author
item ARAYA, ALEMIE - Kansas State University
item KISEKKA, ISAYA - Kansas State University
item HOLMAN, JONATHON - Kansas State University

Submitted to: Irrigation Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/8/2016
Publication Date: 7/26/2016
Citation: Araya, A.B., Kisekka, I., Holman, J. 2016. Evaluating deficit irrigation management strategies for grain sorghum using AquaCrop. Irrigation Science. doi:10.1007/s00271-016-0515-7.

Interpretive Summary: Many wells on the Southern High Plains drilled into the Ogallala Aquifer can no longer meet full crop water requirements due to declines in Ogallala aquifer water levels. However, these sites are capable of contributing to the regional agricultural economy under appropriate management protocols. Therefore, scientists in the ARS led Ogallala Aquifer Program from Kansas State University conducted a study to determine optimum limited irrigation strategies for grain sorghum with varying planting dates. Planting date was found to substantially affect biomass and grain yield with the highest grain yields with late planting in a wet season. Late planting was associated with lower irrigation requirements. Fluctuations in grain sorghum prices had a substantial impact on economic water productivity. Overall planting grain sorghum under optimum conditions combined with deficit irrigation improved water productivity.

Technical Abstract: Many wells in the US Central Plains can no longer meet full crop water requirements due to declines in Ogallala aquifer water levels. A study was conducted in Southwest Kansas to determine optimum limited irrigation strategies for grain sorghum. Objectives were to (1) calibrate and validate the AquaCrop model, (2) apply AquaCrop to assess the effect of varying climate, planting dates, and soil types on yield, and (3) evaluate water productivities and optimal irrigation needs. Experimental data of grain sorghum were used to calibrate and validate AquaCrop. Planting date was found to substantially affect biomass and grain yield, and hence, considerably affect water productivities. The highest grain water productivities were obtained with late planting in a wet season. Late planting was associated with lower irrigation requirements. Depending on local conditions, we recommend planting to occur between June 1st and June 10th. Grain sorghum yield was optimized on sandy soils of southwestern Kansas with irrigation of 100–275 mm for early, 150–275 mm for normal and 100–275 mm for late planting. The optimal irrigation on silt loam soils for the corresponding planting dates were 175–350, 175–250 and 125–250 mm, respectively, with the lowest and highest in the range being for the wet and dry climate season conditions. Fluctuations in grain sorghum prices had a substantial impact on economic water productivity. Overall planting grain sorghum under optimum conditions combined with deficit irrigation improved water productivity.