Texas High Plains (THP), one of the most important food and fiber producing regions in the Ogallala Aquifer Region, currently faces rapid decline of groundwater levels. Predicted climate extremes and high temporal variability in growing season precipitation may require growers to pump more groundwater from the Ogallala Aquifer to meet higher crop water demand. The Decision Support System for Agrotechnology Transfer (DSSAT) Cropping System Model (CSM) is a widely used crop simulation tool for evaluating impacts of different water and crop management practices, including irrigation on crop yield and water use efficiency. In this study, CROPGRO‐Cotton module of the DSSAT was calibrated and validated using 2000, 2001, 2002, and 2010 irrigated lysimeter field data managed by the USDA‐ARS (United States Department of Agriculture ‐ Agricultural Research Service) Conservation and Production Research Laboratory at Bushland, TX. The lysimeter field consisted of four equal plots designated as NE, SE, NW, and SW. Crop growth characteristics including leaf area index (LAI), above ground biomass (AGB), evapotranspiration (ET), soil moisture, and lint yield of 2000‐NE, 2000‐SE, and 2001‐NE, were used for calibration and 2002‐NE, 2010‐NE, and 2010‐SE were used for validation. The calibrated and validated model was used to simulate the long term (1924–2012) crop yield and seasonal crop ET. During the calibration process, some of the cultivar and ecotype parameters that influence LAI, AGB, and lint yield were adjusted for better statistical results. Measured and simulated LAI, AGB, ET, soil moisture, and lint yield showed good agreement during calibration and validation as indicated by performance statistics such asr²from 0.70 to 0.82, and percent error (PE) = −0.85 to 17.3% for LAI;r²= 0.89 to 0.95, andPE= −7.36 to −13.66% for AGB; andr²= 0.90 to 0.94, and PE = 3.20 to 3.44% for ET during calibration and validation, respectively. The model underestimated ET during peak vegetative growth and development stage except in some circumstances. The calibrated and validated model was able to simulate lint yield and seasonal ET during a long term (1924–2012) historic period for Bushland, TX, under irrigated conditions. The calibrated model could be used to schedule ET based irrigation management practices in the THP and to estimate future ET for other modeling experiments.

Low forage quality of available perennial warm-season grasses during mid-summer through late summer affects the production of stocker cattle in the U.S. Southern Great Plains (SGP). Finger millet (Eleusine coracana Gaertn L.), which is a drought tolerant annual grass, could be a promising forage for the SGP. This field study assessed the adaptability and forage characteristics of 11 finger millet accessions originally sourced (1964–1981) from different parts of the world. Results of this study suggested that finger millet can generate forage yields ranging from 5.0 to 12.3 Mg ha⁻¹ 165 days after planting. Finger millet forage contained 105 to 156 g kg⁻¹ crude protein, 598 to 734 g kg⁻¹ neutral detergent fiber, 268 to 382 g kg⁻¹ acid detergent fiber, 597 to 730 g kg⁻¹ in vitro true digestibility, and 387 to 552 g kg⁻¹ neutral detergent fiber digestibility. Ten of the 11 accessions flowered and produced grains with yields varying from 60 to 1636 kg ha⁻¹. Overall, finger millet has the potential to serve as an alternative crop for the production of forage and possibly grain in the SGP. Further research needs to be focused on developing strategies for agronomic management and evaluating the capacity of finger millet under different grazing and hay production settings in the SGP.

Fields are typically kept fallow after winter wheat (Triticum aestivum L.) grain harvest in the U.S. southern Great Plains (SGP). Introducing summer cover crops to the system could increase soil conservation and farm profitability if grazed. The objective of this research was to evaluate cover crops’ forage yield, residue cover potential, weed suppression, and effect on wheat production. Monocultures and grass–legume mixtures of cover crops were established in mid‐June of 2016 and 2017 near Chickasha and Perkins, OK. At 6 weeks after planting (WAP), three cutting regimes based on stubble height were used: severe (2.5 cm), recommended (legumes: 7.5 cm, grasses and mixtures: 15 cm), and no cutting. Cover crops regrowth was chemically terminated at 14 WAP; winter wheat was no‐till seeded in mid‐October; then harvested in early‐June 2017 and 2018. Cultivar Triple Treat sorghum−sudangrass [Sorghum bicolor (L.) Moench × S. bicolor var. sudanese] and grass−legume mixtures showed the greatest available forage dry matter. Grasses and grass−legume mixtures had greater forage dry matter residue and weed suppression than legumes. Results indicated that exceeding 6.4 ± 1.2 Mg ha⁻¹ of total dry matter (TDM) produced during the summer, a wheat grain yield penalty of −50.1 ± 15.8 kg ha⁻¹ resulted for each increment of 1.0 Mg ha⁻¹ of TDM produced. Also, a wheat protein content penalty of −1.9 ± 0.5 kg ha⁻¹ resulted in each increment of 1.0 Mg ha⁻¹ of TDM produced when exceeding to 5.7 ± 1.0 Mg ha⁻¹ TDM threshold. Findings suggest N uptake by high‐biomass grasses and mixtures might result in deficient water and N availability for wheat production.

Winter wheat (Triticum aestivum L.) is a valuable crop in the southern Great Plains that grows from fall to spring, with fields then typically fallowed through the summer. Adding grazeable cover crops to the fallow period could increase farm profitability. The objective of this study was to determine eight different cover crops’ nutritive value and simulated stocker calf performance. Cover crops were established in late spring 2016 and 2017 in Chickasha and Perkins, OK. At 6 wk after planting, two simulated grazing regimes based on cutting height were used: severe (≤2.5 cm) and recommended (7.5 cm). Legumes had the highest nutritive value in comparison to warm‐season grasses and grass–legume mixtures. Legumes resulted in higher simulated daily steer gain (DSG) and total steer gain per area (TSGA) values than grasses and mixtures at Perkins. At this location, legumes had superior forage nutritive value, compensating for lower yields. At Chickasha, grasses and mixtures had higher TSGA values (246.7 ± 6.9 kg ha^–1) and lower DSG (0.17 ± 0.04 kg steer^–1 d^–1) values than legumes (131.6 ± 25.3 kg ha^–1 and 0.48 ± 0.02 kg steer^–1 d^–1). This finding implied that grasses and mixtures with lower individual DSG required much higher stocking rates than legumes to achieve higher TSGA values. This increment in stocking rates could increase costs, drastically decreasing profits. Consequently, legumes might be a viable option due to their balanced forage yield and nutritive value relationship. However, consideration must be given to supplemental energy to better balance the TDN/protein ratio requirements of the stocker calf.