Location: Water Management and Conservation Research
2020 Annual Report
Accomplishments
1. Effects of sprinkler irrigation rate and timing on Arizona cotton production. Arizona agriculture faces several problems related to water: on-going regional drought, depletion of water in reservoirs, competition from cities, and climate uncertainty. Improving efficiencies of agricultural water use is imperative for the sustainability of Arizona row-cropping. ARS researchers in Maricopa, Arizona, conducted a three-year field study on cotton irrigation practices, which revealed impacts of early-season and late-season irrigation levels on cotton yield, water use, and fiber quality. With improved scientific tools, irrigation could be reduced by 10% while maintaining acceptable cotton yield and fiber quality. The study provides valuable guidance for producers and water management planners in the region, specifically on irrigation practices for cotton using overhead sprinkler irrigation systems.
2. High guayule rubber yield using subsurface drip irrigation (SDI). Guayule, a perennial desert shrub, produces high-quality natural rubber that is suitable for use in commercial-grade tires and major tire companies in the United States have revitalized interest in developing large domestic U.S. supplies of natural rubber to alleviate dependency on imported and synthetic rubbers. Guayule is acclimated to hot, arid environments, but to attain high rubber yields in the desert requires significant amounts of water when using traditional flood irrigation methods. ARS researchers in Maricopa, Arizona, conducted irrigation studies for two and a-half years to compare rubber yield and water use using both flood irrigation and the more efficient, subsurface drip irrigation (SDI) method. Key results were that rubber yields were nearly doubled using SDI over flood irrigation and that water savings can be greatly increased with SDI. This study provides irrigation technology that will help future guayule growers to attain high rubber yields while minimizing water use.
3. Nitrogen (N) management practices for subsurface drip irrigated (SDI) cotton. Declining water availability in the American Southwest continues to generate interest in efficient subsurface drip irrigation (SDI) for cotton production. Fertigating urea ammonium nitrate at low rates with high frequency is an important advantage of SDI, but nitrogen (N) fertilizer management guidelines, specific to SDI cotton are lacking. ARS researchers in Maricopa, Arizona, conducted a 3-yr study to test a pre-plant soil profile NO3 algorithm and a canopy reflectance approach to manage in-season N fertilizer for SDI cotton. Nitrogen recovery efficiency of added N was high with 24 fertigations during the 6 weeks between first square and mid bloom, ranging from 58 to 93%. The key result of this study is that reflectance-based N management saved 17 to 112 kg N ha-1 without reducing lint yields, compared to the soil test-based N treatment This technology can save cotton growers money on fertilizer in all regions that utilize SDI, which will partially offset the expense of installing a new SDI system.
4. Satellite-based remote sensing of evapotranspiration. Efficient irrigation management relies on timely information about crop water requirements and a practical and widely used method to estimate crop water requirements, “FAO56”, estimates water use of a crop by multiplying a crop coefficient by reference water use value determined from weather station data. However, coefficients change over the season and are difficult to estimate every day. ARS researchers in Maricopa, Arizona, determined the actual daily crop coefficient and water use of wheat crops using remote sensing information from satellites. The approach accurately estimates the daily measured water use, particularly during periods when the need for irrigation was the greatest. ARS is collaborating with private growers atnthe University of Arizona, and a private technology firm, to implement these results into accessible, low-cost tools for water management. These results will lead to future development of this remote sensing technology for providing reliable guidance for efficient irrigation management.
5. Long-term simulations of site-specific irrigation management for Arizona cotton production. Engineering technologies are currently available for applying different irrigation rates at different locations in the field. However, further studies must identify cases where these technologies improve crop yield or save water. A comprehensive analysis of temporal weather patterns and spatial soil patterns was conducted by ARS researchers in Maricopa, Arizona. Assessments of irrigation requirements for cotton production among the different weather and soil patterns were performed. The results demonstrated little benefit for technologies that apply different rates of water at different spatial locations, because no improvements in crop yield or savings of water were shown as compared to spatially uniform irrigation management. Soils could hold enough water for weekly uniform irrigation management to sustain crop production at full potential. Field investigations are currently underway to verify the results of this simulation study and identify technologies that are most helpful for improving irrigation management. The research is particularly useful for growers who are considering options for technologies to improve water management on their farms and for researchers in the area of irrigation science.
6. Update to software for designing long-throated flumes. WinFlume is a software package for the design of long-throated flumes, devices that measure flow rate in open channels, and are essential for allocating water supplies to different water users and for managing on-farm water supplies. Long-throated flumes are widely used in the United States and worldwide due to their accuracy and low cost. ARS researchers in Maricopa, Arizona, developed many of the hydraulic relationships used for their design. At the request of US Bureau of Reclaimation, WinFlume1 was reprogrammed to address compatibility problems caused by the evolution in operating systems, and to provide with new functionalities. The new software, WinFlume 2, provides greater design guidance through a more intuitive user interface and an enhanced manual, and faulty procedures in the original software were identified and corrected. Users of WinFlume 2 include US Bureau of Reclamation and the USDA Natural Resource Conservation Service. Benefits will be better measurements of irrigation water flows, which in turn translates to water conservation.
Review Publications
Jimenez, J., Leiva, L., Cardoso, J.A., French, A.N., Thorp, K.R. 2020. Proximal sensing of Urochloa grasses increases selection accuracy. Crop and Pasture Science. 71(4):401-409. https://doi.org/10.1071/CP19324.
Ale, S., Omani, N., Himanshu, S.K., Bordovsky, J.P., Thorp, K.R., Barnes, E.M. 2020. Determining optimum irrigation termination periods for cotton production in the Texas High Plains. Transactions of the ASABE. 63(1):105-115. https://doi.org/10.13031/trans.13483.
Thorp, K.R., Marek, G.W., DeJonge, K.C., Evett, S.R., Lascano, R.J. 2019. Novel methodology to evaluate and compare evapotranspiration algorithms in an agroecosystem model. Journal of Environmental Modeling and Software. 199:214-227. https://doi.org/10.1016/j.envsoft.2019.06.007.
Huang, J., Scherer, L., Lan, K., Chen, F., Thorp, K.R. 2019. Advancing the application of a model-independent open-source geospatial tool for large spatiotemporal simulations. Environmental Modelling & Software. 119:374-378. https://doi.org/10.1016/j.envsoft.2019.07.003.
Bronson, K.F., Hunsaker, D.J., Meisinger, J.J., Rockholt, S.M., Thorp, K.R., Conley, M.M., Williams, C.F., Norton, E.R., Barnes, E.M. 2019. Improving nitrogen fertilizer use efficiency in subsurface drip-irrigated cotton in the desert southwest. Soil Science Society of America Journal. 83(6):1712-1721. https://doi.org/10.2136/sssaj2019.07.0210.
Thorp, K.R. 2019. Long-term simulations of site-specific irrigation management for Arizona cotton production. Irrigation Science. 38(1):49-64. https://doi.org/10.1007/s00271-019-00650-6.
DeJonge, K.C., Thorp, K.R., Marek, G.W. 2020. The apples and oranges of reference and potential evapotranspiration: Implications for agroecosystem models. Agricultural and Environmental Letters. 5(1). https://doi.org/10.1002/ael2.20011.
Bronson, K.F., Conley, M.M., Hunsaker, D.J., Thorp, K.R., French, A.N., Barnes, E.M. 2020. Which active optical sensor vegetation index is best for nitrogen assessment in irrigated cotton? Agronomy Journal. 112(3):2205-2218. https://doi.org/10.1002/agj2.20120.
Nelson, A.D., Ponciano, G.P., McMahan, C.M., Ilut, D.C., Pugh, N.A., Elshikha, D.E., Hunsaker, D.J., Pauli, D. 2019. Transcriptomic and evolutionary analysis of the mechanisms by which P. argentatum, a rubber producing perennial, responds to drought. Biomed Central (BMC) Plant Biology. 19:494. https://doi.org/10.1186/s12870-019-2106-2.
Puppo, L., Garcia, C., Bautista, E., Hunsaker, D.J., Beretta, A., Girona, J. 2019. Seasonal basal crop coefficient pattern of young non-bearing olive trees grown in drainage lysimeters in a temperate sub-humid climate. Agricultural Water Management. 226. https://doi.org/10.1016/j.agwat.2019.105732.
Chen, X., Thorp, K.R., van Oel, P., Xu, Z., Zhou, B., Li, Y. 2019. Environmental impact assessment of water-saving irrigation systems across 60 irrigation construction projects in northern China. Journal of Cleaner Production. 245. https://doi.org/10.1016/j.jclepro.2019.118883.
Huang, J., Ridoutt, B.G., Sun, Z., Lan, K., Thorp, K.R., Wang, X., Yin, X., Huang, J., Chen, F., Scherer, L. 2020. Balancing food production within the planetary water boundary. Journal of Cleaner Production. 253. https://doi.org/10.1016/j.jclepro.2019.119900.
Joshi, V.R., Thorp, K.R., Coulter, J.A., Johnson, G.A., Porter, P.M., Strock, J.S., Garcia Y Garcia, A. 2019. Improving site-specific maize yield estimation by integrating satellite multispectral data into a crop model. Agronomy. 9(11). https://doi.org/10.3390/agronomy9110719.
Thorp, K.R., Thompson, A.L., Bronson, K.F. 2020. Irrigation rate and timing effects on Arizona cotton yield, water productivity, and fiber quality. Agricultural Water Management. 234. https://doi.org/10.1016/j.agwat.2020.106146.
Zerihun, Z., Sanchez, C.A., Thorp, K.R., Hagler, M.J. 2019. Hydraulics of linear-move sprinkler irrigation systems, III: Model evaluation. Journal of Irrigation and Drainage Engineering. 8(2):1-11.
Huang, J., Ridoutt, B.G., Thorp, K.R., Wang, X., Lan, K., Liao, J., Tao, X., Wu, C., Huang, J., Chen, F., Scherer, L. 2019. Water-scarcity footprints and water productivities indicate unsustainable wheat production in China. Environmental Science and Technology. 224. https://doi.org/10.1016/j.agwat.2019.105744.
Luo, Z., Thorp, K.R., Abdel-Haleem, H.A. 2019. A high-throughput quantification of resin and rubber contents in Parthenium argentatum using near-infrared (NIR) spectroscopy. Plant Methods. 15. https://doi.org/10.1186/s13007-019-0544-3.
French, A.N., Hunsaker, D.J., Sanchez, C.A., Saber, M., Gonzalez, J.R., Anderson, R.G. 2020. Satellite-based NDVI crop coefficients and evapotranspiration with Eddy Covariance Validation for multiple durum wheat fields in the US Southwest. Agricultural Water Management. 239. https://doi.org/10.1016/j.agwat.2020.106266.
Wang, D.R., Venturas, M.D., Mackay, S.D., Hunsaker, D.J., Thorp, K.R., Gore, M.A., Pauli, D. 2020. Use of hydraulic traits for modeling genotype-specific acclimation in cotton under drought. New Phytologist. 228(3):898-909. https://doi.org/10.1111/nph.16751.
