scholarly journals Past, Present, and Future of Irrigation on the U.S. Great Plains

2020 ◽  
Vol 63 (3) ◽  
pp. 703-729 ◽  
Author(s):  
Steven R. Evett ◽  
Paul D. Colaizzi ◽  
Freddie R. Lamm ◽  
Susan A. O’Shaughnessy ◽  
Derek M. Heeren ◽  
...  

Highlights Irrigation is key to the productivity of Great Plains agriculture but is threatened by water scarcity. The irrigated area grew to >9 million ha since 1870, mostly since 1950, but is likely to decline. Changes in climate, water availability, irrigated area, and policy will affect productivity. Adaptation and innovation, hallmarks of Great Plains populations, will ensure future success. Abstract. Motivated by the need for sustainable water management and technology for next-generation crop production, the future of irrigation on the U.S. Great Plains was examined through the lenses of past changes in water supply, historical changes in irrigated area, and innovations in irrigation technology, management, and agronomy. We analyzed the history of irrigated agriculture through the 1900s to the present day. We focused particularly on the efficiency and water productivity of irrigation systems (application efficiency, crop water productivity, and irrigation water use productivity) as a connection between water resource management and agricultural production. Technology innovations have greatly increased the efficiency of water application, the productivity of water use, and the agricultural productivity of the Great Plains. We also examined the changes in water stored in the High Plains aquifer, which is the region’s principle supply for irrigation water. Relative to other states, the aquifer has been less impacted in Nebraska, despite large increases in irrigated area. Greatly increased irrigation efficiency has played a role in this, but so have regulations and the recharge to the aquifer from the Nebraska Sand Hills and from rivers crossing the state. The outlook for irrigation is less positive in western Kansas, eastern Colorado, and the Oklahoma and Texas Panhandles. The aquifer in these regions is recharged at rates much less than current pumping, and the aquifer is declining as a result. Improvements in irrigation technology and management plus changes in crops grown have made irrigation ever more efficient and allowed irrigation to continue. There is good reason to expect that future research and development efforts by federal and state researchers, extension specialists, and industry, often in concert, will continue to improve the efficiency and productivity of irrigated agriculture. Public policy changes will also play a role in regulating consumption and motivating on-farm efficiency improvements. Water supplies, while finite, will be stretched much further than projected by some who look only at past rates of consumption. Thus, irrigation will continue to be important economically for an extended period. Sustaining irrigation is crucial to sustained productivity of the Great Plains “bread basket” because on average irrigation doubles the efficiency with which water is turned into crop yields compared with what can be attained in this region with precipitation alone. Lessons learned from the Great Plains are relevant to irrigation in semi-arid and subhumid areas worldwide. Keywords: Center pivot, Crop water productivity, History, Sprinkler irrigation, Subsurface drip irrigation, Water use efficiency.

2019 ◽  
Vol 62 (4) ◽  
pp. 985-1002
Author(s):  
Narayanan Kannan ◽  
Sujoy B. Roy ◽  
John S. Rath ◽  
Carrie S. Munill ◽  
Robert A. Goldstein

Abstract. Water consumption for crop irrigation is the largest single use of water in the U.S. but is poorly quantified because of limitations in data and the inherent challenges in measuring water consumption. In this study, water consumption for irrigated agriculture was estimated across the U.S. to improve understanding of water budgets in different regions. Published data on cropping patterns and water application were used in conjunction with a national-scale analysis to estimate water application and crop water consumption using the SWAT (Soil and Water Assessment Tool) watershed model. Crop water consumption estimates were based on evapotranspiration, with supporting information on the diversity of crops, irrigated area, water quantity and source, and local weather conditions. Quantification of water consumption supports broader analyses of the food-energy-water nexus and allows evaluation of the efficiency of irrigation water use at different spatial scales. Focusing on 2005 data, it is estimated that 60% of water reported as withdrawn from various sources is applied to fields, indicating a potentially large and poorly understood conveyance loss that occurs in a small number of states. Of the field-applied irrigation water, roughly 65% is directly used by crops or is lost in the field, with large regional variations. This may be compared to consumption estimates in prior studies that ranged from 16% to 90%. Areas that dominate the national aggregate estimate of crop water consumption include California’s Central and Imperial Valleys, areas overlying the Ogallala Aquifer in the central U.S., the Lower Colorado Basin, and the eastern part of the Pacific Northwest Basin. Keywords: Crop water use, Irrigated agriculture, SWAT, Watershed model, Water withdrawal.


2020 ◽  
Vol 36 (4) ◽  
pp. 457-478
Author(s):  
Edward M Barnes ◽  
B. Todd Campbell ◽  
George Vellidis ◽  
Wesley Porter ◽  
Jose Payero ◽  
...  

Highlights Over the last 40 years the amount of irrigation water used by cotton in the United States has decreased while yields have increased leading to a large increase in crop water productivity (CWP). Many factors have contributed to improved CWP, such as improvements in water delivery systems. Irrigation scheduling technologies have also contributed to improved CWP; however, farmer adoption of advanced scheduling technologies is still limited and there is significant room for improvement. Increased yields from improved cultivars without an increase in water requirements has also been important for CWP. Continued developments in sensor technologies and improved crop simulation models are two examples of future strategies that should allow the U.S. cotton industry to continue an upward trend in CWP. Abstract. Over the last 40 years the amount of irrigation water used by cotton in the United States has decreased while yields have increased. Factors contributing to higher water productivity and decreased irrigation water use include migration of cotton out of the far western U.S. states to the east where more water requirements are met by rainfall; improved irrigation delivery systems with considerable variation in types and adoption rates across the U.S.; improved irrigation scheduling tools; improved genetics and knowledge of cotton physiology, and improved crop models that can help evaluate new irrigation strategies rapidly and inexpensively. The considerable progress over the last 40 years along with the promise of emerging technologies suggest that this progress will continue. Keywords: Cotton, Crop water productivity, Irrigation, Sustainability, Water use efficiency.


2021 ◽  
Vol 64 (1) ◽  
pp. 287-298
Author(s):  
Ruixiu Sui ◽  
Jonnie Baggard

HighlightsWe developed and evaluated a variable-rate irrigation (VRI) management method for five crop years in the Mississippi Delta.VRI management significantly reduced irrigation water use in comparison with uniform-rate irrigation (URI). There was no significant difference in grain yield and irrigation water productivity between VRI and URI management.Soil apparent electrical conductivity (ECa) was used to delineate irrigation management zones and generate VRI prescriptions.Sensor-measured soil water content was used in irrigation scheduling.Abstract. Variable-rate irrigation (VRI) allows producers to site-specifically apply irrigation water at variable rates within a field to account for the temporal and spatial variability in soil and plant characteristics. Developing practical VRI methods and documenting the benefits of VRI application are critical to accelerate the adoption of VRI technologies. Using apparent soil electrical conductivity (ECa) and soil moisture sensors, a VRI method was developed and evaluated with corn and soybean for five crop years in the Mississippi Delta. Soil ECa of the study fields was mapped and used to delineate VRI management zones and create VRI prescriptions. Irrigation was scheduled using soil volumetric water content measured by soil moisture sensors. A center pivot VRI system was employed to deliver irrigation water according to the VRI prescription. Grain yield, irrigation water use, and irrigation water productivity in the VRI treatment were determined and compared with that in a uniform-rate irrigation (URI) treatment. Results showed that the grain yield and irrigation water productivity between the VRI and URI treatments were not statistically different with both corn and soybean crops. The VRI management significantly reduced the amount of irrigation water by 22% in corn and by 11% in soybean (p = 0.05). Adoption of VRI management could improve irrigation water use efficiency in the Mississippi Delta. Keywords: Soil electrical conductivity, Soil moisture sensor, Variable rate irrigation, Water management.


2017 ◽  
Author(s):  
◽  
Akinola Mayowa Ikudayisi

Water is an essential natural resource for human existence and survival on the earth. South Africa, a water stressed country, allocates a high percentage of its available consumptive water use to irrigation. Therefore, it is necessary that we optimize water use in order to enhance food security. This study presents the development of mathematical models for irrigation scheduling of crops, optimal irrigation water release and crop yields in Vaal Harts irrigation scheme (VIS) of South Africa. For efficient irrigation water management, an accurate estimation of reference evapotranspiration (ETₒ) should be carried out. However, due to non-availability of enough historical data for the study area, mathematical models were developed to estimate ETₒ. A 20-year monthly meteorological data was collected and analysed using two data–driven modeling techniques namely principal component analysis (PCA) and adaptive neuro-fuzzy inference systems (ANFIS). Furthermore, an artificial neural network (ANN) model was developed for real time prediction of future ETₒ for the study area. The real time irrigation scheduling of potatoes was developed using a crop growth simulation model called CROPWAT. It was used to determine the crop water productivity (CWP), which is a determinant of the relationship between water applied and crop yield. Finally, a new and novel evolutionary multi-objective optimization algorithm called combined Pareto multi-objective differential evolution (CPMDE) was applied to optimize irrigation water use and crop yield on the VIS farmland. The net irrigation benefit, land area and irrigation water use of maize, potatoes and groundnut were optimized. Results obtained show that ETₒ increases with temperature and windspeed. Other variables such as rainfall and relative humidity have less significance on the value of ETₒ. Also, ANN models with one hidden layer showed better predictive performance compared with other considered configurations. A 5-day time step irrigation schedule data and graphs showing the crop water requirements and irrigation water requirements was generated. This would enable farmers know when, where, and how much water to apply to a given farmland. Finally, the employed CPMDE optimization algorithm produced a set of non-dominated Pareto optimal solutions. The best solution suggests that maize, groundnut and potatoes should be planted on 403543.44 m2, 181542.00 m2 and 352876.05 m2areas of land respectively. This solution generates a total net benefit of ZAR 767,961.49, total planting area of 937961.49 m2 and irrigation water volume of 391,061.52 m3. Among the three crops optimized, maize has the greatest land area, followed by potatoes and groundnut. This shows that maize is more profitable than potatoes and groundnut with respect to crop yield and water use in the study area.


Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 888 ◽  
Author(s):  
Christoph Studer ◽  
Simon Spoehel

Appropriate irrigation scheduling for efficient water use is often a challenge for small-scale farmers using drip irrigation. In a trial with 12 farmers in Sébaco, Nicaragua, two tools to facilitate irrigation scheduling were tested: the Water Chart (a table indicating required irrigation doses) and tensiometers. The study aimed at evaluating if and to what extent simple tools can reduce irrigation water use and improve water productivity in drip-irrigated vegetable (beetroot; Beta vulgaris L.) production compared with the farmers’ usual practice. Irrigation water use was substantially reduced (around 20%) when farmers irrigated according to the tools. However, farmers did not fully adhere to the tool guidance, probably because they feared that their crop would not get sufficient water. Thus they still over-irrigated their crop: between 38% and 88% more water than recommended was used during the treatment period, resulting in 91% to 139% higher water use than required over the entire growing cycle. Water productivity of beetroot production was, therefore, much lower (around 3 kg/m3) than what can be achieved under comparable conditions, although yields were decent. Differences in crop yield and water productivity among treatments were not significant. The simplified Water Chart was not sufficiently understandable to farmers (and technicians), whereas tensiometers were better perceived, although they do not provide any indication on how much water to apply. We conclude that innovations such as drip irrigation or improved irrigation scheduling have to be appropriately introduced, e.g., by taking sufficient time to co-produce a common understanding about the technologies and their possible usefulness, and by ensuring adequate follow-up support.


2017 ◽  
Vol 60 (4) ◽  
pp. 1189-1208 ◽  
Author(s):  
Meetpal S. Kukal ◽  
Suat Irmak

Abstract. Sustainable agricultural utilization of the limited water resources demands improvements in understanding the changes in crop water productivity (CWP) in space and time, which is often presented as a potential solution to relieve the growing pressure on fresh water resources. In addition, crop yield needs to be studied in relation to precipitation received annually and during the growing season for its contribution to reduce irrigation water requirements, which is quantified through precipitation use efficiency (PUE). Hence, systematic quantifications, mapping, and analyses of large-scale CWP and PUE levels are needed. This study aims to quantify long-term (1982-2013) information on grain yield, PUE, and CWP for maize and soybean in the U.S. Great Plains counties and to map and analyze them. Multiple public data sources were used, including weather, satellite, and yield datasets for the 834 counties over a 32-year period. Long-term average maize grain yield ranged from 1.56 to 12.81 t ha-1 with a regional average of 6.66 t ha-1. Long-term average soybean grain yield ranged from 0.47 to 3.46 t ha-1 with an average of 2.17 t ha-1. About 87% and 89% of the counties in the region showed increasing trends in grain yield for maize and soybean, respectively, with regional average increasing trends for maize and soybean yield of 0.1014 and 0.0328 t ha-1 year-1, respectively. The regional annual PUE (ANNPUE) and growing season PUE (GRSPUE) were 1.09 and 1.90 kg m-3, respectively, for maize and 0.32 and 0.55 kg m-3, respectively, for soybean. In addition, the regional average increasing trends in maize ANNPUE (exhibited by 88% of counties) and GRSPUE (exhibited by 85% of counties) were 0.0174 and 0.0316 kg m-3 year-1. For soybean, regional average increasing trends in ANNPUE (exhibited by 91% of counties) and GRSPUE (exhibited by 87% of counties) were 0.0048 and 0.0081 kg m-3 year-1. The magnitude of maize CWP varied from 0.30 to 2.97 kg m-3 with a regional average of 1.08 kg m-3, and soybean CWP varied from 0.15 to 0.67 kg m-3 with a regional average of 0.40 kg m-3. It was found that 79% and 86% of the counties showed positive trends in maize and soybean CWP, respectively, and the increasing trend magnitudes were 0.0144 and 0.0047 kg m-3 year-1. Pooled data from all counties and growing seasons were used to develop frequency distribution histograms to quantify the inter-annual variation and distribution characteristics. The level of CWP variability represented via maps revealed regions where opportunity exists for improvements in production system efficiency. A comprehensive understanding of the spatial and temporal patterns in these efficiency indices will provide a basis for decision-making in resource assessments, planning, evaluation, and investment by state and federal agencies and stakeholders. Keywords: Agriculture, Climate, Evapotranspiration, Great Plains, Water productivity.


2016 ◽  
Vol 8 (3) ◽  
pp. 112 ◽  
Author(s):  
David K. Rop ◽  
Emmanuel C. Kipkorir ◽  
John K. Taragon

<p>The broad objective of this study was to test Deficit Irrigation (DI) as an appropriate irrigation management strategy to improve crop water productivity and give optimum onion crop yield. A field trial was conducted with drip irrigation system of six irrigation treatments replicated three times in a randomized complete block design. The crop was subjected to six water stress levels 100% ETc (T100), 90% ETc (T90), 80% ETc (T80), 70% ETc (T70), 60% ETc (T60) and 50% ETc (T50) at vegetative and late season growth stages. The onion yield and quality based on physical characteristics and irrigation water use efficiency were determined. The results indicated that the variation in yield ranged from 34.4 ton/ha to 18.9 ton/ha and the bulb size ranged from 64 mm to 35 mm in diameter for T100 and T50 respectively. Irrigation water use efficiency values decreased with increasing water application level with the highest of 16.2 kg/ha/mm at T50, and the lowest being13.1 kg/ha/mm at T100. It was concluded that DI at vegetative and late growth stages influence yields in a positive linear trend with increasing quantity of irrigation water and decreasing water stress reaching optimum yield of 32.0 ton/ha at 20% water stress (T80) thereby saving 10.7% irrigation water. Onion bulb production at this level optimizes water productivity without significantly affecting yields. DI influenced the size and size distribution of fresh onion bulbs, with low size variation of the fresh bulbs at T80.</p>


2016 ◽  
Vol 65 (1-2) ◽  
pp. 53-59
Author(s):  
Borivoj Pejić ◽  
Ksenija Mačkić ◽  
Srdjan Pavković ◽  
Branka Ljevnaić-Mašić ◽  
Miroljub Aksić ◽  
...  

Summary The objective of the study, conducted in Vojvodina a northern part of the Serbia Republic, was to analyse the effect of drip irrigation on yield, evapotranspiration and water productivity of watermelon (Cirullus lanatus Thunb.) grown with plasticulture. Irrigation was scheduled on the basis of water balance method. Daily evapotranspiration was computed using the reference evapotranspiration and crop coefficient. The yield of watermelon in irrigation conditions (37,28 t/ha) was significantly higher compared to non irrigated (9,98 t/ha). Water used on evapotranspiration in irrigation conditions was 398 mm and 117 mm on non irrigated variant. The crop yield response factor of 1,04 for the whole growing season reveals that relative yield decrease was nearly equal to the rate of evapotranspiration deficit. The values of irrigation water use efficiency and evapotranspiration water use efficiency were 9,93 kg/m3 and 10,29 kg/m3 respectively. The determined results could be used as a good platform for watermelon growers in the region, in terms of improvement of the optimum utilization of irrigation water.


2021 ◽  
Vol 13 (2) ◽  
pp. 677-685
Author(s):  
O. P. Singh ◽  
P. K. Singh

With the growing irrigation water scarcity, the researchers and policymakers are more concerned to improve the irrigation water use efficiency at farmers’ field level. The water-saving technologies provide greater control over water delivery to the crop root zone and reduce the non-beneficial evaporation from the crop field. Water productivity is an important concept for measuring and comparing water use efficiency. The present study tried to estimate the irrigation water use and physical water productivity of cotton under alternate furrow and drip irrigation methods in the Bhavnagar district of Gujarat. Results suggest that crop yield and physical water productivity were higher for cotton irrigated by drip method than alternate furrow method during normal rainfall and drought year. The irrigation water use under the drip method of irrigation was lower as compared to the alternate furrow method. In the case of total water (effective rainfall + irrigation water) use, per hectare crop yield and physical water productivity were higher for the drip method of irrigation than the alternate furrow method of irrigating cotton crop during normal rainfall and drought year. In the case of total water use (effective rainfall + irrigation water), it was lower for drip irrigation than the alternate furrow method of irrigating cotton crop during normal rainfall year and drought year. While estimating total water (effective rainfall + irrigation water) use, it was assumed that there is no return flow of water from the cotton field in the study area under both irrigation methods.


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