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Global Water Security: Current Research and Priorities for Action
S. Ale, R. D. Harmel, A. P. Nejadhashemi, K. C. DeJonge, S. Irmak, I. Chaubey, K. R. Douglas-Mankin
Published in Transactions of the ASABE 63(1): 49-55 (doi: 10.13031/trans.13839). Copyright 2020 American Society of Agricultural and Biological Engineers.
Submitted for review in December 2019 as manuscript number NRES 13839; approved for publication in the Global Water Security Collection by the Natural Resources & Environmental Systems Community of ASABE in January 2020.
Mention of company or trade names is for description only and does not imply endorsement by the USDA. The USDA is an equal opportunity provider and employer.
The authors are Srinivasulu Ale, Associate Professor, Texas A&M AgriLife Research, Vernon, Texas; R. Daren Harmel, Director, USDA-ARS Center for Agricultural Resources Research, Fort Collins, Colorado; A. Pouyan Nejadhashemi, University Foundation Professor, College of Engineering, Michigan State University, East Lansing, Michigan; Kendall C. DeJonge, Research Agricultural Engineer, USDA-ARS Water Management and Systems Research Unit, Fort Collins, Colorado; Suat Irmak, Distinguished Professor, Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska; Indrajeet Chaubey, Dean, College of Agriculture, Health and Natural Resources, University of Connecticut, Storrs, Connecticut; Kyle R. Douglas-Mankin, Research Leader, USDA-ARS Water Management and Systems Research Unit, Fort Collins, Colorado. Corresponding author: Srinivasulu Ale, Texas A&M AgriLife Research, P.O. Box 1658, Vernon, TX 76385; phone: 940-552-9941; e-mail: sriniale@ag.tamu.edu.
Highlights
Abstract. This article introduces the Global Water Security collection in this issue of Transactions of the ASABE and issue 36(1) of Applied Engineering in Agriculture. Researchers, educators, industry partners, agricultural producers, and policymakers from 19 countries met at Hyderabad, India, to discuss critical issues and advancements at the Global Water Security Conference for Agriculture and Natural Resources. The conference was organized jointly by ASABE and the Indian Society of Agricultural Engineers (ISAE). This special collection consists of 13 articles selected from the 245 meeting presentations as well as invited articles. A perspectives article in this collection summarizes seven key priorities identified for action at the conference: reduce food waste, increase wastewater reuse, increase agricultural resiliency and efficiency, optimize irrigation efficiency and increase crop water productivity, improve water supply management, improve water resource infrastructure, and enhance water resource decision-making and policy formulation. The remaining 12 articles address a wide range of water security topics grouped by four themes: sustainable management of water resources (3 articles), limited irrigation for water conservation (5 articles), precision irrigation management (2 articles), and water management in hilly regions (2 articles). While these articles are not inclusive of all water security challenges in the agriculture and natural resources sectors, they highlight selected important challenges and potential solutions. The research presented in this special collection emphasizes the importance of developing and using appropriate location-specific technologies that increase water application efficiency and water use efficiency while maintaining adequate water supplies for natural resource functions and ecosystem services to ensure global water security.
The American Society of Agricultural and Biological Engineers (ASABE), in partnership with the Indian Society of Agricultural Engineers (ISAE), organized the Global Water Security Conference for Agriculture and Natural Resources on October 3-6, 2018, in Hyderabad, Telangana, India. This was the latest in a series of conferences resulting from ASABE’s Global Vision, implemented in 2012:
“ASABE will be among the global leaders that provide engineering and technological solutions toward creating a sustainable world with abundant food, water, and energy, and a healthy environment.”
Since its founding in 1907, ASABE has supported research and education and promoted solutions in food, agriculture, natural resources, and the environment. Today, our fast-growing global population, which is estimated to reach 9.7 billion by 2050 (UN, 2015), creates unprecedented challenges that will require innovative solutions. ASABE recognized the need to collaborate with other international organizations in addressing these challenges. Toward achieving ASABE’s Global Vision, three critical themes emerged for these challenges: food security, water security, and energy security, all in the context of sustainability and climate change. These three themes were explored in a report titled “Global partnerships for global solutions: An agricultural and biological engineering global initiative” (ASABE, 2015). In that report, ASABE identified specific goals and objectives related to food, water, and energy security. To bring together the international community, ASABE has been organizing a series of conferences focused on these three themes.
The first Global Initiative Conference, Engineering and Technology Innovation for Global Food Security, was convened on October 24-27, 2016, in Stellenbosch, South Africa. That conference brought together international academic, government, and industry experts from six continents to meet with local stakeholders and address the challenges of producing and providing safe and healthy food in a sustainable manner for the growing population. The Global Water Security Conference for Agriculture and Natural Resources was the second ASABE Global Initiative Conference. This 2018 international forum, which enabled non-traditional collaborations across agricultural, urban, industrial, and natural resource sectors along with public-private partnerships, was organized around three themes:
- Agricultural water scarcity and security: Weathering water resource extremes.
- Irrigation and drainage, conservation, and water management for sustainable agricultural growth.
- Identifying, managing, and treating conventional and alternative agricultural water supplies.
The ASABE/ISAE Global Water Security Conference for Agriculture and Natural Resources facilitated exchange of scientific ideas and technologies to address global water security issues in agroecosystems, explored transdisciplinary solutions to achieve water security from farm to global scales, and demonstrated successful water security innovations with some specific examples. This special collection is an important contribution resulting from the conference. It contains 13 articles from conference attendees and invited authors aimed at contributing toward long-term sustainable use of water for agricultural production and natural resources and improving agricultural productivity and water use efficiency. Each of these articles includes a discussion on implications for global water security and one or two statements in its abstract and conclusions connecting the research presented with the broad topic of global water security. The collection also contains a perspectives article (Harmel et al., 2020) that outlines recommendations to guide future research, technology development, public-private partnership, and policy formulations.
Perspectives on Global Water Security
Powerful words from the opening day of the Global Water Security Conference, such as “life-saving mission” and a “perfect storm threatening the world,” highlight the gravity of water scarcity around the world and the need for action to achieve global water security. According to Dr. Sonny Ramaswamy (former Director of the USDA National Institute of Food and Agriculture, currently President of the Northwest Commission on Colleges and Universities), the key causes for this “perfect storm” include the exploding human population, an increasing middle class and its changing dietary demands, climate change, globalization of trade, public mistrust of science, and the increasing costs of ensuring sustainability. The perspectives article (Harmel et al., 2020) synthesizes recurring themes and recommendations developed from the collective contributions of attendees and presenters at the conference to guide future research, extension education and outreach, technology development and transfer, public-private partnerships, and policy formulations. The article highlights seven key priorities for global water security: reduce food waste, increase wastewater reuse, increase agricultural resiliency and efficiency, optimize irrigation efficiency and increase crop water productivity, improve water supply management, improve water resource infrastructure, and enhance water resource decision-making and policy formulation.
A consistent theme throughout the conference was the need to fully integrate “non-technical” aspects into water resource science and engineering; these aspects are highlighted and discussed within each key priority. The authors acknowledge that although most water resource professionals are far more comfortable focusing on technical aspects, continuation of this narrow focus will likely prevent technical “solutions” from succeeding. Thus, the authors implore water resource professionals to: (1) commit to fully appreciating and considering the underlying non-technical threats to water security, (2) fully engage with all relevant players to ensure that interdisciplinary factors are understood and that socio-economic as well as region-specific policy considerations are adequately incorporated into proposed technical solutions, and (3) work together across all disciplines and across all boundaries to ensure global water security.
Research on Global Water Security
Water security is defined as the capacity of a population to safeguard sustainable access to adequate quantities of acceptable quality water for: (1) sustaining livelihoods, human well-being, and socio-economic development, (2) ensuring protection against waterborne pollution and diseases, and water-related disasters, and (3) preserving ecosystems in a climate of peace and political stability (UN, 2013). Because agriculture accounts for 70% of all freshwater withdrawals globally, effective and efficient water resources management at various landscape scales remains vitally important to enhance and sustain agricultural productivity (Irmak, 2015a). Adding to pressures on agricultural water use is an increased awareness of the instrumental value of water in maintaining environmental services and ecosystem resilience. According to a U.S. Intelligence Community Assessment, freshwater availability will not keep pace with increasing demand by 2040, in the absence of more effective water resource management (ICA, 2012). Limited availability of freshwater resources and deterioration of their quality threatens foreign relations and international security, as well as food production, public health, biodiversity, and energy generation. The number of water-related conflicts has increased dramatically in recent years, and strategies that improve water management and help reduce water-related conflicts are needed (Gleick, 2016).
Globally, many regions are facing increasing challenges related to water-limiting conditions as well as degradation of water quality, which make it more challenging to use existing water resources for irrigation and/or public consumption. Some regions are facing greater challenges than others. About two-thirds of the world’s population is exposed to high levels of water scarcity for at least one month of the year (Mekonnen and Hoekstra, 2016). Most of the developed world faces the challenge of reducing the water security threat to biodiversity while maintaining established water services for human needs. Therefore, a successful integrated water management system must consider strategies to ensure an adequate water supply for meeting agricultural production demands while protecting natural resources. Many presentations at the Global Water Security Conference revolved around the water security challenges described above. Several recommendations to address global water security emerged from the conference, and they were highlighted in a recent article in ASABE’s Resource magazine (Chaubey and Mani, 2019). The research articles in this special collection were grouped into the following four themes (table 1):
- Sustainable management of water resources.
- Limited irrigation for water conservation.
- Precision irrigation management.
- Water management in hilly regions.
The articles within each theme are discussed in the following sections.
Sustainable Management of Water Resources
Sustainable use of limited water resources for agricultural production requires improved understanding of crop water productivity in space and time; however, related socio-economic factors, such as gender perspectives and population shifts, must be considered in such technical components of regional and global water solutions (Kukal and Irmak, 2016a, 2016b). Chand et al. (2020) assessed water availability and agricultural water requirement to identify crops that are suitable for sustainable water use in the Bundelkhand region of India, which is facing acute water shortages. Results indicated that reverting to traditional crops, such as pearl millet, sesame, soybean, and chickpea, is more sustainable than growing cereal crops that have greater water requirements. The authors recommend incentives for increasing water use efficiency and water productivity with adoption of modern technologies, such as microirrigation based on consumptive water use, as well as adjusting cropping plans (cropping patterns or rotations) to optimize land and water resource allocation.
In another study of the Bundelkhand region of India, Padmaja et al. (2020) examined gender perspectives on water security. They used post-intervention data from semi-structured interviews in five villages to understand the benefits of watershed interventions aimed at enhancing agricultural drought resilience through groundwater recharge and agroforestry. The study assessed how women benefitted from the interventions and provided an understanding of the economic, social, and cultural barriers to women’s participation. Results showed that education is a significant factor related to female benefits of the interventions. The authors recommend development of mechanisms to empower all community members to participate in decision-making to ensure consideration of diverse local knowledge and to strengthen communities to become systematic and gender-sensitive institutions capable of building capacity to achieve water security.
Limited Irrigation for Water Conservation
Drought and/or limited water resources are major limiting factors for food and fiber production worldwide. Therefore, a substantial portion of the increase in crop water productivity (defined as the amount of crop produced per unit of input water) to meet the future food and fiber demands will most likely stem from irrigated agriculture (Irmak, 2015b). While irrigation increases the yields of most crops by 100% to 400% and contributes 40% of global food production on 20% of cultivated land (WWAP, 2014), water demand for agriculture is expected to increase by almost 20% to meet the increased food production demand by 2050 (WWAP, 2015). Thus, increasing the efficiency of water use and enhancing agricultural water productivity by adopting limited/deficit irrigation strategies is critical to achieving the dual goals of water and food security. Using the Decision Support System for Agrotechnology Transfer (DSSAT) Cropping System Model (CSM) CROPGRO-Cotton module, Ale et al. (2020) suggested optimum irrigation termination periods for cotton production in the Texas High Plains, which produces about a quarter of U.S. cotton. Irrigation termination is an important decision in cotton production, as early termination results in yield loss while late termination leads to loss of valuable irrigation water, delays harvest, and increases pest incidences. In normal-rainfall years, Ale et al. (2020) identified the first and second weeks of September (118 and 125 days after planting, respectively) as ideal irrigation termination periods for cotton under full and deficit irrigation, respectively. Terminating irrigation during these periods resulted in higher irrigation water use efficiency (defined as a ratio of the difference in irrigated and dryland yields, and the amount of seasonal irrigation) while maintaining higher crop yields. Compared to normal-rainfall years, ideal irrigation termination periods were found to be a week earlier in wet years and a week later in dry years. When used with field-specific, late-season information, the suggested guidelines will assist cotton producers in this region in making appropriate irrigation termination decisions for improving economic productivity of the rapidly depleting Ogallala Aquifer and thereby ensure water security for agriculture.
Projected climate change is expected to further exacerbate water availability and food security challenges by shrinking suitable agricultural areas, altering the growing season length, amplifying heat and water stresses, and increasing the incidence of diseases, pests, weeds, and soil erosion (Nearing et al., 2004; CIAT, 2011; Niang et al., 2014). Kothari et al. (2020) used projected climate data from nine global climate models in the DSSAT-CSM-CERES-Sorghum model and recommended 20% irrigation deficit as an ideal irrigation strategy for grain sorghum production under both current and future climatic conditions in the Texas High Plains. That strategy resulted in substantially higher irrigation water use efficiency than full irrigation with only a minor (<11%) yield loss. The authors found that irrigating during the early reproductive stages resulted in the most efficient use of limited water for grain sorghum production.
| Table 1. Summary of articles included in the 2020 ASABE Global Water Security Special Collection. | |||
| Authors | Theme | Region/Country | Article Title and Citation |
| R. D. Harmel, I. Chaubey, S. Ale, A. P. Nejadhashemi, S. Irmak, K. C. DeJonge, S. R. Evett, E. M. Barnes, M. Catley-Carlson, S. Hunt, and I. Mani | - | - | Perspectives on global water security, Transactions of the ASABE, 63(1), |
| P. Chand, R. Jain, S. Chand, P. Kishore, L. Malangmeih, and S. Rao | Sustainable management of water resources | Bundelkhand, India | Estimating water balance and identifying crops forsustainable use of water resources in the Bundelkhand region of India, Transactions of the ASABE, 63(1), https://doi.org/10.13031/trans.13429 |
| R. Padmaja, K. Kavitha, S. Pramanik, V. D. Duche, Y. U. Singh, A. M. Whitbread, R. Singh, K. Garg, and S. Leder | Sustainable management of water resources | Bundelkhand, India | Gender transformative impacts from watershed interventions: Insights from a mixed-methods study in the Bundelkhand region in India, Transactions of the ASABE, 63(1), https://doi.org/10.13031/trans.13568 |
| S. Ale, N. Omani, S. K. Himanshu, J. P. Bordovsky, K. R. Thorp, and E. M. Barnes | Limited irrigation for water conservation | Texas, U.S. | Determining optimum irrigation termination periods for cotton production in the Texas High Plains, Transactions of the ASABE, 63(1), https://doi.org/10.13031/trans.13483 |
| A. J. Schlegel, Y. Assefa, and D. O’Brien | Limited irrigation for water conservation | West-central Great Plains, U.S. | Productivity and profitability of four crop rotations under limited irrigation, Applied Engineering in Agriculture, 36(1), http://doi.org/10.13031/aea.13416 |
| R. Arun kumar, S. Vasantha, A. S. Tayade, S. Anusha, P. Geetha, and G. Hemaprabha | Limited irrigation for water conservation | Tamil Nadu, India | Physiological efficiency of sugarcane clones under water-limited conditions, Transactions of the ASABE, 63(1), https://doi.org/10.13031/trans.13550 |
| A. S. Tayade, S. Vasantha, R. Arun kumar, S. Anusha, R. Kumar, and G. Hemaprabha | Limited irrigation for water conservation | Tamil Nadu, India | Irrigation water use efficiency and water productivity of sugarcane commercial hybrids under water-limited conditions, Transactions of the ASABE, 63(1), https://doi.org/10.13031/trans.13548 |
| K. Kothari, S. Ale, J. P. Bordovsky, and C. L. Munster | Limited irrigation for water conservation | Texas, U.S. | Assessing the climate change impacts on grain sorghum yield and irrigation water use under full and deficit irrigation strategies, Transactions of the ASABE, 63(1), https://doi.org/10.13031/trans.13465 |
| S. R. Evett, S. A. O’Shaughnessy, M. A. Andrade, W. P. Kustas, M. C. Anderson, H. S. Schomberg, and A. Thompson | Precision irrigation management | U.S. | Precision agriculture and irrigation: Current U.S. perspectives, Transactions of the ASABE, 63(1), https://doi.org/10.13031/trans.13355 |
| K. C. DeJonge, H. Zhang, S. Taghvaeian, and T. J. Trout | Precision irrigation management | Colorado, U.S. | Canopy temperature bias from soil variability enhanced at high temperatures, Transactions of the ASABE, 63(1), https://doi.org/10.13031/trans.13554 |
| J. Singh, D. M. Heeren, D. R. Rudnick, W. E. Woldt, G. Bai, Y. Ge, and J. D. Luck | Precision irrigation management | Nebraska, U.S. | Soil structure and texture effects on the precision of soil water content measurements by a capacitance-based electromagnetic sensor Transactions of the ASABE, 63(1), https://doi.org/10.13031/trans.13496 |
| J. N. Khan, A. Jillani, S. R. Ali, and I. Ashraf | Water management in hilly regions | Ladakh, India | Application of RS/GIS in water conservation studies for water harvesting and groundwater harvesting in cold arid regions of northwestern Himalayas, Applied Engineering in Agriculture, 36(1), http://doi.org/10.13031/aea.13526 |
| V. Kumar and S. Sen | Water management in hilly regions | Uttarakhand, India | Assessment of spring potential for sustainable agriculture: A case study in lesser Himalayas, Applied Engineering in Agriculture, 36(1), http://doi.org/10.13031/aea.13520 |
Optimal selection of crops, hybrids, and crop rotations that maximize the efficiency of irrigation water use in local environments may enable global water security. Schlegel et al. (2020) compared two single-year cropping systems of continuous corn and grain sorghum, and two two-year rotations of corn-grain sorghum and corn-winter wheat in Kansas and found that the corn-grain sorghum rotation would be the most profitable cropping system under limited-irrigation conditions in the west-central U.S. Great Plains and similar environments. Similarly, Tayade et al. (2020) identified nine commercial sugarcane hybrids (out of 31 hybrids tested) that enhance water use efficiency and water productivity under deficit irrigation conditions based on a field experiment conducted at the Sugarcane Breeding Institute in Coimbatore, India. At the same site, Arun kumar et al. (2020) monitored physiological traits, such as canopy temperature depression, chlorophyll fluorescence, and soil-plant development, in addition to cane yield under full and deficit irrigation strategies and found that canopy temperature deficit and chlorophyll fluorescence are better physiological traits for screening sugarcane clones under limited irrigation. They also suggest six sugarcane hybrids for limited-irrigation conditions based on physiological traits and cane yield. With an average annual water requirement of about 2,000 mm, sugarcane is one of the highest water-using crops grown in India; therefore, selection of water-use-efficient hybrids could sustain sugarcane production in tropical Indian conditions while saving large quantities of irrigation water, thereby contributing to water security.
Precision Irrigation Management
Precision agriculture systems have not only become increasingly common but also increasingly complex. New technologies in computing power, data acquisition, data analysis and modeling, and spatial decision support have created tremendous opportunity while also presenting new challenges. Evett et al. (2020) provide a thorough overview of precision agricultural systems in this context and discuss new paradigms in precision agriculture. The power of information technology is imperative, but new data standards must be developed to take advantage of computing and data methods. Sensors and open-source hardware and software systems can identify plant stresses more accurately, quickly, at lower cost, and with lower power consumption than ever before, and transmission of data via wireless networks and smartphone technology is becoming ubiquitous. New opportunities exist in data acquisition above ground (e.g., unmanned aerial vehicles) and below ground (with low-cost soil sensor networks). While all these examples are relevant to irrigation management, decision support systems for precision irrigation applications lag behind other precision applications, presenting tremendous opportunities in this realm.
Canopy temperature is a responsive indicator of plant water status because plants become warmer under water stress as transpiration decreases. While this topic is discussed briefly by Evett et al. (2020), the effects of soil variability on canopy temperature are evaluated by DeJonge et al. (2020). In the framework of a maize deficit-irrigation experiment with multiple replicates, the authors illustrate how soil texture (characterized by electroconductivity) can bias canopy temperature measurements; this is most noticeable under increased irrigation deficits. That is, crops on coarser soils, which can hold less soil water, will reach stress more quickly, and thus have higher temperature than other areas with finer soils, even if they have received the same rainfall or irrigation amounts (e.g., at a mean canopy temperature of 35°C, the potential bias between replicates is up to 5°C). DeJonge et al. (2020) provide further linkages between soil and soil-water variability and outcomes of precision irrigation management.
While remote sensing systems show promise to help manage spatially variable irrigation, monitoring soil water content at various points and depths in the field remains important. This can be accomplished using soil-water sensors for continuous measurement. However, soil variability can present challenges in sensor calibration, which is explored in more depth by Singh et al. (2020). The authors evaluated the Meter Group S-1 capacitance-based sensor in both disturbed and undisturbed soils in two different soil textural classes. Their work found that undisturbed samples and laboratory calibration are preferable to disturbed samples and factory calibration, adding to the literature on the challenges in characterizing soil-water spatial variability.
Water Management in Hilly Regions
Limited availability of land for agriculture and erratic and inadequate rainfall pose major challenges for agriculture in mountainous regions. Kumar and Sen (2020) assessed the potential of spring discharge as an alternate source of irrigation water in the lesser Himalayan region of India and thereby contribute to achieving water security for agricultural production. They monitored a hillslope spring and estimated the water requirements of ten major crops by collecting rainfall and other weather variable data in the Algar River watershed in Tehri-Garhwal district of Uttarakhand state over two years. The authors suggest constructing storage tanks and/or trenches to collect excess spring water during the monsoon, and later using it during the crop growing season to improve crop yields and economic benefits. They also recommend using water saving methods, such as the System of Rice Intensification (SRI), and efficient irrigation systems, such as microirrigation, to further increase water productivity.
In another study in the cold and arid northwestern parts of the Himalayas in the Ladakh region in India, Khan et al. (2020) used remote sensing and geographic information system (GIS) based methods to assess the potential of water harvesting to counter the negative effects of spatiotemporal variability in precipitation on crop production. The authors integrated remote sensing, GIS, the analytical hierarchy process, and multi-criteria evaluation to map potential zones for harvesting rain and snowmelt and to identify suitable sites for constructing water harvesting structures to ensure water security for domestic, irrigation, and other uses.
Summary and Conclusions
The ASABE/ISAE Global Water Security Conference for Agriculture and Natural Resources was convened in 2018 at Hyderabad, India, to facilitate the exchange of scientific ideas and technologies to address global water security issues in agroecosystems, explore transdisciplinary solutions to achieve water security from farm to global scales, and demonstrate successful water security innovations. The conference was attended by 320 participants, including researchers, policymakers, producers, and other stakeholders from 19 countries. This special collection, which includes a perspective article and twelve research articles, identified seven key priorities for global water security and presented some examples of water security challenges and potential solutions. An important recommendation from the conference was to fully integrate “non-technical” aspects into water resource science and engineering, and for scientists and engineers to work together across disciplines to ensure global water security.
In view of the increasing demand and reduced availability of freshwater resources, there is a need to develop and implement strategies that promote sustainable use of water resources. Irrigated agriculture continues to play an important role in maintaining food security for the growing population. Adoption of water-use-efficient strategies, such as appropriate deficit/limited irrigation strategies, optimal selection and management of crops based on local conditions, and use of sensors for precision irrigation management, are critical components of efforts to achieve regional and global water security. In addition, alternative sources of water, such as springs in mountainous/karst regions, should be explored, and ways to enhance rainwater harvesting must be implemented. Furthermore, the impacts of climate change on crop yield and irrigation water use should be considered in devising irrigation management strategies. Advances in data acquisition, data analysis, and modeling should be used to develop decision support systems that aid in the management of water resources.
The recommendations made in the perspectives article and the results from the research studies included in this special collection provide guidance for future research, technology development, public-private partnership, and policy formulations for achieving global water security.
Acknowledgements
We wish to thank the authors of the articles in this Global Water Security special collection for their valuable contributions, and the ASABE publications staff and the reviewers for their timely management of the review and publication process. Major funding for this conference was provided by the USDA-NIFA (Award No. 2018-67021-27626). We also would like to thank numerous additional sponsors for supporting the Global Water Security Conference, and the chairs and members of various conference committees who contributed immensely to the success of the conference.
References
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. Trans. ASABE, 63(1), 105-115. https://doi.org/10.13031/trans.13483
Arun kumar, R., Vasantha, S., Tayade, A. S., Anusha, S., Geetha, P., & Hemprabha, G. (2020). Physiological efficiency of sugarcane clones under water-limited conditions. Trans. ASABE, 63(1), 133-140. http://doi.org/10.13031/trans.13550
ASABE. (2015). Global partnerships for global challenges: An agricultural and biological engineering global initiative. St. Joseph, MI: ASABE. Retrieved from https://www.asabe.org/Portals/0/PublicAffairs_Std/GlobalInitiative/globalinitiative.pdf
Chand, P., Jain, R., Chand, S., Kishore, P., Malangmeih, L., & Rao, S. (2020). Estimating water balance and identifying crops for sustainable use of water resources in the Bundelkhand region of India. Trans. ASABE, 63(1), 117-124. http://doi.org/10.13031/trans.13429
Chaubey, I., & Mani, I. (2019). Global water security conference for agriculture and natural resources: An ASABE Global Initiative conference. Resource, 26(3), 12-14. St. Joseph, MI: ASABE
CIAT. (2011). Future climate scenarios for Uganda’s tea growing areas. Cali, Columbia: International Center for Tropical Agriculture.
DeJonge, K. C., Zhang, H., Taghvaeian, S., & Trout, T. (2020). Canopy temperature bias from soil variability enhanced at high temperatures. Trans. ASABE, 63(1), 95-104. https://doi.org/10.13031/trans.13554
Evett, S. R., O’Shaughnessy, S. A., Andrade, M. A., Kustas, W. P., Anderson, M. C., Schomberg, H. S., & Thompson, A. (2020). Precision agriculture and irrigation: Current U.S. perspectives. Trans. ASABE, 63(1), 57-67. https://doi.org/10.13031/trans.13355
Gleick, P. H. (2016). Water strategies for the next administration. Science, 354(6312), 555-556. https://doi.org/10.1126/science.aaj2221
Harmel, R. D., Chaubey, I., Ale, S., Nejadhashemi, A. P., Irmak, S., DeJonge, K. C., ... Mani, I. (2020). Perspectives on global water security. Trans. ASABE, 63(1), 69-80. https://doi.org/10.13031/trans.13524
ICA. (2012). Global Water Security. Intelligence Community Assessment. Washington, DC: Office of the Director of National Intelligence. Retrieved from https://www.dni.gov/files/documents/Special%20Report_ICA%20Global%20Water%20Security.pdf
Irmak, S. (2015a). Interannual variation in long-term center pivot-irrigated maize evapotranspiration and various water productivity response indices: I. Grain yield, actual and basal evapotranspiration, irrigation-yield production functions, evapotranspiration-yield production functions, and yield response factors. J. Irrig. Drain. Eng., 141(5), 04014068. https://doi.org/10.1061/(ASCE)IR.1943-4774.0000825
Irmak, S. (2015b). Interannual variation in long-term center pivot-irrigated maize evapotranspiration (ET) and various water productivity response indices: II. Irrigation water use efficiency (IWUE), crop WUE, evapotranspiration WUE, irrigation-evapotranspiration use efficiency, and precipitation use efficiency. J. Irrig. Drain. Eng., 141(5), 04014069. http://doi.org/10.1061/(ASCE)IR.1943-4774.0000826
Khan, J. N., Jillani, A., Ali, S. R., & Ashraf, I. (2020). Application of RS/GIS in water conservation studies for water harvesting and groundwater harvesting in cold arid regions of northwestern Himalayas. Appl. Eng. Agric., 36(1), 105-114. http://doi.org/10.13031/aea.13526
Kothari, K., Ale, S., Bordovsky, J. P., & Munster, C. L. (2020). Assessing the climate change impacts on grain sorghum yield and irrigation water use under full and deficit irrigation strategies. Trans. ASABE, 63(1), 81-94. https://doi.org/10.13031/trans.13465
Kukal, M., & Irmak, S. (2016a). Long-term patterns of air temperatures, daily temperature range, precipitation, grass-reference evapotranspiration and aridity index in the USA Great Plains: Part I. Spatial trends. J. Hydrol., 542, 953-977. https://doi.org/10.1016/j.jhydrol.2016.06.006
Kukal, M., & Irmak, S. (2016b). Long-term patterns of air temperatures, daily temperature range, precipitation, grass-reference evapotranspiration and aridity index in the USA Great Plains: Part II. Temporal trends. J. Hydrol., 542, 978-1001. https://doi.org/10.1016/j.jhydrol.2016.06.008
Kumar, V., & Sen, S. (2020). Assessment of spring potential for sustainable agriculture: A case study in lesser Himalayas. Appl. Eng. Agric., 36(1), 11-24. http://doi.org/10.13031/trans.13520
Mekonnen, M. M., & Hoekstra, A. Y. (2016). Four billion people facing severe water scarcity. Sci. Adv., 2(2), e1500323. https://doi.org/10.1126/sciadv.1500323
Nearing, M. A., Pruski, F. F., & O’Neal, M. R. (2004). Expected climate change impacts on soil erosion rates: A review. J. Soil Water Cons., 59(1), 43-50.
Niang, I., Ruppel, O. C., Abdrabo, M. A., Essel, A., Lennard, C., Padgham, J., & Urquhart, P. (2014). Africa. In V. R. Barros, C. B. Field, D. J. Dokken, M. D. Mastrandrea, K. J. Mach, T. E. Bilir, ... L. L. White (Eds.), Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part B: Regional Aspects. Contribution of Working Group II to the Fifth Assessment Report of the IPCC. Cambridge, UK: Cambridge University Press.
Padmaja, R., Kavitha, K., Pramanik, S., Duche, V. D., Singh, Y.U., & Whitbread, A.M., ... Leder, S. (2020). Gender transformative impacts from watershed interventions: Insights from a mixed-methods study in the Bundelkhand region of India. Trans. ASABE, 63(1), 153-163. http://doi.org/10.13031/trans.13568
Schlegel, A. J., Assefa, Y., & O’Brien, D. (2020). Productivity and profitability of four crop rotations under limited irrigation. Appl. Eng. Agric., 36(1), 1-9. http://doi.org/10.13031/aea.13416
Singh, J., Heeren, D. M., Rudnick, D. R., Woldt, W. E., Bai, G., Ge, Y., & Luck, J. D. (2020). Soil structure and texture effects on the precision of soil water content measurements by a capacitance-based electromagnetic sensor. Trans. ASABE, 63(1), 141-152. http://doi.org/10.13031/trans.13496
Tayade, A. S., Vasantha, S., Arun kumar, R., Anusha, S., Kumar, R., & Hemprabha, G. (2020). Irrigation water use efficiency and water productivity of sugarcane commercial hybrids under water-limited conditions. Trans. ASABE, 63(1), 125-132. http://doi.org/10.13031/trans.13548
UN. (2013). Water security and the global water agenda. Geneva, Switzerland: UN-Water. Retrieved from https://www.unwater.org/publications/water-security-global-water-agenda/
UN. (2015). World population prospects: 2015 revision. New York, NY: United Nations, Department of Economic and Social Affairs. Retrieved from https://population.un.org/wpp/Publications/Files/WPP2015_DataBooklet.pdf
WWAP. (2014). The United Nations World Water Development Report 2014: Water and energy. Paris, France: UNESCO. Retrieved from https://www.unwater.org/publications/world-water-development-report-2014-water-energy/
WWAP. (2015). The United Nations World Water Development Report 2015: Water for a sustainable world. Paris, France: UNESCO. Retrieved from http://www.unesco.org/new/en/natural-sciences/environment/water/wwap/wwdr/2015-water-for-a-sustainable-world/