Sustainable Management and Regulation of Agricultural Water Resources in the Context of Global Climate Change

Water is the lifeblood of agriculture, a sector that sustains global food security and livelihoods. However, the increasing complexity of water management in agriculture, exacerbated by global climate change, poses significant challenges to the sustainability of this vital resource. Specifically, climate change has intensified the risks associated with agricultural water management, particularly in regions already grappling with water scarcity [1]. While certain aspects of climate change, such as increased precipitation and elevated CO₂ concentrations, may offer localized benefits, the overarching impacts—reduced water availability, more frequent extreme weather events, and shifting precipitation patterns—threaten agricultural productivity and water security. Moreover, as the global population continues to grow, the demand for food and water is increasing, placing additional pressure on already strained water resources [2]. In addition, climate change exacerbates these pressures by altering precipitation patterns, increasing the frequency and severity of extreme weather events, and raising temperatures, all of which impact agricultural water use [3]. Consequently, in regions where water scarcity is already a concern, these changes pose significant economic and social challenges. Despite some localized benefits, the overall impact of climate change on agricultural water management is overwhelmingly negative, necessitating the development of robust adaptation strategies [4].

In this context, developing adaptation strategies through sustainable water management and regulation is not just a necessity but an imperative. Therefore, this Special Issue seeks to advance our understanding of the risks and adaptation strategies in agricultural water management, with the goal of enhancing the efficient use of limited water resources and ensuring food security in a changing climate. To achieve this, this Special Issue aims to address these challenges by exploring historical and future trends in crop evapotranspiration and irrigation requirements, evaluating the effectiveness of various agronomic and policy measures, and proposing sustainable pathways for adapting to future climate change. Ultimately, the goal is to enhance our understanding of the risks and opportunities associated with agricultural water management under climate change and to provide policymakers with the knowledge needed to formulate effective strategies for reducing the vulnerability of the agricultural sector and increasing its resilience. As a result, we can better prepare for the impacts of climate change and ensure the continued availability of water resources for agricultural production, thereby safeguarding global food security and livelihoods.

In the first paper of this Special Issue, Yunquan Zhang and Peiling Yang discuss a simulation-based optimization model for controlling soil salinization in the Hetao irrigation district in northwest China. Their results provide water shortage and water distribution targets for multiple water sources and levels across five irrigation areas in the HID. These targets were used as the main input parameters for the SALTMOD model, which is based on the principle of water and salt balance. The outputs included data on groundwater mineralization and depth. Their findings revealed that (1) integrated interval two-stage robust stochastic programming and the SALTMOD model can be coupled to simulate a model under uncertainty; (2) systemic risk issues were effectively considered; and (3) the proposed method can be applied to the HID to address soil salinization control. This approach is particularly applicable to arid and semiarid regions facing similar challenges (Contribution 1). Similarly, Pan Li, Wen Yin, Guiping Chen, Yao Guo, Zhilong Fan, Falong Hu, Fuxue Feng, Hong Fan, and Wei He conducted a comprehensive evaluation of yield, resource utilization efficiency, carbon emissions, and economic benefits based on the crop rotation of maize with different wheat straw-returning methods. They concluded that no tillage with 25–30 cm tall wheat straw mulching is a sustainable maize management practice for increasing economic benefits and improving environmental impacts in arid irrigated areas (Contribution 2). This finding highlights the importance of adopting conservation agriculture practices to enhance sustainability in water-scarce regions.

In another study, Xin Zhang, Jianheng Zhang, Jiaxin Xue, and Guiyan Wang confirmed that the S086 variety, combined with a total irrigation water amount of 165 mm, could achieve the dual goals of high crop yields and water use efficiency, thereby reducing groundwater depletion (Contribution 3). This research underscores the potential of crop breeding and precision irrigation technologies to optimize water use in agriculture. Furthermore, Vinod Phogat, Jirka Šimůnek, Paul Petrie, Tim Pitt, and Vilim Filipović used a process-based biophysical numerical model to evaluate water balance and nitrogen (N) dynamics in soils under rainfed wheat cultivation at low- (219 mm, Pygery) and medium-rainfall (392 mm, Yeelanna) sites in South Australia over two seasons. Their results suggest that combining water balance and N modeling can optimize wheat production while minimizing N losses in rainfed agriculture (Contribution 4). This approach provides a valuable tool for managing water and nutrient resources in rainfed systems, which are particularly vulnerable to climate variability. Additionally, Ahmed A. Abdelmoneim, Roula Khadra, Angela Elkamouh, Bilal Derardja, and Giovanna Dragonetti investigated the field validation of a low-cost IoT soil moisture tensiometer prototype, comparing weather-based irrigation to soil moisture-based irrigation in terms of yield and crop water productivity. They noted that while the sensors were deployed for two months during the lettuce crop season, further investigation is needed to assess their long-term reliability and maintenance requirements (Contribution 5). This study not only highlights the potential of IoT-based technologies to improve irrigation efficiency but also emphasizes the need for robust and durable sensor systems.

In another significant contribution, Waqas Ahmed, Suhail Ahmed, Jehangir F. Punthakey, Ghulam Hussain Dars, Muhammad Shafqat Ejaz, Abdul Latif Qureshi, and Michael Mitchell used MODFLOW 2005 to quantify the groundwater budget of the Northern Rohri Canal Command Area under RCP 4.5 and 8.5 climatic scenarios. Their estimates suggest that a sustainable yield of approximately 3 ± 0.3 BCM per year should be maintained to ensure adaptive groundwater reserves during droughts while reducing waterlogging impacts (Contribution 6). This research provides critical insights for managing groundwater resources in regions facing both water scarcity and waterlogging. Moreover, Natalia Julio, Amaya Álvez, Rodrigo Castillo, Kimberly Iglesias, Diego Rivera, Fernando Ochoa, and Ricardo Figueroa analyzed legal approaches and management mechanisms in Chile, highlighting the need for River Basin Boards with broader planning powers to incorporate diverse stakeholders and improve water governance (Contribution 7). Their findings underscore the importance of inclusive and adaptive governance structures for managing water resources in a changing climate. In a different context, Krzysztof Kud, Aleksandra Badora, and Marian Woźniak used a diagnostic survey method in southeastern Poland to assess the social awareness of water management under climate change. Their findings revealed a lack of awareness about natural water retention methods, with respondents favoring outdated technical solutions like flood embankments and large dams (Contribution 8). This study highlights the need for public education and engagement to promote sustainable water management practices.

Additionally, Edson Costa-Filho, José L. Chávez, and Huihui Zhang evaluated remote sensing (RS) algorithms for estimating maize evapotranspiration (ETa) in semiarid regions. They found that the MSR5 proximal platform provided optimal data, emphasizing the need to improve RS data quality from sub-optimal platforms for sustainable irrigation management (Contribution 9). This research not only demonstrates the potential of remote sensing technologies to enhance irrigation efficiency but also calls for advancements in data quality and accessibility. Finally, Andrzej Brandyk, Ryszard Oleszczuk, Grzegorz Majewski, Mariusz Barszcz, and Katarzyna Rozbicka present a conceptual model for managing drainage/irrigation systems, which demonstrates close alignment with Modflow simulations and offers potential for calibration in polder areas (Contribution 10). This model provides a practical tool for managing water resources in low-lying agricultural areas, which are particularly vulnerable to flooding and waterlogging.

Climate change is expected to have profound impacts on agricultural water management, particularly in regions that are already water-stressed. One of the most significant impacts is the alteration in precipitation patterns, which can lead to both increased drought frequency and more intense rainfall events. These changes can reduce water availability for irrigation, increase the risk of crop failure, and exacerbate soil erosion. Additionally, higher temperatures can elevate evapotranspiration rates, further straining water resources. The Intergovernmental Panel on Climate Change (IPCC) has projected that water availability will decline in many regions, particularly in the subtropics and mid-latitude areas [1]. For example, in the Mediterranean region, water availability is expected to decrease by 20–30% by the end of the century, threatening the productivity of water-intense crops like rice and cotton [5]. Furthermore, extreme weather events such as droughts, floods, and heatwaves are becoming more frequent and severe, leading to crop failures, soil degradation, and economic losses. For instance, the 2012 drought in the United States caused significant reductions in corn and soybean yields [6], while the 2010 Russian heatwave reduced wheat production by 30%, contributing to a global spike in food prices [7].

In addition to these direct impacts, climate change also affects water quality, further complicating agricultural water management. For example, higher temperatures can increase the growth of harmful algae in water bodies [8], while more intense rainfall events can lead to the increased runoff of agricultural chemicals into water sources [9]. These changes not only reduce the availability of clean water for irrigation but also pose risks to human health and ecosystems. Moreover, climate change is expected to exacerbate existing inequalities in water access. In many developing countries, smallholder farmers, who rely heavily on rainfed agriculture, are particularly vulnerable to changes in precipitation patterns and water availability [10]. Without adequate adaptation measures, these farmers face increased risks of crop failure, food insecurity, and poverty.

To address these challenges, a multi-faceted approach is needed, combining technological innovation, policy interventions, and community engagement. Technological solutions, such as precision irrigation, drought-resistant crop varieties, and remote sensing technologies, can enhance water use efficiency and reduce the vulnerability of agricultural systems to climate variability [11]. Policy measures, such as water pricing, subsidies for water-saving technologies, and integrated water resources management, can incentivize sustainable water use and ensure equitable access to water resources. Community engagement and education are also critical for promoting sustainable water management practices and building resilience at the local level [12].

Looking ahead, there are several key areas where further research and innovation are needed to address the challenges of agricultural water management under climate change. First, there is a need for more accurate and localized climate projections to inform water management decisions. Second, research is needed to develop and scale up innovative technologies, such as smart irrigation systems, drought-tolerant crops, and water-efficient farming practices. Third, there is a need for more integrated approaches for water management that consider the interconnectedness of water, food, energy, and ecosystems. Finally, there is a need for greater collaboration and knowledge sharing among researchers, policymakers, farmers, and other stakeholders to ensure that adaptation strategies are effective, inclusive, and sustainable. By addressing these research gaps and fostering collaboration across sectors, we can build a more resilient and sustainable agricultural system that is capable of meeting the challenges of a changing climate and ensuring food security for all.

In conclusion, climate change poses significant challenges to agricultural water management, particularly in water-stressed regions. However, by adopting advanced irrigation technologies, implementing water-saving agronomic practices, and developing policies that promote sustainable water management, it is possible to enhance the resilience of agricultural systems and reduce their vulnerability to climate change. This Special Issue contributes to this goal by exploring historical and future trends in crop evapotranspiration and irrigation requirements, evaluating the effectiveness of various agronomic and policy measures, and proposing sustainable pathways for adaptation. By enhancing our understanding of the risks and opportunities associated with agricultural water management under climate change, we can develop more effective strategies to ensure food security and promote sustainable agricultural production in the face of a changing climate. Ultimately, the sustainable management of agricultural water resources is not only essential for ensuring food security but also for protecting ecosystems, supporting rural livelihoods, and promoting economic development. As the global community continues to grapple with the impacts of climate change, it is imperative that we prioritize the development and implementation of sustainable water management practices to safeguard this vital resource for future generations.