Agricultural Water Stress Research Articles

Circular Regenerative Agricultural Practices in Africa: Techniques and Their Potential for Soil Restoration and Sustainable Food Production

The conventional linear system of global food production and consumption is unsustainable as it is responsible for a substantial share of greenhouse gas emissions, biodiversity declines due land use change, agricultural water stress due resource-intensive water consumption patterns and land degradation. During the last decade (1994–2014), for example, the greenhouse emissions from agriculture in Africa were reported to increase at an average annual rate of between 2.9% and 3.1%, equivalent to 0.44 Gt and 0.54 Gt CO2 per annum, respectively. Between 2000 and 2020, the greenhouse gas emissions from agrifood systems were shown to decrease in all major regions of the world, except in Africa and Asia, where they grew by 35 and 20 percent, respectively. With most of the circular agricultural practices still central to food production in the developing African countries, the continent can spearhead a global return to circular agriculture. Using a descriptive review approach, we explore the literature to examine the extent to which African agriculture is deploying these practices, the potential areas for improvement and lessons for the world in embracing sustainable food production. We underscore that the farming communities in sub-Saharan Africa have, for decades, been using some of the most effective circular agricultural principles and practices in agricultural production. We further show that practices and strategies akin to sustainable agricultural production include agronomic practices, smart irrigation options, renewable energy harvesting and waste-to-fertilizer technologies. All of these technologies, which are central to sustainable agricultural production, are not new to Africa, although they may require packaging and advocacy to reach a wider community in sub-Saharan Africa.

What explains rice exports? An analysis of major rice‐exporting countries

AbstractThis study examines the drivers of rice trade. The analysis uses the standard comparative advantage model, the Heckscher–Ohlin–Vanek (HOV) framework, supplemented with a gravity‐type equation. Using the Poisson pseudo‐maximum likelihood (PPML) estimation for data from 2002 to 2020, the analysis broadly confirms HOV model predictions. Results indicate that arable land, along with GDP, distance, precipitation and crop season temperature, significantly influences rice trade dynamics. The results showed that the precipitation play a key role in influencing the rice trade rather than the blue water availability. However, agricultural water stress discouraged exports and encouraged imports.

Water-suitable reclamation can mitigate the amplified agricultural water stress driven by climate change in arid inland basin

The escalation of water scarcity poses a significant challenge to the sustainability of irrigated agriculture in arid regions, with climate change further amplifying the unpredictability of water resources for agricultural purposes. Despite the critical nature of this issue, there is a lack of research identifying effective adaptation strategies and establishing water-suitable thresholds for agricultural development. This study modified a conventional approach for estimating irrigation water use (IWU) in the Heihe agricultural area of Northwest China, integrating the distributed hydrological components of the Soil and Water Assessment Tool (SWAT) model. It modeled IWU and surface water availability across three representative concentration pathways (RCPs) and conducted an extensive analysis of agricultural water scarcity for the period 2021–2050. The study established threshold levels for water-suitable agricultural development based on predicted local water resource conditions. Findings suggested a trend towards warmer and wetter conditions in the Heihe agricultural area over the next three decades. The anticipated average IWU, predicted by five general circulation models (GCMs), was expected to reach 26.785 × 108 m3 (RCP2.6), 26.827 × 108 m3 (RCP4.5), and 26.865 × 108 m3 (RCP8.5). These projections indicated an increase of 0.815 × 108 m3, 0.857 × 108 m3, and 0.895 × 108 m3, respectively, in comparison to the historical period spanning from 1985 to 2014. Streamflow was anticipated to diminish by 0.28 × 108 m3 (RCP2.6), 0.46 × 108 m3 (RCP4.5), and 0.23 × 108 m3 (RCP8.5). The predicted agricultural water scarcity index (WSI) was 1.764 (RCP2.6), 1.789 (RCP4.5), and 1.763 (RCP8.5), indicating a worsening of agricultural water use shortages due to climate change. The study identified controlling the scale of cultivation as the most effective adaptation strategy, recommending that water-suitable agricultural reclamation in the Heihe agricultural area be confined to 25 × 104 ha. This research offers a comprehensive assessment of future water security in an arid inland basin, providing valuable insights into the sustainable development of global irrigated agriculture and adaptation strategies in response to climate change.

Improve food, water, and economic benefits in China’s oases through crop switching

China’s oases are the center of human life and economic development for tens of millions of inhabitants in drylands. However, oases have experienced a significant expansion of cropland during the past three decades, which has resulted in rapidly increasing agricultural water demand and increasing water shortages in the region. Although crop switching is recognized as a promising strategy for improving the sustainability of agricultural production, little is known about how much it can improve the sustainability of oasis cropping systems and whether there are trade-offs among multiple sustainability goals. Here, we used a crop-water-use model, data on crop production and nutrient content, observational data on streamflow, and oasis land-use data to assess the impacts of different crop switching scenarios on water demand, nutrient supply, and income. The results showed that oasis agricultural water demand increased from 28.5 km3 to 41.1 km3 between 1987 and 2017, with 74.6 % of the oasis counties experiencing increasing agricultural water stress. By replacing all crops with those having the lowest water demand in each respective county, the demand for irrigation can be reduced by 23.1 %, and the demand for groundwater reduced by as much as 72.8 %. Crop switching scenarios that also consider crop species diversity, in which replacing the highest water demand crops with alternative crops (those with the lowest water demands, highest protein production, or highest calorie production) in each county can effectively reduce irrigation water demand (8.5–12.9 % for streamflow and 32.7–43.3 % for groundwater), while increasing protein (21.3–35.8 %) and calorie (27.5–42.7 %) production as well as income (1.4–2.4 %). Our research provides potential solutions to effectively alleviate the conflict between agricultural development and the environment in oasis regions.

Overview of Ecological Dynamics in Morocco – Biodiversity, Water Scarcity, Climate Change, Anthropogenic Pressures, and Energy Resources – Navigating Towards Ecosolutions and Sustainable Development

In the context of Morocco’s rich biodiversity and pressing environmental challenges, this paper delves into the intricate dynamics of sustainable development in the country. With a focus on biodiversity conservation, water scarcity, climate change impacts, anthropogenic pressures, and energy resource management, Morocco is navigating ecosolutions and sustainable development. This research highlights the critical importance of biodiversity conservation efforts in preserving the nation’s diverse ecosystems while contributing to national development. Challenges such as forest reduction, agricultural water stress, and declining mammal diversity underscore the urgency of conservation actions. Climate change exacerbates issues in oases, impacting agricultural yields and ecosystem health. This paper also addresses the management of mineral resources and waste production, which pose significant challenges to environmental sustainability. Through strategic policies, international engagements, and capacity-building initiatives, Morocco is striving to achieve resilience and sustainability in the face of evolving global dynamics. By integrating governance, environmental diplomacy, and multilateral cooperation, Morocco is laying a robust foundation for economic growth, social progress, and environmental protection. This manuscript provides a comprehensive overview of Morocco’s environmental challenges, innovative solutions, and commitment to sustainable development in a rapidly changing world.

Modeling the water security in a watershed using the water footprint concept and water scarcity indicators

Abstract Water scarcity has received global attention in the last decade as it challenges food security in arid and semi-arid regions. This study employs water scarcity indices to assess water resources in the agricultural sector of Iran's Jazmourian watershed. Overall, we find that the watershed is experiencing a “very high stress” water situation. This is primarily due to intensive water usage for diverse crops, which has resulted in a negative net virtual water balance and contributed to a rise in water stress and poverty levels. The water stress index is 0.88, and the agricultural water stress is 1.25. The agricultural water footprint is 2,018.53 million cubic meters (MCM), with the share of blue, green and gray water footprints being 80.21, 6.08, and 13.72%, respectively. The region possesses 3,210 MCM of available water for crops, with 17.1% sourced from green waters and 82.9% from blue waters. Despite low annual rainfall and limited water resources, the region excessively exploits water for diverse crops. The net virtual water balance is negative, indicating high virtual water export (1,112–1,605 MCM) compared to imports (58–265 MCM). With declining water availability and increasing crop production, the region experiences rising water stress. The spatial analysis of sub-watersheds reveals diverse patterns of water stress and poverty, as detailed in the study.

One decade (2011–2020) of European agricultural water stress monitoring by MSG-SEVIRI: workflow implementation on the Virtual Earth Laboratory (VLab) platform

ABSTRACT Cloud computing facilities can provide crucial computing support for processing the time series of satellite data and exploiting their spatio-temporal information content. However, dedicated efforts are still required to develop workflows, executable on cloud-based platforms, for ingesting the satellite data, performing the targeted processes, and generating the desired products. In this study, an operational workflow is proposed, based on monthly Evaporative Stress Index (ESI) anomaly, and implemented in cloud-based online Virtual Earth Laboratory (VLab) platform, as a demonstration, to monitor European agricultural water stress. To this end, daily time-series of actual and reference evapotranspiration (ETa and ET0), from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) sensor, were used to execute the proposed workflow successfully on VLab. The execution of the workflow resulted in obtaining one decade (2011–2020) of European monthly agricultural water stress maps at 0.04˚ spatial resolution and corresponding stress reports for each country. To support open science, all the workflow outputs are stored in GeoServer, documented in GeoNetwork, and made available through MapStore. This enables creating a dashboard for better visualization of the results for end-users. The results from this study demonstrate the capability of VLab platform for water stress detection from time series of SEVIRI-ET data.

Evaluation of cooperative and non-cooperative game theoretic approaches for water allocation of transboundary rivers

Efficient water allocation in a transboundary river basin is a complex issue in water resources management. This work develops a framework for the allocation of transboundary river water between the countries located in the river basin to evaluate the characteristics of allocation approaches. The allocation of river water is obtained based on initial-water conditions, cooperative, and non-cooperative game-theoretic approaches. The initial-conditions water allocation approach assigns 34, 40, and 26% of the Harirud River flow to Afghanistan, Iran, and Turkmenistan, respectively. The game-theoretic cooperative approach assigns 36, 42, and 22% of the river flow to Afghanistan, Iran, and Turkmenistan, respectively. The non-cooperative game-theoretic approach establishes that the most stable water allocation was 42, 38, and 20% of the Harirud River flow for Afghanistan, Iran, and Turkmenistan, respectively. Human and agricultural water-stress criteria are used to evaluate the water allocations in the Harirud River basin. The criterion of human water stress has the largest influence in Iran, and the criterion of agricultural water stress has the smallest influence in Afghanistan. This work’s results indicate the initial-conditions water allocation approach favors Turkmenistan, whereas the cooperative and the non-cooperative game-theoretic approaches favors Iran and Afghanistan, respectively. The results show that the priorities of each country governs water allocation, and cooperation is shown to be necessary to achieve sustainable development.

Projection of Agricultural Water Stress for Climate Change Scenarios: A Regional Case Study of Iraq

Assessment of possible changes in crops water stress due to climate alteration is essential for agricultural planning, particularly in arid regions where water supply is the major challenge for agricultural development. This study aims to project climatic water availability (CWA) and crop water demand (CWD) to outline the possible future agricultural water stress of Iraq for different radiative concentration pathways (RCPs). The ensemble means of downscaled precipitation and temperature projections of the selected global climate models (GCMs) were used in a simple water balance model for this purpose. The modified Mann–Kendall (mMK) trend test was employed to estimate the tendency in CWA and the Wilcoxon rank test to evaluate CWD alteration in three future time horizons compared to the base period (1971–2000). The results revealed a decrease in CWA at a rate of up to −34/year during 2010–2099 for RCP8.5. The largest declination would be in summer (−29/year) and an insignificant decrease in winter (−1.3/year). The study also showed an increase in CWD of all major crops for all scenarios. The highest increase in CWD would be for summer crops, approximately 320 mm, and the lowest for winter crops, nearly 32 mm for RCP8.5 in the far future (2070–2099). The decrease in CWA and increase in CWD would cause a sharp rise in crop water stress in Iraq. This study indicates that the increase in temperature is the main reason for a large increase in CWD and increased agricultural water stress in Iraq.

Historical trends in crop water demand over semiarid region of Syria

Climate change has caused a shift in aridity, particularly in the world’s dry regions, affecting several sectors, predominantly the agricultural and water resources. This research examined the climate change effects on crop water demand (CWD) in Syria during 1951–2010. Given the lack of observed data, this analysis relied on Global Precipitation Climatology Center (GPCC) precipitation and Climatic Research Unit (CRU) temperature. Potential evapotranspiration (PET) at each grid was estimated using the Penman–Monteith model and the CWD using the FAO-56 method. The analysis revealed that CWD in Syria increased during 1981 − 2010 compared to that during 1951 − 1980. The increase in CWD was found for grapes, tobacco, barley, and cotton, whereas the maximum changes were during April and May. The most remarkable changes in CWD were for barley, between − 20 and 40 mm. It showed a decreased CWD in the south and a rise in the north (0 − 40 mm). The CWD for wheat showed a decline in most parts of the country, except in the north. The increase in CWD for barley and wheat caused an increase in agricultural water stress in the region. Agriculture planning needs to be developed according to the expected future climate changes to maintain the agricultural production in the region.

Climate change and industrialization as the main drivers of Spanish agriculture water stress

In recent decades, there has been growing concern regarding worsening global climate conditions for agricultural production, especially in Mediterranean climate and other semi-arid areas where the scarcity of water is a major problem. The objective of the study was to estimate the long-term evolution (in Spain, over 1922–2016) of the decoupling between crop's water requirements and the green water available, and to analyze the causes of the changes. The FA0–56 methodology was followed to estimate the green water, blue water and water stress of crops, via an explicit territorial distribution, using 0.5o grid cells. We propose a new indicator called Violet Water. This indicator groups together the water stress of the rainfed croplands and the blue water of the irrigated croplands, representing the components of this decoupling. Our results show that crops´ water requirements increased by 21% and violet water by 30% over the study period. The decomposition analysis used to study the drivers of these changes suggests that increasing reference evapotranspiration, caused by global warming, was the major driver triggering the growth of crop water requirements. Meanwhile, the changes in violet water values were mainly driven by the coupling of the cropland's spatiotemporal structure and climate change. The sensitivity analysis performed showed that the increasing trends in water stress, blue water and violet water were consistent for almost all the tested scenarios, but significant differences on the scale aroused depending on the climate data used (climate normal or each year climate) and specially on the geographical and historical Kc adjustment (crop-fixed Kc versus adjusted Kc). This highlights the importance of considering simultaneously the effect of the different factors, but also the need for refining this type of adjustment in future research.

Assessment of climate change impact on the water footprint in rice production: Historical simulation and future projections at two representative rice cropping sites of China

As one of the most important crops cultivated in China, rice contributes to approximately 28% of total yield. In despite of the substantial production, rice productivity is gravely affected by ongoing climate change and reduction of available water resources. Thus, assessing the responses of rice water consumption and productivity to more pronounced climate change is of great significance to water resources management in terms of relieving the resources shortage and meeting the food demand. In this study, the yield and water resources utilization during 1961–2010 in two typical rice plantation regions of China were evaluated using validated rice model ORYZA2000. Subsequently, their responses to future climate scenarios of 21 century were investigated through driving ORYZA2000 with downscaling climatic projections from GCMs under four RCPs emission scenarios. To quantify the water resources utilization in rice production from multiple perspectives, the water footprint (WF) and three water productivity indices (WPI, WPU and WPET) were integrated for assessing the regional agricultural water stress in this paper. The results revealed that the annual average linear inclining rates of WF in two stations (Kaifeng and Kunshan) were 3.86 m3/ t and 2.62 m3/ t, respectively. Moreover, compared with the green water footprint (WFg), the blue water footprint (WFb) is projected to significantly increase in future. The water productivity (WP) would decrease in two stations under four RCPs scenarios except that the WPu and WPET of Kunshan under RCP2.6 and RCP4.5 scenario in 2020s, 2050s and 2080s. Hence, this study provides insights into comprehensively understand the influences of climate change on food security and sheds lights on the regional strategy for future water resource management.

State-facilitated bottom up in agricultural water governance and sustainability of solutions to recurring water stress: a case study from smallholders’ perspective in Uzbekistan

Agricultural water stress is a critical problem undermining socioeconomic development and environmental sustainability of water and land resources in many agriculture-based economies. Uzbekistan is an example of such case, where for coping with the problem, water reforms such as creation of Water User Associations (WUAs) attempted to decentralize the decision-making to some extent encouraging bottom-up approach to water governance. However, the results have been disappointing so far, particularly visible in persistence of priority in water allocation for farmers with state-ordered crops and neglect of smallholders as legitimate water users. The study presented here describes some of the discrepancies between paper and practice in the example of water governance in one studied community. Using household survey, interviews, and focus group discussion, the authors show that true transformation into bottom up cannot be achieved through pure state-facilitation, especially if it remains on paper and largely limited to technical measures. Such state-facilitated bottom up is bound to fail with the arrival of new levels of water stress. Preferential treatment also undermines incentives of farmers to improve productivity in using water and land resources. The authors highlight that a balanced attention is needed in relation to reforms that encourage not only supply-side solutions, even though they are very necessary. Reforms are also necessary directed at enabling smallholders to participate in decision-making in dealing with water stress, and take more active role in communicating their needs, negotiating fair allocation, and coordinating implementation of agreed water plans.

Agricultural Water Use Sustainability Assessment in the Tarim River Basin under Climatic Risks

Proper agricultural water management in arid regions is the key to tackling climatic risks. However, an effective assessment of the current response to climate change in agricultural water use is the precondition for a group adaptation strategy. The paper, taking the Tarim River basin (TRB) as an example, aims to examine the agricultural water use sustainability of water resource increase caused by climatic variability. In order to describe the response result, groundwater change has been estimated based on the Gravity Recovery and Climate Experiment (GRACE) and the Global Land Data Assimilation System (GLDAS)–Noah land surface model (NOAH) data. In order to better understand the relationship between water resource increase and agricultural water consumption, an agricultural water stress index has been established. Agricultural water stress has been in a severe state during the whole period, although it alleviated somewhat in the mid–late period. This paper illustrates that an increase in water supply could not satisfy agricultural production expansion. Thus, seasonal groundwater loss and a regional water shortage occurred. Particularly in 2008 and 2009, the sharp shortage of water supply in the Tarim River basin directly led to a serious groundwater drop by nearly 20 mm from the end of 2009 to early 2010. At the same time, a regional water shortage led to water scarcity for the whole basin, because the water consumption, which was mainly distributed around Source Rivers, resulted in break-off discharge in the mainstream. Therefore, current agricultural development in the Tarim River basin is unsustainable in the context of water supply under climatic risks. Under the control of irrigation, spatial and temporal water allocation optimization is the key to the sustainable management of the basin.

Assessing water scarcity in agricultural production system based on the generalized water resources and water footprint framework

An indicator, agricultural water stress index (AWSI), was established based blue-green water resources and water footprint framework for regional water scarcity in agricultural production industry evaluation. AWSI is defined as the ratio of the total agricultural water footprint (AWF) to water resources availability (AWR) in a single year. Then, the temporal and spatial patterns of AWSI in China during 1999–2014 were analyzed based on the provincial AWR and AWF quantification. The results show that the annual AWR in China has been maintained at approximately 2540Gm3, of which blue water accounted for >70%. The national annual AWF was approximately 1040Gm3 during the study period and comprised 65.6% green, 12.7% blue and 21.7% grey WFs The space difference in both the AWF for per unit arable land (AWFI) and its composition was significant. National AWSI was calculated as 0.413 and showed an increasing trend in the observed period. This index increased from 0.320 (mid-water stress level) in 2000 to 0.490 (high water stress level) in the present due to the expansion of the agricultural production scale. The Northern provinces, autonomous regions and municipalities (PAMs) have been facing high water stress, particularly the Huang-Huai-Hai Plain, which was at a very high water stress level (AWSI>0.800). Humid South China faces increasingly severe water scarcity, and most of the PAMs in the region have converted from low water stress level (AWSI=0.100–0.200) to mid water stress level (AWSI=0.200–0.400). The AWSI is more appropriate for reflecting the regional water scarcity than the existing water stress index (WSI) or the blue water scarcity (BWS) indicator, particularly for the arid agricultural production regions due to the revealed environmental impacts of agricultural production. China should guarantee the sustainable use of agricultural water resources by reducing its crop water footprint.

Impact of climate change on the water requirement of summer maize in the Huang-Huai-Hai farming region

Crop water requirement and the temporal and spatial changes of this important characteristic provide key information for irrigation scheduling, water resource planning, and future decision-making. In the Huang-Huai-Hai (HHH) farming region in north China, both crop evapotranspiration (ETc) and evapotranspiration of the applied water (ETaw) in the growing season of summer maize during 1960–2009 were calculated using the SIMETAW (simulation of evapotranspiration of applied water) model and the daily weather data. Inverse distance weighted interpolation (IDW) was used to interpret spatial distribution of ETc and ETaw. Results showed that: (1) During 1960–2009 in the HHH farming region, ETc of summer maize during the growing season showed a significant downward trend; the average ETc decreased from 335.6mm/decade in the period 1960–1969 to 311.4mm/decade in the period 2000–2009. The variation of ETaw of summer maize during the growing season did not drop significantly due to yearly fluctuation of the effective rainfall (Re) in the growing season, and the improvement of irrigation efficiency and cultivation management measures. Although the descent of ETc might mitigate the agricultural water stress in this area to some extent, the variation of ETaw still depended on the effective rainfall. (2) The average ETc values per decade presented higher in the eastern and lower in the western regions; inter-regional differences were observed for ETaw, and the highest ETaw value of about 109.6mm was found in the western regions of the Shandong and Hebei Provinces. Adjusting irrigation system and adopting the different irrigation systems in different region should be taken into consideration to guarantee the maize yield in this area. (3) During 1960–2009, a significant overall increase in temperature, a significant decrease in wind speed, humidity, and solar radiation, and a slight decrease in precipitation were observed. The solar radiation decrease contributed most to the summer maize ETc decrease, while relative humidity and precipitation were negatively correlated with ETc.

An empirical framework for scaling-out of water system innovations: Lessons from diffusion of water system innovations in the Makanya catchment in Northern Tanzania

Abstract Scaling-out of water system innovations such as soil and water conservation is important for increased and sustainable agricultural production. A wealth of upgraded soil and water conservation technologies such as terraces has not been widely adopted in places vulnerable to land degradation and agricultural water stress. Much focus should be on rethinking approaches for scaling-out of well-proved innovations rather than on generation of new technologies. This paper presents an empirical framework for scaling-out water system innovations at catchment level. The framework is built based on findings from studies that were conducted in the Makanya catchment in Northern Tanzania. The empirical data and information were collected through inter-related research methods entailing farmers’ questionnaire surveys and consultations with key NGOs involved in the promotion of agricultural land and water management technologies. The data collection involved 234 and 294 farmers in the first and second rounds, respectively. The framework has four stages, which are technology and community strength evaluation, partnership building, scaling-out process and uptake evaluation. Stage 1 evaluates the technology efficacy in conserving soil and water and increasing benefits, and community strength mainly in terms of social capital. Stage 2 entails partnering with the target community and change agents to champion the scaling-out process in the target community. Stage 3 is concerned with the actual innovation scaling-out process through effective pathways such as field demonstration, lead farmers and appropriate channels of communication. Stage 4 evaluates the outcome of the innovation scaling-out process. Though the framework is developed using field evidences related to scaling-out of terraces, it could be adapted to enhance scaling-out of other water system innovations.

Evaluation of the OhmMapper Instrument for Soil Moisture Measurement

An instrument for making rapid measurements of the soil moisture content in the root zone is an essential tool for many applications, including understanding of soil water dynamics, evaluation of agriculture water stress, and validation of soil moisture modeling. Studies have shown that electrical resistance measurements may be used to infer soil moisture content under special circumstances. In this paper, electrical resistivity (resistance multiplied by a geometric factor) measurements of the soil by the Geometrics Inc. OhmMapper instrument are compared with point measurements of soil moisture to a depth of 70 cm. It was found that the OhmMapper resistivity measurements could be used to infer soil moisture content with a coefficient of determination as high as 0.34 when a simple power law relationship was used. A more sophisticated analysis of the resistivity measurements could potentially lead to a greater coefficient of determination.