Water Footprint Of Crop Production Research Articles

Water Footprint Assessment of Agricultural Production in Bilecik Province

The freshwater sources are under serious pressure both in terms of quality characteristics due to pollution and in terms of quantity due to the increase in parameters such as temperature and evaporation under the influence of global warming. To ensure sustainable use of these resources, it is necessary to employ high-efficiency pressurized irrigation systems and cultivate plant species that are resilient to various stress factors and highly productive. In determining the water usage characteristics of plants, rapid atmospheric effects brought by climate change, plant water and temperature stress, soil moisture should be monitored, and water production indicators should be determined. In the water-intensive agricultural sector, monitoring the water footprint has become one of the important indicators in terms of ensuring water-food-energy sustainability, efficient use and fair sharing of water resources. This study aims to determine the water footprint of agricultural production in Bilecik province and its districts located in the transitional zone. Accordingly, values of crop and livestock production throughout the province and using a volume-based approach, the water footprint of crop production is estimated at 0.6 billion cubic meters (BCM), while the water footprint of livestock production is 0.5 BCM, resulting in a total agricultural water footprint of 1.1 BCM. In crop production, green water footprint constitutes 33%, blue water footprint 59%, and grey water footprint 8% of the total water footprint. The data obtained will form the basis for developing strategies in sustainable water and food management, aligned with climate change scenarios, to achieve sectoral supply-demand balance.

Driving factor analysis of spatial and temporal variations in the gray water footprint of crop production via multiple methods: A case for west China

The gray water footprint (GWF) can quantitatively evaluate the effect of non-point pollution on water quality in the context of water quantity. It is crucial to explore the driving forces behind the GWF to solve water quality problems. This study quantified the unit GWFs of grain crops and oil crops at the municipal scale in six provinces of western China over 2001–2018, then jointly applied the extended STIRPAT model and path analysis methods to analyze the climatic and socioeconomic driving forces of the GWF. Results show that the key driving forces affecting the GWF obtained by the two methods were consistent. Planting structure and population were the main factors increasing the total GWF, while crop yield was the largest factor inhibiting the unit GWF and demonstrates regional differences. However, when the indirect influence of the driving factor through other factors was large, some driving forces obtained by different methods were reversed. For example, the indirect impact of per capita cultivated land area on the total GWF in Inner Mongolia was large, resulting in a significant positive impact in path analysis and a slight negative impact in the STIRPAT model. To draw more comprehensive and referential conclusions, we suggest using multiple methods together to verify the driving forces and account for the regional differences.

Water Resources Evaluation in Arid Areas Based on Agricultural Water Footprint—A Case Study on the Edge of the Taklimakan Desert

Water scarcity is an important factor limiting agricultural development in arid areas. Clarifying and evaluating the current situation of water resources in arid regions is helpful for decision-makers in the rational use of water resources. This study takes a typical arid region located at the edge of Taklamakan Desert-Hotan region as the study area. The water footprint (WF) of the Hotan region was calculated based on 20 years of data information from 2000–2019. An evaluation system was established using four aspects of the WF: structural indicators, efficiency indicators, ecological safety indicators, and sustainability indicators. The results show that the WF of the study area is mainly dominated by blue water consumption, with a proportion of 65.74%. The WF of crop production is larger than that of livestock production. The produced WF of grain crops is the highest of all products with a share of 44.21%. The increase in the local agricultural WF reached 53.18% from 2000 to 2019, but it was still lower than the amount of water available for agriculture. The evaluation results indicated that the region’s WF import dependency is lower than the global level, with an annual average self-sufficiency rate of 91.13% and an increase of 878.95% in the WF economic efficiency index. The agricultural WF produced in Hotan is exported in the form of trade, but the quantitative contribution is small and does little to relieve water stress in other regions. The agricultural water consumption was still within the range of local water resources that could be carried but only 6 years of sustainable water use, and the future development was not optimistic. With the ratio of produced WF to available water resources maintained at about 58%, the local available water resources should be above 43.21 × 108 m3 to initially ensure the sustainable use of water resources. There were 12 drought years in the study period, which are prone to droughts and high disaster levels. The drought-water scarcity systems behaved in three phases: 2000–2011 (uncoordinated level), 2012–2015 (transitional phase), and 2016–2019 (coordinated level). Water scarcity threatened by drought reduced. The occurrence of meteorological droughts was more related to natural factors while the changes in WF were mainly driven by socio-economic elements such as human activities.

Assessment of water footprint for a few major crops in Banas River Basin of Rajasthan

Water security is essential for socio-economic development, ecosystem management, and environmental sustainability. An improved understanding of the relationships between water demand and supply is needed to mitigate the impacts of diminishing water resources. The present study aimed to assess the crop water footprint of sixteen major crops in the basin namely, bajra/ pearl millet (Pennisetum glaucum L.), barley (Hordeum vulgare L.), cotton (Gossypium herbaceum L.), gram/chickpea (Cicer arietinum L.), groundnut (Arachis hypogaea L.), guar/cluster beans (Cyamopsis tetragonoloba L.), jowar/ sorghum (Sorghum bicolor L.), lentil/ masoor (Lens culinaris L.), maize (Zea mays L.), mungbean (Vigna radiata L.), rapeseed & mustard (Brassica napus L.), rice/paddy (Oryza sativa L.), sesame (Sesamum indicum L.), soybean (Glycine max L.), urad/ black gram (Vigna mungo L.) and wheat (Triticum aestivum L.) was estimated during 2008-2020 in the Banas river basin of Rajasthan. The average annual water footprint of crop production varied from 11365.8-23131.5 MCM/yr (Mean 19254.5 MCM/yr) during the study period. Wheat, bajra, maize, rapeseed & mustard make up 67.4 % of the total average annual water footprint of crop production. The blue water footprint of crop production was 3942.1 MCM/yr, with wheat, rapeseed & mustard accounting for almost 87.0 % of the average annual blue water footprint. Blue, green and grey water footprints comprised 20.8, 69.7 and 9.5 % of the total WF of crop production in the basin, respectively. This assessment can play a significant role in developing better policies for properly managing water footprints for sustainable crop production in the basin.

Spatial-temporal variations in green, blue and gray water footprints of crops: how do socioeconomic drivers influence?

Nowadays, more than 70% of global freshwater is used for agriculture. The evaluation of the water footprint of crops (CWFs) is an important method to measure the effects of crop production on water resource utilization and water environmental pollution. However, little attention is paid to the impact of socioeconomic development differences on the water footprint of each crop. In this study, the green, blue, and gray water footprints of crop production were quantified, and the socioeconomic drivers of changes in the CWFs were revealed. It is of great significance to provide targeted guidance for agricultural water management in Heilongjiang, a province with the largest crop production in China. Here, we show that the total water footprint of crop production (TWF) increased from 62.2 billion m3 to 101.8 billion m3, and high-value areas were mainly concentrated in the west and south of Heilongjiang Province. Over 95% of the total grain crops sown were covered by maize, rice and soybean, which presented the greatest TWF. The share of green water footprint in TWF has increased, and crop growth is increasingly dependent on rainfall. Furthermore, our results highlight that the effective irrigated quota and crop-planting scale for maize and rice contribute to TWF increase. The TWF and agricultural value-added score were weakly decoupling in most municipalities, indicating the improved efficiency of crop water use; the TWF is growing slower than the economy, which is undesirable. Changes in TWF and agricultural value-added score were the same as the left half of the inverted ‘U of the ‘Environmental Kuznets Curve’, which has not reached the ‘inflection point’. More efforts to control the effective irrigated quota and crop-planting scale while improving effective irrigated efficiency are needed to ensure that economic growth does not come at the expense of consuming enormous quantities of water.

Regional water footprint assessment for a semi-arid basin in India.

Water footprint assessment enables us to pinpoint the impacts and limitations of the current systems. Identifying vulnerabilities across various regions and times helps us prepare for suitable actions for improving water productivity and promoting sustainable water use. This study aims to provide a comprehensive evaluation of the sector-wise water footprint in the Banas River Basin from 2008–2020. The water footprint of the Banas River Basin was estimated as 20.2 billion cubic meters (BCM)/year from all sectors. The water footprint has increased over the year with the increase in population, the number of industries, and crop production demand. The average annual water footprint of crop production varied from 11.4–23.1 BCM/year (mean 19.3 BCM/year) during the study period. Results indicate that the water footprint has nearly doubled in the past decade. Wheat, bajra, maize, and rapeseed & mustard make up 67.4% of crop production’s total average annual water footprint. Suitable measures should be implemented in the basin to improve water productivity and promote sustainable water use in agriculture, which accounts for nearly 95.5% of the total water footprint (WF) of the Banas basin. The outcomes of the study provide a reference point for further research and planning of appropriate actions to combat water scarcity challenges in the Banas basin.

Rising agricultural water scarcity in China is driven by expansion of irrigated cropland in water scarce regions

Rising agricultural water scarcity in China is driven by expansion of irrigated cropland in water scarce regions

Simulation of soil desiccation effects and production water footprint of apple orchards in different precipitation areas of the Loess Plateau, China

To clarify the desiccation effect of deep soil and water footprint of crop production in two typical dry-farming apple orchards on the Loess Plateau of China, with Luochuan County in semi-humid region and Mizhi County in semi-arid region as two typical apple planting areas, we used the WinEPIC model to quantitatively simulate and analyze the variations of soil moisture from 0 to 15 m and water footprint of apple production during 1980-2020. The results showed that annual yield of mature orchards in Luochuan and Mizhi followed an "S" curve, with the average annual values being 24.64 and 18.42 t·hm-2, respectively. The average annual evapotranspirations of Luochuan and Mizhi were 623.82 and 458.97 mm, the average annual drought stress days of Luochuan and Mizhi were 20.4 and 52.73 days, and the water overconsumption were 167.94 and 121.15 mm, respectively. The available soil water contents in Luochuan and Mizhi showed a sharp decline from 1 to 25 years old and from 1 to 23 years old, respectively, with average annual soil desiccation rates being 64.6 and 68.03 mm·a-1, respectively. The dry layer of deep soil for the orchards of Luochuan and Mizhi appeared at the 13th and 7th years, and would be stable after 23 and 22 years, respectively. The formation and stability time of the soil dry layer in the area with high precipita-tion was later than that with low precipitation. Long-term soil moisture deficit would result in irreversible soil dry layer. Water footprint of apple production in Luochuan and Mizhi were low in the early stage and high in the later stage, with the average annual values being 0.187 and 0.194 m3·kg-1, respectively. Both apple yield and production water footprint were affected by precipitation. To ensure the sustainable and healthy development of apple industry, it was recommended that the optimal planting age of apple trees is about 23 years on the Loess Plateau where water sources is limited, and the maximum should not exceed 25 years.

The climate cost of saving water by different plastic mulching patterns

Global water shortage and climate change are two of the most significant challenges for our planet, and how to coordinate their relationship is a problem unsolved. In this study, we proposed the synchronization index of water-saving and CO2 mitigation to evaluate the climate cost of saving water by different plastic mulching patterns and explore way to improve the synchronization. The water-saving performance, carbon footprint, and the synchronization index were analyzed for three typical plastic mulching patterns, namely conventional partial plastic mulching, full plastic mulching, and “one film for two years” mulching. The results indicated that all three types of plastic mulching systems were effective in reducing the water footprint of crop production, with full plastic mulching showing the best performance in terms of improving crop yields and water savings. The application of plastic mulching mainly influences the carbon footprint through increasing indirect greenhouse gas emission, accelerating soil organic carbon decline and increasing N2O emission. Area-scale carbon footprint showed a significant positive relationship with the input amounts of plastic film, and the sort order of yield-scale carbon footprint was partial plastic mulching > full plastic mulching > “one film for two years” mulching. Calculated synchronization index was -0.35 kg CO2-eq m−3, -0.10 kg CO2-eq m−3, and 0.50 kg CO2-eq m−3 for partial plastic mulching, full plastic mulching, and “one film for two years” mulching, respectively. Full plastic mulching and partial plastic mulching resulted in an additional 0.35 and 0.10 kg of CO2-eq for saving one cubic meter of water, and only “one film for two years” mulching resulted in simultaneous water savings and greenhouse gas mitigation. This study suggests that water savings achieved using conventional partial plastic mulching have costs in terms of climate change. Faced with the dual pressure of global water shortages and climate change, controlling input amounts of plastic film and prolonging the lifetime of the film are simple and effective way to coordinate water savings and greenhouse gas mitigation. Moreover, the results of this study suggested that water savings and GHG emission mitigation cannot necessarily be achieved simultaneously and that searching for both water-saving performance and its synchronization with GHG mitigation should become a new paradigm for the development of water-saving technologies in the future.

Crop Water-Saving Potential Based on the Stochastic Distance Function: The Case of Liaoning Province of China

Scientific evaluation of crop water use efficiency is of great significance for ascertaining water-saving potential and realizing efficient utilization of water resources. In this paper, we calculated the water footprint of crop growth, pollution water footprint and production water footprint of 14 cities in Liaoning Province, China, by using the water footprint theory, established the crop water use efficiency model of stochastic frontier distance function, and analyzed the spatial-temporal variation characteristics of crop water use efficiency (WUE), ecological WUE and production WUE. Results show that: (1) the average water footprint of crop growth was 1.714 × 109 m3, the ecological water footprint of crop was 6.26 × 108 m3, and the water footprint of crop production was 2.34 × 109 m3 from 2001 to 2017 for the whole province. (2) the WUE of crop growth was 0.821, the crop ecological WUE was 0.845 and crop production was 0.865, respectively. We concluded that Liaoning province can save 17.9% of crop consumption water, equivalent to 8.38 × 108 m3, 15.5% of ecological water, equivalent to 7.25 × 108 m3 and 13.5% of production water, equivalent to 6.32 × 108 m3 by strengthening the popularization of agricultural high-efficiency water use technology and improving the level of policy management. This research provides a basic support for the evaluation of crop water-saving potential with the stochastic frontier approach in other regions.

A Decoupling Analysis of the Crop Water Footprint Versus Economic Growth in Beijing, China

Beijing, the capital of China, is experiencing a serious lack of water, which is becoming a main factor in the restriction of the development of the social economy. Due to the low economic efficiency and high consumption proportion of agricultural water use, the relationship between economic growth and agricultural water use is worth investigating. The “decoupling” index is becoming increasingly popular for identifying the degree of non-synchronous variation between resource consumption and economic growth. However, few studies address the decoupling between the crop water consumption and agricultural economic growth. This paper involves the water footprint (WF) to assess the water consumption in the crop production process. After an evaluation of the crop WF in Beijing, this paper applies the decoupling indicators to examine the occurrence of non-synchronous variation between the agricultural gross domestic product (GDP) and crop WF in Beijing from 1981 to 2013. The results show that the WF of crop production in 2013 reduced by 62.1% compared to that in 1980 — in total, 1.81 × 109 m3. According to the decoupling states, the entire study period is divided into three periods. From 1981 to 2013, the decoupling states represented seventy-five percent of the years from 1981 to 1992 (Period I) with a moderate decoupling degree, more than ninety percent from 1993 to 2003 (Period II) with a very strong decoupling degree and moved from non-decoupling to strong decoupling from 2004 to 2013 (Period III). Adjusting plantation structure, technology innovation and raising awareness of water-saving, may promote the decoupling degree between WF and agricultural GDP in Beijing.

Quantitative evaluation of spatial scale effects on regional water footprint in crop production

The water footprint of crop production (WFP) is among the most comprehensive agricultural water-consumption evaluation tools because it describes the amount, type, and location of water consumed. However, existing literatures on WFP quantification and evaluation are only aimed at a specific spatial level, and currently, there is a lack of quantitative research on the effects of different spatial levels on the variation in WFP. Herein, we calculated the spatial distribution of wheat WFPs in China from 2000 to 2014 at five different spatial levels: crop field, county, river sub-basin, provincial, and large river basin. In addition, we analysed and compared the key driving forces of wheat WFP at these spatial levels, focusing on meteorological and human management factors. Each spatial level had distinct spatial distributions. Human management factors demonstrated more significant effects on the WFP of large river basins, but the meteorological factors were the key drivers at smaller spatial levels. In conclusion, our study quantitatively revealed a non-negligible effect of spatial scale on WFP. Thus, for large river basins, agricultural water resource managers at each spatial level must clarify their different priorities across spatial levels while formulating water-saving and regulation measures.

Crop Production Allocations for Saving Water and Improving Calorie Supply in China

The limited available water resources and competition among different water use sectors have become the main constraints of food security and sustainability. Faced with the inability to expand the area of cultivated land due to urbanization and population growth, one of the biggest challenges and risks for developing countries is to ensure the supply of food quantity and quality under extremely limited water resources. To achieve water-saving and improve calorie supply by adjusting crop production allocations, three objectives—of minimum blue water footprint, maximum calorie production, and each crop production no less than the reference level of nine main crops in China—were achieved using a non-dominated sorting genetic algorithm II. The results display that compared with the reference year, model Maize+ (maize production increased) had significant blue water saving (~32%), the blue water footprint of crop production in all provinces reduced, and its calorie production increased by 4%. This solution is not realistic for China because wheat and rice production need to be reduced by 82 and 80%, respectively. However, model Citrus– (citrus production decreased) reduced the blue water footprint of crop production (~16%), and increased calorie production (~12%). Compared with other solutions, it is a sustainable crop production structure that is easier to realize because it is better at meeting the production of each crop. Therefore, China can appropriately increase the planting area of maize and reduce the planting of citrus and other crops that consume more blue water and produce fewer calories to ensure the security and sustainability of food supplies. However, the improvement of water saving-technology, rationalization of agricultural water resources management, crop production allocations mentioned in this study, and other efforts are necessary to achieve this goal.

The Water Footprint of Global Food Production

Agricultural production is the main consumer of water. Future population growth, income growth, and dietary shifts are expected to increase demand for water. The paper presents a brief review of the water footprint of crop production and the sustainability of the blue water footprint. The estimated global consumptive (green plus blue) water footprint ranges from 5938 to 8508 km3/year. The water footprint is projected to increase by as much as 22% due to climate change and land use change by 2090. Approximately 57% of the global blue water footprint is shown to violate the environmental flow requirements. This calls for action to improve the sustainability of water and protect ecosystems that depend on it. Some of the measures include increasing water productivity, setting benchmarks, setting caps on the water footprint per river basin, shifting the diets to food items with low water requirements, and reducing food waste.

Impacts of Climatic and Agricultural Input Factors on the Water Footprint of Crop Production in Jilin Province, China

Water consumption ensures crop production and grain security, and is influenced by many factors. Analyzing the impact factors of water consumption during crop production will be beneficial to the full use of water resources and crop growth. Jilin Province is one of the major crop production areas in China and is facing water shortages. Using the water footprint as an indicator, this study evaluated the water consumption of crop production in Jilin Province during 2000–2016, explored the impacts of climatic and agricultural input factors on the water consumption of crop production, and identified the most influential factors in years under different levels of rainfall. The results indicate that the crop water footprint exhibited a decreasing trend during 2000–2016, and the most influential factors of the crop water footprint changed over the years with different levels of rainfall. Precipitation and the effective irrigation area were the most influential factors in the drought year, and accumulated temperature, machinery power, and chemical fertilizer consumption were the most influential factors in normal and humid years. The most influential factors of the crop water footprint differed in different regions with the differences in natural and human interfered conditions. Identifying the impacts of the most influential factors on the water consumption of crop production would be conducive to optimizing farmland management and achieving sustainable agricultural production.

Evaluating agricultural water-use efficiency based on water footprint of crop values: a case study in Xinjiang of China

Efficient agricultural water use is crucial for food safety and water conservation on a global scale. To quantitatively investigate the agricultural water-use efficiency in regions exhibiting the complex agricultural structure, this study developed an indicator named water footprint of crop values (WFV) that is based on the water footprint of crop production. Defined as the water volume used to produce a unit price of crop (m3/CNY), the new indicator makes it feasible to directly compare the water footprint of different crops from an economic perspective, so as to comprehensively evaluate the water-use efficiency under the complex planting structure. On the basis of WFV, the study further proposed an indicator of structural water-use coefficient (SWUC), which is represented by the ratio of water-use efficiency for a given planting structure to the water efficiency for a reference crop and can quantitatively describe the impact of planting structure on agricultural water efficiency. Then, a case study was implemented in Xinjiang Uygur Autonomous Region of China. The temporal and spatial variations of WFV were assessed for the planting industries in 14 prefectures and cities of Xinjiang between 1991 and 2015. In addition, contribution rate analysis of WFV for different prefectures and cities was conducted to evaluate the variations of WFV caused by different influencing factors: agricultural input, climatic factors, and planting structure. Results from these analyses indicated first that the average WFV of planting industries in Xinjiang significantly decreased from 0.293 m3/CNY in 1991 to 0.153 m3/CNY in 2015, corresponding to an average annual change rate of −3.532%. WFV in 13 prefectures and cities (with the exception of Karamay) has declined significantly during the period of 1991–2015, indicating that agricultural water-use efficient has effectively improved. Second, the average SWUC in Xinjiang decreased from 1.17 to 1.08 m3/CNY in the 1990s, and then declined to 1.00 m3/CNY in 2011–2015. The value of SWUC was highly consistent with the relative value of WFV in most prefectures and cities, showing that planting structure is one of the primary factors affecting regional agricultural water-use efficiency. Third, the contribution rate of WFV variations from human factors including agricultural input and planting structure was much more significant than that from climatic factors. However, the distribution of agricultural input and the adjustment of planting structure significantly differed among prefectures and cities, suggesting regional imbalances of agricultural development. This study indicated the feasibility and effectiveness of controlling agricultural water use through increasing technical input and rational selection of crops in the face of impending climate change. Specifically, we concluded that, the rational application of chemical fertilizers, the development of the fruit industry, and the strict restriction of the cotton industry should be implemented to improve the agricultural water-use efficiency in Xinjiang.

Changing global cropping patterns to minimize national blue water scarcity

Abstract. Feeding a growing population with global natural-resource constraints becomes an increasingly challenging task. Changing spatial cropping patterns could contribute to sustaining crop production and mitigating water scarcity. Previous studies on water saving through international food trade focussed either on comparing water productivities among food-trading countries or on analysing food trade in relation to national water endowments. Here, we consider, for the first time, how both differences in national average water productivities and water endowments can be considered to analyse comparative advantages of countries for different types of crop production. A linear-optimization algorithm is used to find modifications in global cropping patterns that reduce national blue water scarcity in the world's most severely water-scarce countries, while keeping global production of each crop unchanged and preventing any increase in total irrigated or rainfed harvested areas in each country. The results are used to assess national comparative advantages and disadvantages for different crops. Even when allowing a maximum expansion of the irrigated or rainfed harvested area per crop per country of only 10 %, the blue water scarcity in the world's most water-scarce countries can be greatly reduced. In this case, we could achieve a reduction of the global blue water footprint of crop production of 21 % and a decrease of the global total harvested and irrigated areas of 2 % and 10 % respectively. Shifts in rainfed areas have a dominant share in reducing the blue water footprint of crop production.

Quantifying the Inter- and Intra-Annual Variations in Regional Water Consumption and Scarcity Incorporating Water Quantity and Quality

Water stress due to poor water quality has been becoming severe in many places across the world. Comprehensive water utility and water scarcity assessments require information integrating both water quantity and quality. While massive attentions have been paid to water quantity scarcity evaluations, little effort has been made to assess inter-annual variations of regional water scarcity resulting from both water quantity and quality. The study, taking water-abundant while stressed Jiangsu province (JSP) in eastern China as the study area, investigated (i) the development in green, blue and grey water footprint (WFs) for crop production, over 1986–2016, (ii) the inter-annual evolutions in blue and grey WFs for industry and households over 2010–2016 and (iii) the associated inter- and intra-annual variations in water scarcities resulting from water quantity and quality. Results showed that the annual total WF of crop production in JSP increased by 18% between 1986 and 2016. Grey WF accounted for 77% of the total WF at an annual average level. Crop production occupied 61% and household accounted for 34% in the total grey WF related to N. The monthly blue water scarcity levels in JSP increased by 4 (October 2016) – 62 (February 2012) folders when water quality effects were taken into account. The wetter the year, the lower the blue water scarcity of water quality and quantity. As a sensitive and crucial region with both severe water pollution scarcity and the role of water source region in the huge South-to-North water transfer project, it is of great necessity to enhance the water pollution management and increase information transparency among water authorities and consumers.

The Water Footprint Assessment of Agriculture in Banjar River Watershed

The water footprint (WF) is a spatially explicit character of water use in terms of consumption or pollution for producing a product, commodity or service. The WF of a crop may be defined as the amount of water required for producing the crop over the complete growing season. The present study was carried out to assess the WF of agriculture in Banjar river watershed (BRW) over the period 2000 - 2013. The WF of crops were evaluated and their further multiplication with production (ton/yr) in the watershed yielded the water footprint of crop production (WFCP) in Banjar river watershed whose further summation gave WF of agriculture in BRW. The findings depicted that the water footprint of rice was maximum (7848 m3/ton) followed by gram (5782 m3/ton) and wheat (5417 m3/ton). The crop with least WF was maize (2886 m3/ton). These values of WF are much higher than the national average WF for different crops grown in India. Lower crop yields due to improper irrigation practices, low fertilizer application rates and improper on farm water management practices are the primary reasons of such high values of WF of crops in BRW. The water footprint of agriculture in BRW was 690.37 million m3/yr with 59.74 % WFgreen, 39.69 % WFblue and 0.56 % WF grey. Rice was having maximum share in water footprint of agriculture in BRW with 87.38 % of total water footprint followed by gram (4.97 %), wheat (4.33 %) and maize (1.31%).

Water scarcity alleviation through water footprint reduction in agriculture: The effect of soil mulching and drip irrigation

Water scarcity has received global attention in the last decade as it challenges food security in arid and semi-arid regions, particularly in the Middle East and North Africa. This research assesses the possible alleviation of water scarcity by reducing the water footprint in crop production through the application of soil mulching and drip irrigation. The study is the first to do so at catchment scale, taking into account various crops, multi-cropping, cropping patterns, and spatial differences in climate, soil, and field management factors, using field survey and local data. The AquaCrop-OS model and the global water footprint assessment (WFA) standard were used to assess the green and blue water footprint (WF) of ten major crops in the Upper Litani Basin (ULB) in Lebanon. The blue water saving and blue water scarcity reduction under these two alternative practices were compared to the current situation. The results show that the WF of crop production is more sensitive to climate than soil type. The annual blue WF of summer crops was largest when water availability was lowest. Mulching reduced the blue WF by 3.6% and mulching combined with drip irrigation reduced it by 4.7%. The blue water saving from mulching was estimated about 6.3 million m3/y and from mulching combined with drip irrigation about 8.3 million m3/y. This is substantial but by far not sufficient to reduce the overall blue WF in summer to a sustainable level at catchment scale.