Water Footprint Reduction Research Articles

Coastal Salinity Management and Cropping System Intensification through Conservation Agriculture in the Ganges Delta

Soil salinity is the major constraint for cropping system intensification in the coastal region of the Ganges Delta. Salts build up on the soil surface, as well as in the crop root zone, due to the capillary rise in underground brackish water, hampering the growth and development of crops and resulting in mortality and low yields. We studied, for three years (2020–2021 to 2022–2023), the effect of conservation agricultural practices (zero tillage planting, crop residue recycling, and crop rotations) on the major soil properties (soil salinity and organic carbon status), crop performance (yield and economics), and water footprint. Conservation agricultural practices significantly reduce soil salinity, build soil organic carbon, reduce water footprint, and increase the profitability of cropping systems compared to tillage-intensive conventional practices. Under conventional agriculture, the sole cropping of rice is more profitable than double and triple cropping systems.

The Impact of Sustainability Courses: Are They Effective in Improving Diet Quality and Anthropometric Indices?

There are studies on the effect of general nutrition education on diet quality and anthropometric measurements, while studies showing the effectiveness of sustainable nutrition education, which also addresses the effect of food on the environment, are quite limited. This study aimed to investigate the effects of sustainable nutrition education on diet quality, anthropometric measurements, and the carbon footprint (CFP) and water footprint (WFP) of diet. A total of 160 university students received 1 h of sustainable nutrition education for 6 weeks. Before, at the end of, and 2 months after the courses, 24 h food consumption records were taken to assess diet quality and CFP and WFP values of diet, and Mediterranean diet (MedDiet) and Healthy Eating Index (HEI)-2020 scores were evaluated. The results of the study showed that sustainable nutrition education increased MedDiet score by 1.86 points and HEI-2020 score by 7.38 points. This education program also decreased body weight, body mass index (BMI), fat mass, and neck circumference. Sustainability education has a positive impact on calcium, potassium, and magnesium intakes, a negative impact on vitamin B12 and zinc intakes, and no effect on total protein intake. Education resulted in a 22% reduction in CFP and a 10% reduction in WFP.

Improving Microalgae Feasibility Cultivation: Preliminary Results on Exhausted Medium Reuse Strategy

Although microalgae exploitation is very promising, process sustainability is undermined by biomass production and harvesting. Among the various bottlenecks of the production process, particular attention should be paid to the water footprint. Indeed, a huge volume of water is required in microalgae production. Water reuse can support both the water footprint and medium cost reduction, saving water and unconverted substrates. The present study reports preliminary results regarding the utilization of a water reuse strategy for two Chlorophyta microalgae under batch conditions. Growth parameters and chlorophyll content are monitored and the optimal amount of reused medium is assessed. The results show that 70% of the medium can be reused with no loss of specific growth rate and chlorophyll fraction for Pseudococcomyxa simplex in three consecutive batch cultivations. By contrast, a significant decline in Chlorella vulgaris growth was observed after the first cultivation in reused medium, across all tested conditions.

Enhancing productivity while reducing water footprint and groundwater depletion: Optimizing irrigation strategies in a wheat-soybean planting system

ContextTraditional agricultural practices in the Huang-Huai-Hai Plain have led to a decrease in groundwater level, coupled with frequent extreme rainfall in recent years, has seriously threatened grain production and sustainability. ObjectiveThe objective of this study is to evaluate water footprint, groundwater table, and system productivity through a three-year field experiment that focuses on transitioning from the conventional winter wheat-maize (WM) to winter wheat-soybean (WS) system, while integrating suitable irrigation strategies. MethodsMicro-sprinkling irrigation strategies were applied during the winter wheat season, when the soil water content (SWC) of the 40 cm soil layer dropped to 40% of its field capacity (FC). Specifically, W4 treatment irrigated until SWC reached 60% FC at a depth of 40 cm, while the W6 treatment irrigated to SWC reaching 80% FC at a 60 cm depth. In contrast, a rain-fed (W0) treatment served as the control. Field water consumption was simulated using the Water Heat Carbon Nitrogen Simulator (WHCNS) model. Results and conclusionsThe results revealed that the WS system exhibited less variability in evapotranspiration (ETc) compared to WM system, with reductions ranging from 23.6% to 29.1%. Furthermore, the WS system contributed substantially to elevating the groundwater table by 58.4–146.4% while maintaining a higher and more stable annual wheat equivalent yield (WEY) compared to the WM system. The W4 treatment saved 97.9–98.2 mm of irrigation water compared to the W6 treatment, improved water productivity by 10.7–32.1%, and reduced the water footprint by 14.3–25.1%. SignificanceTransitioning from the traditional WM cropping system to the WS system, and adapting an appropriate irrigation regime (W4) can counterbalance extreme weather impacts on crop yields. This study provides valuable insights into sustainable farming practices, and it may provide a practical framework for striking a balance between groundwater conservation and food security.

Concept and importance of soil moisture potentials in agriculture

The root design of crops in soils has a direct impact on yield potentials, which are controlled by soil moisture potential and its balancing components, because crops only benefit from transpiration sharing. The soil moisture potential, which governs the movement of soil moisture based on differential energy states, is a significant factor. In general, the kinetic energy of a soil moisture flow rate is too tiny to be taken into account. Due to its location in a force field that may help to increase water use efficiency, the corresponding potential energy of soil moisture is what defines its energy state. Significant irrigation water loss happens during flood irrigation through evaporation, seepage or drainage. On the other hand, tensiometer-based soil moisture potential delineation contributes significantly to irrigation water savings. Therefore, having greater yield potentials as well as improved lives in water-stressed regions of the world requires a proper understanding of soil moisture potentials, its components, and their relationship with soil water flow for reducing water footprints particularly of water stressed regions.

The environmental impact of beef and ultra-processed food consumption in Brazil.

This study evaluated the independent and combined environmental impacts of the consumption of beef and ultra-processed foods in Brazil. Cross-sectional study. Brazil. We used food purchases data from a national household budget survey conducted between July 2017 and July 2018, representing all Brazilian households. Food purchases were converted into energy, carbon footprints and water footprints. Multiple linear regression models were used to assess the association between quintiles of beef and ultra-processed foods in total energy purchases and the environmental footprints, controlling for sociodemographic variables. Both beef and ultra-processed foods had a significant linear association with carbon and water footprints (P < 0·01) in crude and adjusted models. In the crude upper quintile of beef purchases, carbon and water footprints were 47·7 % and 30·8 % higher, respectively, compared to the lower quintile. The upper quintile of ultra-processed food purchases showed carbon and water footprints 14·4 % and 22·8 % higher, respectively, than the lower quintile. The greatest reduction in environmental footprints would occur when both beef and ultra-processed food purchases are decreased, resulting in a 21·1 % reduction in carbon footprint and a 20·0 % reduction in water footprint. Although the environmental footprints associated with beef consumption are higher, dietary patterns with lower consumption of beef and ultra-processed foods combined showed the greatest reduction in carbon and water footprints in Brazil. The high consumption of beef and ultra-processed foods is harmful to human health, as well as to the environment; thus, their reduction is beneficial to both.

Water Footprint of Animal Breeding Industry and Driving Forces at Provincial Level in China

Agriculture significantly contributes to the global water footprint (WF) with the animal breeding industry accounting for over 33% of agricultural water consumption. Since 2000, rapid development in animal breeding has intensified the pressure on water resources. Forecasts indicate a projected 70% increase in freshwater usage in the meat industry by 2025 compared to 2000, particularly in developing countries, such as China, yet comprehensive studies regarding China’s animal breeding industry WF remain limited. This study aimed to assess the variations in the green, blue, and gray WF of pork, beef, milk, eggs, and chicken meat across 31 provinces in China from 2000 to 2017. Additionally, a driving force analysis using the Kaya equation and LMDI method was conducted. Findings revealed that the total WF of animal products increased from 1049.67 Gm3 (in 2000) to 1385.05 Gm3 (in 2017) in China, and pork exhibited a significantly higher WF compared to other animal products, contributing 64.49% to China’s total animal product WF. The sharp rise in the green WF demonstrated regional disparities in water consumption efficiency within the animal breeding industry. The increase in the blue WF was associated with rising livestock numbers and China’s efforts to conserve water. The increase in the gray WF indicated that increased consumption of animal products heightened wastewater treatment pressures, particularly in economically developed provinces. The augmentation in China’s animal product WF was primarily influenced by policy and economic effects, with increased agricultural equipment funding and enhanced production efficiency identified as effective strategies for WF reduction. This study suggests that the promotion of technology, combined with scientific policies, can alleviate the pressure on water resources in the animal breeding industry in developing countries.

Simulation study on the effect of differentiated carbon tax adjustment on CO2 emissions reduction in China from the perspective of carbon footprint

The carbon tax is an efficient environmental and economic method for lowering CO2 emissions, and effective carbon taxes should not only aim to reduce CO2 emissions but also consider their impact on socio-economic and resource utilization. The carbon footprint reflects actual carbon emissions and trade connections between sectors, providing a reference for levying carbon taxes on different sectors and examining their impact on the economy. This study utilizes the 2017 non-competitive input-output table of China and CO2 emissions and water consumption data from 27 sectors. Firstly, the research calculates carbon and water footprints of each sector through input-output analysis. Then, utilizing the input-output price model, the article compares the effect of differentiated carbon taxes on CO2 emissions and GDP across sectors in China, examining both direct carbon emissions and carbon footprint. Lastly, the survey constructs a carbon tax optimization model, aiming to maximize carbon and water footprint reduction while minimizing reduction in labor compensation. The key findings are: (1) Different sectors display varying characteristics in terms of direct carbon emissions and carbon footprints. 19 sectors exhibit higher direct carbon emissions than carbon footprints, while 8 sectors show the opposite. (2) Implementing carbon taxes on all sectors in China based on direct carbon emissions and carbon footprints effectively reduces CO2 emissions. However, at the same tax revenue, a reduction of 10^4 yuan in GDP leads to a further decrease of 0.47 × 10^6 tons of CO2 emissions from the carbon footprint perspective compared to direct carbon emissions. (3) In the optimal differentiated carbon tax plan based on carbon footprints, water production sector bears the highest carbon tax at 5.45 yuan/ton, while electricity production sector bears the lowest at 0.1 yuan/ton. This plan declines CO2 emissions by 7.82% and water consumption by 6.21%, but also results in a 0.02% decrease in GDP. The research findings recommend that sectoral differentiated carbon taxes consider economic development and resource impacts. Implementing refund policies to compensate for the economic losses caused by carbon taxes is essential, while also conserving resources and reducing CO2 emissions. These recommendations provide valuable guidance for the future introduction and implementation of differentiated carbon tax policies.

Revealing the changes in water footprint at the provincial level and their drivers in the Yellow River Basin, China

Water scarcity has become the most significant limiting factor for sustainable economic and social development in the Yellow River Basin (YRB). Despite this, most current studies on water resources in the YRB from a water footprint (WF) perspective have focused on WF measurements and have explored the influencing factors of WF changes in certain industries, while the impact mechanisms driving regional WF changes remain unclear. To bridge this research gap, the WF of nine provinces in the YRB for 2012 and 2017 were quantified using an environmentally extended multi-regional input-output model (EE-MRIO), and the driving forces of regional WF changes were explored via structural decomposition analysis (SDA). The results showed that the WF of the YRB increased by 3.8% to 113.64 billion m3 between 2012 and 2017. With rapid economic development and enhanced inter-regional trade links, the external WF has played an important role in meeting local water demand. Technological advances and production structure adjustments contribute to the reduction of the WF, thus promoting the sustainable use and management of the YRB’s water resources. Both consumption patterns and final demand per capita have dominated the YRB’s WF growth, particularly in the economically developed middle and lower reaches, where urban household consumption drove the largest WF, accounting for over 40%. Therefore, in the future, continuous optimization of the consumption structure and guidance of green consumption awareness are expected to contribute more to the reduction in WF. The findings of this study reveal the primary causes of WF changes in the YRB and offer a theoretical justification for the formulation of water conservation and sustainable utilization policies.

Optimizing crop production water footprints in the face of water scarcity: a combined experimental and simulation study of wheat in Zimbabwe

Abstract The optimization of water footprints in crop production is critical, given that agroecosystems currently account for more than 70% of global freshwater use. To achieve this, crop growth models provide insights into the impact of various crop and irrigation management strategies on both crop productivity and water use. This study evaluated the capability of the AquaCrop model in simulating wheat yields, crop water use, and water footprints in the Middle-Manyame Sub-Catchment, Zimbabwe. The model was calibrated and validated using experimental data collected from field experiments. Simulation experiments were conducted to assess the impact of early and late planting, drip and sprinkler irrigation techniques, and no mulch, organic mulch, and synthetic mulch options on the water footprint (WF). The AquaCrop model accurately simulated soil water content, crop water use, crop biomass, and grain yield. Simulation runs showed that early planting reduced WFblue and WFgreen by 25 and 4%, respectively. The lowest consumptive WF was observed with drip irrigation and synthetic mulching. The greatest decline in WFblue and WFgreen (52 and 11%) was simulated under early planting, using drip irrigation and synthetic mulching. Overall, the study highlights the importance of efficient crop and irrigation management practices to reduce water footprints in agroecosystems.

A water-absorbent hydrogel prepared with arabinoxylans from flaxseed (Linum usitatissimum) and galactomannans from subabul (Leucaena leucocephala) impacts the growth and composition of cherry tomatoes in potted experiments

A water-absorbent hybrid hydrogel was prepared using arabinoxylans from flaxseed (Linum usitatissimum) (FX) and galactomannans from subabul (Leucaena leucocephala) (SG) in the presence of kappa-carrageenan (κC) with variable concentration of potassium chloride as crosslinker (0.01, 0.05, 0.1, 0.25 and 0.3 M), and evaluated on the basis of their swelling rate (%). The optimized hydrogel (GAXH) from a blend of SG, κC, FX and KCl at 5.5% w/v, 1.32% w/v, 1% w/v and 0.3M, respectively, showed 300% swelling in water at room temperature and pH 7.4 with 100% retention of water for 30 days at 10 °C. Blending 50% w/w GAXH in the soil could retain 140% water for 30 days, acting as a water reservoir in the soil system at 35 °C and pH 7.4 which reached 100% evaporation after 60 days. Incorporation of 50% w/w GAXH in sandy, loamy soil was used for the potted cultivation of cherry tomatoes (Solanum lycopersicum var. cerasiforme) and observed for growth and composition of the tomatoes. GAXH enhanced the physiological growth of both the plant as well as cherry tomatoes by controlling the release of KCl into the soil and maintaining soil moisture when 3 day intermittent watering schedule was used. An additional advantage was an improved water use efficiency and reduction in water footprint from 3.23 cm3/g to 9.32 cm3/g and 19.87 mL/fruit to 8.56 mL/fruit, respectively. The fully ripened tomatoes grown on GAXH-incorporated soil showed higher contents of lycopene, total carotenoids, and total polyphenols from 166 to 257 μg/g fresh weight, 99–107 mg β-carotene equivalent/100g fresh weight, 223–241 mg gallic acid equivalent/100 g fresh weight, respectively, than control cherry tomatoes grown in soil with no added GAXH. This was also reflected in enhanced antioxidant activity of cherry tomatoes grown in GAXH-incorporated soil.

Components and drivers of household water footprint inequality in China

A comprehensive investigation of household water footprint inequality components and internal drivers is the prerequisite for equal water availability. This paper applied the input-output model to depict household blue and grey water footprint and decomposed the sources of household water inequality and the internal drivers of its changes in China from 2002 to 2012. Results indicated that the average household water footprint has decreased by about 8.52 %, mainly due to the reduction in household direct grey water footprint during the period. Household grey water footprint is distributed more unevenly in households, and indirect grey water footprint from food, clothing, and residence composed more than 80 % of the overall inequality. From 2002 to 2012, the household water Gini coefficient increased from 0.285 to 0.286. The structural changes in household water footprint offset most of the increasing pressure caused by the actual inequality changes in household water footprint. Specifically, structural changes in household water footprint from “necessities” made the overall inequality decrease by 0.015, while the “luxury” counterparts made a positive contribution by 0.009. Notably, clothing, and transport and communication services contributed most to the overall inequality increase, most of which is neutralized by that from residence.

Impact of irrigation management on crop water footprint reduction using RZWQM2 in Baghdad, Iraq

Water scarcity becomes a serious global challenge in several world regions and particularly in the Middle East. Appropriate irrigation practice is critical for improving crop yield and alleviating crop water footprint (WF). To alleviate water scarcity, the possibility of reducing wheat and barley water footprint has been examined through alternative surface irrigation practices. The WF was compared under farmers’ irrigation practice and experimental irrigation practice to discover the impact of irrigation practices on the reduction of WF in the west of Baghdad. Weather data and crop management information were collected from 2016 to 2020 for the farmer’s fields in the study area as well as for the experimental field. The Root Zone Water Quality Model (RZWQM2) was used for estimating wheat and barley evapotranspiration. The study results showed that the crop WF was well estimated using the RZWQM2 due to the model capability and accuracy for estimating the impact of field management on crop evapotranspiration and crop water use. Experimental irrigation practice could improve crop yield, water use efficiency, and water profitability by up to 28%, 35%, and 35%, respectively; while the WF was reduced by 35%, compared to the farmers’ irrigation practice. The WF of the wheat crop was lower than the barley WF due to the low barley production.

Are advertising campaigns for water conservation in Latin America persuasive? A mixed-method approach

The United Nations 2030 Agenda for Sustainable Development calls for an urgent reduction of global water footprint. Communication is crucial to respond to this call. However, most water conservation communication campaigns use the knowledge deficit model and overlook persuasive techniques. This paper presents a mixed-method approach consisting of exploratory sequential qualitative (content) analysis followed by a quantitative (cluster) analysis. This approach was used to explore the communication strategies of 95 advertisements promoting water conservation in Latin America. Four widely used persuasion frameworks were analyzed: (1) the elaboration likelihood model (ELM), (2) prospect theory (gains vs. losses), (3) the action framework (i.e., do more vs. take less), and (4) the temporal distance frame. Regarding persuasive characteristics (ELM model), most ads excluded behavioral beneficiaries (58%) and included explicit (60%) and active (52%) messages. Virtually all ads (87%) had a denotative message. Surprisingly, only 3% and 43% of ads used social norms and an authority source, respectively. Regarding the communication strategy, 44% of ads used a loss frame, and 59% focused on the current generation. Cluster analysis was used to classify the sample of ads into homogeneous groups. This analysis leads to a better understanding of the profile of campaigns promoting water conservation. Four advertising profiles were identified: (1) Persuade to act (29%), (2) Motivate without scaring (35%), (3) Raise awareness of water problems (19%), and (4) Warn of water problems (17%). The paper offers a discussion of the implications for social marketers and directions for future research on how to design effective communication campaigns.

Process analysis and mitigation strategies for wetland degradation caused by increasing agricultural water demand: an ecology–economy nexus perspective

BackgroundFarmland expansion has played a major role in wetland degradation in Heilongjiang Province, China in recent decades. Farmland expansion increases the demands for water, thereby affecting wetland water cycles, and promoting the shrinkage of wetland areas and degradation of ecosystem functions. As an open system, agricultural production is limited by both ecological and socioeconomic conditions. However, our understanding of wetland degradation caused by farmland expansion from the perspective of the ecology–economy nexus is limited.MethodsA correlation between farmland expansion and agricultural economic activities was established, and wetland degradation driven by agroeconomic activities was inversely derived using a multi-regional input–output (MRIO) analysis. We developed an ecology–economy nexus framework to explore the ecological process of the area and water demand tradeoffs between wetland degradation and farmland expansion, the economic process of wetland degradation driven by food consumption, and the nexus between the two processes. We finally explored strategies to mitigate wetland degradation due to increased agricultural water demand.ResultsFarmland expansion contributed to 93.76% of the total degraded wetland area. There was a significant negative correlation between wetland area and the water consumption for crop production, but no significant correlation between wetland area and the ecological footprint of croplands. The direct wetland degradation caused by local final demand accounted for 63.02%, while the indirect degradation caused by non-local final demand accounted for 36.98%. Hebei, Shandong, Liaoning, Inner Mongolia, and Shanghai were the top five provinces contributing to indirect wetland degradation in Heilongjiang. Our findings indicated that a mixed scenario combining water footprint reduction per unit yield with food export reduction could maximize wetland restoration while reducing local farmland–wetland competition for water.ConclusionsOur research highlights the effects of economic processes in the agricultural sector on wetland degradation, and showed that the adjustment of food trade patterns can effectively promote wetland restoration.

Multi-model assessment identifies livestock grazing as a major contributor to variation in European Union land and water footprints

Food systems are the largest users of land and water resources worldwide. Using a multi-model approach to track food through the global trade network, we calculated the land footprint (LF) and water footprint (WF) of food consumption in the European Union (EU). We estimated the EU LF as 140–222 Mha yr−1 and WF as 569–918 km3 yr−1. These amounts are 5–7% of the global LF and 6–10% of the global WF of agriculture, with the EU representing 6% of the global population. We also calculated the global LF of livestock grazing, accounting only for grass eaten, to be 1,411–1,657 Mha yr−1, and the global LF of agriculture to be 2,809–3,014 Mha yr−1, which is about two-thirds of what the Food and Agriculture Organization Statistics (FAOSTAT) database reports. We discuss here the different methods for calculating the LF for livestock grazing, underscoring the need for a consistent methodology when monitoring the food LF and WF reduction goals set by the EU’s Farm To Fork Strategy.

The evaluation of menus’ adherence to sustainable nutrition and comparison with sustainable menu example in a Turkish university refectory

Purpose It is very crucial to evaluate the suitability of food services from an environmental and economic point of view to design sustainable food menus. This study aims to analyse the food menus in a Turkish university refectory concerning sustainable nutrition and waste management and compare them with a proposed sustainable food menu. Design/methodology/approach The study examined lunch menus served in December and February 2021–2022 at Istanbul Medipol University refectory for a total of 20 days, considering the nutrient-rich food index (NRF 9.3), waste amount, food cost, water and carbon footprint parameters of the meals. Findings Comparing the December menu with the suggested sustainable December menu showed a significant reduction in carbon and water footprint (p = 0.001), food cost (p = 0.001) and NRF 9.3 score (p = 0.001). When February and the suggested sustainable February menu were compared, there was a significant decrease in carbon and water footprint (p = 0.001), food cost (p = 0.005) and NRF 9.3 score (p = 0.001). December and February menus had higher NRF 9.3 score compared to the sample sustainable menus, and the amounts of saturated fat, added sugar and sodium were also high in these menus. Originality/value The study revealed that university cafeteria menus are incompatible with sustainable nutrition. The findings can significantly contribute to improving the sustainability of meals and food services by minimizing the water and carbon footprint of menus.

Economic Feasibility and Water Footprint Analysis for Smart Irrigation Systems in Palm Oil Industry

The Malaysian palm oil industry is the second largest global producer of palm oil products in the world after Indonesia. However, oil palm plantation activities are typically very labour-intensive and inefficient. The rapid development of technologies, especially Industry Revolution 4.0 technologies, has brought forward a variety of advanced smart technologies and systems that can be adapted in the palm oil industry to improve the efficiency and yields in the industry as well as create better economic performance. This work aims to explore and quantify the potential of adaption and implementations of smart irrigation system in oil palm plantations. The proposed approach considers economic performance (return of investment, ROI) and water footprint (additional water usage) of smart irrigation. In addition, the analysis also includes the consideration of different server setup options and plantation sizes. The results show that smart irrigation is a feasible method to be implemented in oil palm plantations with positive economic performance for plantation with land size more than 1.5 ha. The findings also show a significant reduction in water footprint and costs in the smart irrigation system to achieve optimal moisture conditions in a plantation. This paper provides insight for oil palm stakeholders to understand the feasibility and performance of smart irrigation systems as a feasible option to transform oil palm plantations with Industrial Revolution 4.0 technologies.

Comparing water related indicators and comprehensively evaluating cropping systems and irrigation strategies in the North China Plain for sustainable production

The fully irrigated winter wheat–summer maize double cropping system (DWM) has caused groundwater overexploitation and aggravated water scarcity in the North China Plain (NCP). Therefore, it is necessary to select alternative cropping systems with effective irrigation strategies to maintain the sustainable use of groundwater and maintain crop productivity. However, the evaluation indicators, especially the water-related indicators of cropping systems and irrigation strategies in current studies are not consistent and it is difficult to obtain a comprehensive evaluation result. Hence, to overcome these challenges, this study reviewed and compared groundwater indicators, water use indicators, water production performance indicators and output indicators, and summarized twelve evaluation combinations. Four evaluation combinations with grain yield as output indicator were selected to comprehensively evaluate the cropping systems and irrigation strategies developed by Agricultural Production Systems sIMulator (APSIM) at a typical site in the NCP in the past 52 years. The indicator weights were determined by analytic hierarchy process, entropy weight method, random forest algorithm and principal component analysis. Evaluation results showed that when the main goal was to guarantee food safety or improve the beneficial water use, the DWM was selected as the best choice and the WMM (winter wheat–summer maize → spring maize system, three crops in two years) was the alternative cropping system. Under this condition, water saving irrigation should be vigorously developed to reduce groundwater exploitation. When the four indicator types had the same weight, the DWM under rainfed was the best choice to improve evapotranspiration use efficiency and precipitation use efficiency; the monocropping spring maize system under normal irrigation strategy was the best choice to reduce water footprint. The WMM under rainfed was the alternative choice to improve evapotranspiration use efficiency, improve precipitation use efficiency and reduce water footprint. The evaluation methods proposed in this study could be used as reference in the comparison of cropping systems and irrigation strategies in other water-related situations.

Climate-smart technologies for reducing water footprints in different cropland ecosystems: a meso analysis

Water footprints (WFs) in crop production are an ecological measurement of water utilization that represents the cumulative groundwater quantum consumed within a region (district/state or country) to produce the crops. WFs in crop production have great significance for ecosystem’s sustainability, as high WFs are posing a serious challenge for the scientists and presents researchable issues for reducing WFs for increased crop water productivity. Crop need based approaches and improved climate smart technologies (CSTs) instead of conventional approaches help in reducing the irrigation water use without compromising crop yields. In view of global warming, need to reduce the water intake in agricultural production has been thought as an urgently sustainable issue. Amongst various crops of South Asia, rice–wheat cropping system extensively cultivated on ~ 12.5 million ha (Mha), has large WFs. A large scale field experimentation suggested several permissible techniques having overwhelming significance for reducing WFs in crop production. Amongst the several CSTs, laser levelers for precision leveling, cultivars with short duration rice varieties, delayed transplanting of rice seedlings, soil matric potential (or tensiometer) based irrigation scheduling, direct drilling of rice seeds, crop establishment on permanent beds, mechanical rice seedling transplanting, and crop diversification through oilseed/pulses has considerable significance in water saving and decreased WFs. Nonetheless, all technologies are not universally efficient in reducing WFs, and depend up on several factors of which soil texture and climatic conditions are the major determinants. For feeding the burgeoning population and to sustain and/or increased food production, technological focus should be on widespread adoption of technologies which aims at reduced WFs either by decreasing water loss from the leaf and/or soil. The present review deals with WFs in crop production, and the technologies to enhance irrigation water productivity and ecosystems’ sustainability of predominant cropping system of South Asia, particularly in water-harassed regions.