Water-saving Technologies Research Articles

Technology of high-yield cultivation by planting a new variety of mung bean to improve land reclamation condition, increase its productivity, and ensure ecological stability

It is important to plant new early varieties of mung bean from leguminous crops in irrigated lands. These crops create very favorable conditions for the crops that will be planted after them. In the year following the planting of the new “Charos” variety of intensive mung bean, an additional yield of 5-7 q/ha of cotton and 7-9 quintals of grain was achieved. Therefore, when mung bean is planted as a repeated crop, the weeds in the field are reduced by 70-80 percent, while ensuring the enrichment of the soil with nutrients. In the autumn, when mung bean fields are plowed up by roots, soil fertility increases and the structure improves, as a result of raising the level of underground water to the optimal level, i.e. 2.5-3.0 meters, it was found that water-saving technologies can be widely used in planting agricultural crops. In the soil and climatic conditions of the Bukhara region, when the intensive type of mung bean “Charos” is planted, the full germination period is 5 days earlier than the Local (control) variety, 4 days compared to the Radost variety, and 3 days earlier than the Navruz variety and ripened 10-15 days earlier than Local (control), Radost, Navruz varieties. Productivity was on average 28-30 quintals per hectare, which was 6-9 q/ha more than other varieties. When this variety is planted, the stem is resistant to lying down, and until harvesting, the pods do not crack and the grain does not spill, it is very convenient to harvest with combines. For 2-3 years after planting mung bean, the use of chemical fertilizers is reduced by 25-30%, which ensures the stability of the environment and production of a clean product.

Subsurface irrigation with ceramic emitters: Optimal working water head improves yield, fruit quality and water productivity of greenhouse tomato

Greenhouses are widely used in Northwest China, especially for tomato, which is the dominant crop. Subsurface irrigation with ceramic emitters (SICE) is a new water-saving technology for continuous low-rate water supply at constant soil moisture. However, a lack of knowledge still existed to define the suitable working water head for SICE to decrease water loss and promote tomato production, fruit quality, and water productivity. In this study, a greenhouse experiment was conducted during spring and autumn cultivation periods under SICE for five working water heads of 0.1 m to 0.5 m with intervals of 0.1 m and subsurface drip irrigation (SDI). The verified HYDRUS-2D model evaluated water balance components and water productivity. A structural equation model (SEM) was developed to determine interactive impacts of SICE and meteorological conditions in greenhouse on tomato yield, fruit quality, and water productivity. The results showed that SICE with a working water head of 0.4 m could be recommended, which created a suitable soil water content of the root zone within 70%–80% of field capacity (FC), resulting in a reduction of water loss from actual evaporation (Ea) and deep percolation (DP) by 12.32% and 21.88% respectively relative to SDI. Fruit weight, yield, water use efficiency (WUE), and irrigation water use efficiency (IWUE) were increased by 8.96%, 8.03%, 19.44%, and 16.05% respectively compared to SDI. Moreover, soluble sugar, organic acid, lycopene, vitamin C, and sugar acid ratio were enhanced by 2.41%, 12.19%, 14.40%, and 2.67% under SICE with the suggested working water head respectively compared with SDI. We recommended that supplemental lighting combined with SICE in autumn cultivation was necessary to ensure tomato production and fruit quality. This study provides an alternative water-saving irrigation method for greenhouse growers to maintain tomato yield and fruit quality in Northwest China.

Testing the Effects of Water-Saving Technologies Adapted to Drought: Empirical Evidence from the Huang-Huai-Hai Region in China

The aggravation of extreme weather events has dramatically increased the risk of severe water shortages and seriously threatened agricultural production. The Huang-Huai-Hai region, an important agricultural production region in China, is subject to a severe water shortage and is often hit by drought. As a result, water-saving technologies (WSTs) have been implemented. It remains unclear how effectively these WSTs can reduce crop yield loss, crop yield variation, and the loss of net crop income caused by water scarcity. Therefore, this paper aimed to analyze the role of WSTs in response to drought by establishing a multi-objective expected utility function based on 988 farmers across the Huang-Huai-Hai region. Econometric analysis employing an endogenous switching regression model showed that using WSTs can significantly reduce crop yield loss and net income loss caused by drought. Adopting household-based WSTs or community-based water-saving technology generates even greater positive effects on crop yield and farmers’ net income. Therefore, the government should promote farmers’ adoption of more advanced WSTs by increasing subsidies and strengthening policy support.

Opportunities for Implementing Closed Greenhouse Systems in Arid Climate Conditions

The closed greenhouse is an innovative crop system in the horticulture sector, integrating appropriate climate control equipment and optimized techniques to collect, store, and reuse solar energy for heating and/or cooling the greenhouse. This concept aims to improve the crop yield and quality with energy efficient and water-saving technologies. A specific focus on the opportunities of implementing closed greenhouses under arid climate conditions is detailed in this work. Guidelines for selecting appropriate techniques and design parameters are investigated, aiming for profitable and sustainable greenhouse production. This paper provides an overview of the design aspects of the closed greenhouse and a state of the art of its applications in arid areas. Firstly, the microclimate parameters, including temperature, relative humidity (RH), light intensity, and CO2 concentration are introduced. Then, an in-depth focus on the effects of these parameters on crop productivity, water, and energy efficiency are thoroughly discussed. Finally, the limitations of closed greenhouse applications are pointed out as opportunities for further research and development in this emerging agriculture field.

Toward near-zero water consumption grade labelling and evaluation benchmarks for residential buildings

ABSTRACT Mitigating global warming and climate change has become a crucial mission for sustainable development all over the world. This research focus on the feasibility of development near-zero water consumption buildings. The water saving motivation is necessary to be raised by a clear measurement basis for the rational water use of buildings and encourage more efforts to improve building water-use efficiency.A water conservation benchmarks and grade labelling assessment system for residential buildings had been established. We concluded a simplified and reliable building water evaluation method for implementation in residential buildings. Meanwhile, this study investigated the actual water consumption data of existing buildings in Taiwan, analyzed the water consumption intensity per unit area of residential buildings, and grasped a reasonable and precise benchmark for building water consumption. The water consumption intensity per building area was analyzed to verify the theoretical water consumption estimation method. Eventually, we summarized the annual average benchmark and graded labelling system of domestic water consumption for individual residential building evaluations. Furthermore, this study integrated Taiwan’s green building labeling system and carbon reduction evaluation system with water-saving technology, which was anticipated to target the development of near-zero water consumption buildings.

Analysis of the Application of Energy-saving and Water-saving Technology in Building Water Supply and Drainage Engineering

Analysis of the Application of Energy-saving and Water-saving Technology in Building Water Supply and Drainage Engineering

Alternate wetting and drying modulated physio-biochemical attributes, grain yield, quality, and aroma volatile in fragrant rice.

Alternate wetting and drying (AWD) has been recognized as a water-saving technology in rice production systems; however, pre- and post-flowering AWD could induce changes in yield, quality and aroma biosynthesis in fragrant rice. In the present study, two fragrant rice cultivars (Guixiangzhan and Nongxiang-18) were subjected to AWD till soil water potential reached -25 to -30 kPa during vegetative stage (VS), reproductive stage (RS), and both stages (VS + RS). The AWD did not affect net photosynthesis and gas exchange significantly, while malondialdehyde (MDA), H2 O2 and electrolyte leakage (EL) were higher than in control plants. The AWD treatments variably affected soluble sugars, proline and protein accumulation as well as the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and reduced glutathione (GSH) contents. Moreover, filled grain percentage and 1000-grain weight in AWD treatments were found to be statistically similar (p > 0.05) to control, except grains panicle-1 under AWD-VS + RS that was reduced by 11% and 14% for Guixiangzhan and Nongxiang-18, respectively. On average, yield and related attributes in Guixiangzhan remained higher than in Nongxiang-18. In addition, the grain aroma volatile (2-acetyl-1-pyrroline, 2-AP) content increased by 8.79%, 14.45%, and 6.87% and 7.95%, 14.02%, and 5.04% under AWD-VS, AWD-RS, and AWD-VS + RS treatments, for Guixiangzhan and Nongxiang-18, respectively. Overall, AWD treatments, either at VS or RS, could promote rice aroma in terms of accumulation of 2AP, which might be linked with enhanced endogenous proline contents (a precursor for 2AP biosynthesis) without any severe consequences on rice yield and quality.

Adoption of Sustainable Agriculture Practices through Participatory Research: A Case Study on Galapagos Islands Farmers Using Water-Saving Technologies.

Agriculture in the populated islands of the Galapagos Archipelago, a protected area due to its unique biodiversity, has been detrimental to its conservation but highly required to meet food necessities. A potential solution to make agricultural farming more sustainable is adopting water-saving technologies (WSTs). Therefore, this study aimed to test the effectiveness of using WSTs such as Groasis Waterboxx® in three of the most valuable crops in the islands through participatory research with the involvement of a group of farmers from the Floreana and Santa Cruz islands and explore a possible transition to more sustainable agricultural practices. Capsicum annuum, Cucumis sativus and Solanum lycopersicum were cultivated using Groasis Waterboxx® and compared to conventional irrigation practices (drip-irrigated controls) to assess the variability of productivity, the number of fruits and individual fruit weight (IFW). In addition, differences in plant traits were analyzed by crop, and island. Results suggested that WSTs such as Groasis Waterboxx® may provide on-farm benefits regarding the yields of the studied traits. From this study, it is difficult to determine whether participation in such a research study will permanently change irrigation practices. However, the participant's responses to the study suggest an increase in their understanding of the use and benefits of WST.

Does agricultural water conservation policy necessarily reduce agricultural water extraction? Evidence from China

Does the implementation of agricultural water conservation policy necessarily bring about a reduction in agricultural water extraction? Taking China's National Agricultural Water Conservation Outline proposed in 2012 as an example, this paper uses the data of 31 provinces from 2000 to 2019, and employs an empirical strategy of Difference-in-Differences (DID) to estimate the impact of the agricultural water conservation policy on agricultural water extraction. The results show that the agricultural water conservation policy does not achieve the decline of agricultural water extraction, but increases agricultural water extraction. When addressing contemporaneous water-related policies or estimating in subsample, these results are robust. The possible reason for this phenomenon is that the agricultural water conservation policy promotes agricultural production, especially by increasing the sown area and irrigated area, and the expansion of irrigated area is the main reason for the increase in agricultural water extraction. Moreover, land potentiality for crop production may affect the water-saving effect of the agricultural water conservation policy, in which provinces with higher land potentiality will have less increase in agricultural water extraction caused by the agricultural water conservation policy. Therefore, with the empirical evidence from China, agricultural water conservation policy may not necessarily reduce agricultural water extraction, and this phenomenon is always regarded as rebound effects. In order to avoid the adverse impacts of the rebound effect, agricultural water-saving technologies can be strengthened in areas with high land potentiality for agricultural production, and market-oriented policies, such as water rights reform, can be employed to avoid excessive use of water resources in areas with severe over-extraction.

A Study on Spatial-Temporal Differentiation and Influencing Factors of Agricultural Water Footprint in the Main Grain-Producing Areas in China

It is an urgent scientific issue to explore the spatial and temporal differentiation and impact indicators of the agricultural water footprint in major grain-producing areas. Therefore, this study tries to use the water footprint theory to implement top-down calculation of the agricultural water footprint in major grain-producing regions from 2000 to 2019 and investigate the various impacts on the agricultural water footprint under the influence of spatial-temporal effects using spatial autocorrelation and the spatial Dubin model. The results indicate that from 2000 to 2019, the overall agricultural water footprint of China showed a fluctuating downward trend in an inverted N shape and demonstrated high–high and low–low spatial aggregation characteristics. There are notable characteristics, including high spatial dependence, spatial barriers, and path locking of the agricultural water footprint in most provinces and regions of the main grain-producing areas. Policy factors, water-saving technologies, social development, economic development, and industrial structure adjustment are all significantly and negatively correlated with the increase in the agricultural water footprint, while agricultural production and natural factors have a significant positive relationship with the agricultural water footprint. The spatial spillover effect of water-saving technologies, industrial restructuring, agricultural production, and natural factors is powerful. Therefore, a rationally optimized industrial structure, strengthened regional linkage of water resources management and control, and the promotion of efficient water infrastructure technology are important ways to inhibit the agricultural water footprint.

Can additional agricultural resource inputs improve maize yield, resource use efficiencies and emergy based system efficiency under ridge-furrow with plastic film mulching?

Water scarcity is a major constraint for maize production in drylands. As an efficient water-saving technology, the ridge-furrow with plastic film mulching (RM) system has achieved success in dryland farming. The efficiency of the rainwater-harvesting system in RM is greatly affected by erratic precipitation, and water absorption by crops is influenced by nutritional availability. Whether the additional supply of irrigation and nitrogen (N) resources under the RM system could influence the resource use efficiencies, emergy flows, and system efficiency of agricultural products is unclear. Therefore, a 3-year field study on maize plants consisting of four planting patterns (CP: conventional planting; RM; RM + SI: RM plus supplementary irrigation; RM + SI + N: RM + SI plus additional N fertilizer) was conducted from 2018 to 2020 in the Loess Plateau of China to determine resource use efficiencies, emergy flows, and system efficiency through emergy evaluation. In this study, we demonstrated the high efficiency of the micro-field rainwater-harvesting system of RM by collecting more rainwater and improving soil hydrothermal conditions. For example, the soil temperature and moisture of topsoil at seedling stage were increased by 4.3 °C and 13%, respectively, under RM compared with CP. The soil hydrothermal conditions in RM further improved maize yield (+35%), water use efficiency (+32%), N partial factor productivity (+37%), radiation use efficiency (+10%), and system efficiency (8%, from an emergy perspective), compared to CP. However, the additional supply of N or irrigation in RM + SI or RM + SI + N planting patterns failed to increase resource use efficiency, although the maize yield was increased by 9%. Furthermore, although the total emergy input was increased by 19%, it did not significantly increase energy output, and thus decreased the resource efficiency by 9% through emergy evaluation, compared to RM. Overall, RM without additional agricultural resource input could be recommended as a sustainable and cleaner production strategy for maize in drylands to address the issues of ever-increasing food demand and declining availability of production resources.

Acid-modified biochar increases grain yield and reduces reactive gaseous N losses and N-related global warming potential in alternate wetting and drying paddy production system

Biochar amended soils reduce fertilizer N losses and suppress greenhouse gas emissions. However, biochar can increase NH3 volatilization. H2SO4- modified biochar has been studied as a means to achieve the advantages of biochar while reducing volatilization, especially under alternate wetting and drying irrigation (IAWD). In contrast to continuously flooded irrigation (ICF), IAWD is a water-saving technology that repeatedly dries and re-floods fields. A 3-year field experiment was conducted with two irrigation regimes (ICF and IAWD) as main plots and 0 (control), 20 t ha−1 biochar, and 20 t ha−1 H2SO4-modified biochar as subplots. IAWD produced 7.6–14.8% more reactive gaseous N losses (NH3 and N2O) and emitted 2.02 times N-related global warming potential (GWPN) of ICF. Biochar increased NH3 volatilization by 35.6% in the first year and decreased it by 22.4% and 24.8% in the second and third years, respectively, while H2SO4-modified biochar decreased NH3 volatilization each year. The increased NH3 volatilization was caused by the higher NH4+ concentration and pH in the floodwater and surface soil due to increasing N inputs and alkalinity from biochar. The decrease in the following two years was attributed to pH returning to the pre-treatment level and continued biochar absorption of NH4+ from the floodwater. Both biochar and H2SO4-modified biochar significantly reduced seasonal N2O emissions. H2SO4-modified biochar coupled with IAWD mitigated the initial increases in NH3 volatilization and reactive gaseous N losses in the first year, and increased grain yield, decreased reactive gaseous N losses, and GWPN compared with the IAWD without biochar throughout the three years. The use of acid-modified biochar could produce higher grain yield with lower reactive gaseous N losses and GWPN for application in the IAWD paddy systems, which benefits sustainable agricultural production.

Comprehensive improvement of soil quality and rice yield by flooding-midseason drying-flooding.

Many water-saving technologies have been developed to reduce water input and the associated irrigation costs. However, the influence of water management technologies on soil quality is unclear. Soil quality is fundamental to rice yield and sustainable productivity of ecosystems. Therefore, it is important to understand the effect of water management on soil quality and its linkage with rice yield. In this work, a field experiment was conducted to assess the influence of water management on soil physico-chemical properties, microbial biomass, bacterial community, and rice yield in paddy fields. Three water treatments were selected for the study, including flooding-rain-fed (F-RF), flooding-midseason drying-flooding (F-D-F), and continuous flooding (CF). Total nitrogen (TN), total phosphorus (TP), dissolved carbon content (DOC), available phosphorus (AP), nitrate nitrogen (NO3-), microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN) contents were 11%, 20%, 29%, 30%, 11%, 183%, and 215% higher in F-D-F, respectively, than those in the CF (p < 0.05). Additionally, the bacterial diversity in F-D-F and CF was significantly higher compared to the F-RF (p < 0.05). Correspondingly, soil quality index (SQI) was higher in the F-D-F (0.8) than that of F-RF (0.53) and CF (0.5). Compared with the F-RF, water management remarkably altered bacterial community composition, with higher enrichment of anaerobic bacteria (such as Firmicutes and Chloroflexi) in flooding treatments (CF and F-D-F). Differences in the bacterial community were closely related to key soil quality indicators, such as AP. Parallel increases in soil quality and bacterial diversity resulted in increased rice yield in the F-D-F, which was 53% and 12% higher than that in F-RF and CF, respectively. Therefore, F-D-F is the suggested water management method because it can comprehensively improve soil microbial diversity, soil quality, and rice yield. KEY POINTS: • Water management changed bacterial community mainly via SMC (soil moisture content), TP, AP, and NO3-contents. • The F-D-F had greater SQI and higher rice yield in comparison with F-RF and CF.

Crop Water Requirement and Utilization Efficiency-Based Planting Structure Optimization in the Southern Huang-Huai-Hai Plain

Optimizing planting structure that balances both high yield and water resources shortage is essential for developing efficient water-saving agriculture. To provide insights about the relationship between planting structure optimization and water resource constraint, crop water requirement, precipitation coupling degree, gross total water requirement and irrigation project metrics were calculated and analyzed with the dataset collected from 16 locations in Xuchang City, China. The strategy of reducing the planting proportion of high water-consumption crops and increasing low consumption and high precipitation coupling degree crops was adopted to determine a suitable water-saving planting scheme based on the IQR (interquartile range) method. Evapotranspiration had a decreasing trend from northwest to southeast areas. There were positive correlations between gross total water requirement (GTWR) and annual total yields (r = 0.825, p = 0.002), and between GTWR and proportion of vegetable planting areas (PVPA) (r = 0.734, p = 0.0101). The GTWR was negatively correlated with the ratio of water-saving irrigated areas to effective irrigated areas (RSEA), proportion of wheat planting areas (PWPA) and proportion of bean planting areas (PBPA), with coefficients of −0.787, −0.936 and −0.828, respectively. The planting proportion of winter wheat, summer maize, vegetables and flowers decreased by 8.8%, 25.8%, 16.2%, and 28.7%, respectively, while oil-beans and tubers increased by 62.4% and 95.6%, respectively. The irrigation water consumption was reduced by 5.2%, saving 3.25 × 107 m3 irrigation water without sacrificing economic benefits after adjusting for the whole region. Consequently, precipitation coupling degree, water-saving technology and historical planting habits should be considered when optimizing cropping distributions. This research provided a new theoretical basis and comprehensive approach for agriculture irrigation water management and regional planting structure optimization from a realistic perspective.

Water resources in agriculture of the Republic of Kazakhstan: a view of scientists on rational use, prospects and management

The goal is to study topical issues of development of water resources in agriculture in Kazakhstan. Methods – general scientific: logical, systematic approach, analysis and synthesis, detailing and generalization, comparison, as well as quantitative and qualitative - to assess the effectiveness of the use of water bodies. Results – the causes of water shortage in the republic are determined. Its shortage is influenced by factors such as soil and climatic conditions (on a verage, out of 5 years, 2-3 years are dry), increase of the population (in 2021, compared to 2016, the growth was about 7.0%), uneven distribution of irrigation water by region, reduction of irrigated land under agricultural crops, deterioration of irrigation facilities, lack of reliable collector and drainage networks, pollution of rivers and lakes due to anthropogenic loads. It is proved that the water security of the country depends on the neighboring states – Russia, China, Kyrgyzstan, Tajikistan, Uzbekistan. The results of scientific research of water scientists of the Kazakh National Agrarian Research University on rational management of water sources and transboundary water allocations, consumption of drinking water, expansion of sown areas on artificial irrigation, introduction of water-saving technologies and provision of agricultural land with sprinkling, restor ation of degraded and saline soils, watering of pastures, using the latest digitalization models are presented. Conclusions – according to the authors, it is necessary to develop effective mech anisms for public support of water sectors in Kazakhstan. To solve the above problems, it is necessary to strengthen training of highly qualified personnel capable of searching for and transferring new knowledge, the best innovative projects in the field of the water management complex with their adaptation to local conditions.

Comprehensive Assessment of Plant and Water Productivity Responses in Negative Pressure Irrigation Technology: A Meta-Analysis

Negative pressure irrigation (NPI) is an important water management strategy that can improve crop yields and water use efficiency (WUE). However, because NPI is affected by vital factors, such as negative pressure values, soil properties, and fertilization dosages, there is a lack of systematic analyses of the application effects of NPI on various crops. Hence, this study collected the results of 44 published studies and established the validity of 142 crop yields, 121 WUEs, 138 crop qualities, and 138 crop nutrient statuses in a database for NPI systems. The meta-analysis method was used to analyze NPI in comparison to conventional irrigation (CI) conditions. The results showed that the NPI yields and WUEs significantly improved by 17% and 63% compared to those of CI, respectively. Meanwhile, the negative pressure values were −2~−5 kPa; the improvement effects on yields were the best; and the WUEs exhibited the highest performance with negative pressure values of −6~−10 kPa. NPI promoted crop quality and plant nutrient uptakes under the appropriate NPI conditions. The synergistic impacts for sandy loam, alkalescent soils, and leafy vegetables were greater than for clay loam, neutral soils, and fruit vegetables under NPI conditions. Simultaneously, it was shown that the soil available phosphorus content and application of P fertilizer have a greater impact on NPI and CI crop yields. Therefore, the meta-analysis demonstrated the impacts of NPI on crop yields, WUEs, quality, and nutrient absorption, and quantified the effects of NPI on crop growth under various conditions, which provides an important water-saving technology for greenhouse production.

Environmental and socio-economic performance of intensive farming systems with varying agricultural resource for maize production

The challenge of meeting the rising food demand and the need for achieving this through environment friendly and socio-economically acceptable strategies has posed an unprecedented pressure on the current intensive farming systems. Evidence for integrating the environmental burden and socio-economic profit is lacking. This study quantifies the yield performance, environmental burden (in terms of seven mid-point environmental impact categories, especially for the global warming potential (GWP) in terms of greenhouse gas emissions), and economic benefits among different intensive farming systems with varying agricultural resource input in maize (Zea mays) production. The results showed that seed yields increased with increasing resource inputs under intensive farming systems. Meanwhile, environmental burden in terms of GWP and integrated environmental impacts (IEI) based on per unit grain yield produced increased substantially with increasing resource inputs. The conventional planting accomplished the worst environmental performance (represented by the highest IEI), which was mainly attributed to higher agricultural resource input (such as fertilizer and diesel fuel consumption) per unit of grain yield produced, and thereby increased GWP, abiotic depletion-elements (Ade), ozone layer depletion (ODP), photochemical oxidation (PO), acidification potential (AP), and eutrophication potential (EP) by 22 %, 30 %, 36 %, 25 %, 32 % and 35 %, respectively. The relatively lower resource input under intensive farming coupled with water-saving technology could be highly recommended to local farmers; while extreme resource input planting patterns were not endorsed because of the yield penalty, low net revenue and high environmental burden. This study highlights the importance of an appropriate use of agricultural resources and innovative water-saving technology for mitigating environmental perils and ensuring global food supplies under intensive farming systems.

Analysis of the Influence of Agricultural Natural Disaster on Farmers’ Technology Adoption Decision

Xinjiang is the main cotton-producing area in China. However, its natural environment is special, and natural disasters frequently occur during the agricultural production process. Fortunately, the application of modern agricultural production technology provides a good tool for cotton farmers to reduce disaster losses. In order to analyze the impact of agricultural natural disasters on farmers’ adoption of agricultural production technology, based on the survey data of 216 cotton farmers in the main cotton production areas, this study uses a binary logistic model to analyze the impact of disaster types and stages on cotton farmers’ application of drip irrigation water-saving technology. The results show that hail, drought, and disease disasters have a significant impact on the application of drip irrigation water-saving technology, considering that the damage to equipment and technology’s control of disasters are the reasons behind; post-disaster remediation in the growth or maturity period also has a significant impact, which can reduce losses; and market price risk for cotton also has a significant impact.

Rebound Effects in Irrigated Agriculture in Uzbekistan: A Stakeholder-Based Assessment

There is wide consensus among scholars and practitioners that improved irrigation technologies increase farm productivity and improve resource use efficiency. However, there is also growing empirical evidence that efficiency improvements in irrigation water use may create rebound effects, i.e., they may trigger changes in farmers’ behavior that partly or fully offset the technical water savings expected under ceteris paribus conditions. In extreme cases, total water consumption may even increase. We studied the impacts of introducing water-saving irrigation technologies in Uzbekistan and used structured stakeholder interviews for an expert-based assessment of potential rebound effects. Our findings contribute to the understanding of impacts of technological and institutional responses to environmental and economic pressures in sustaining water resources. The study demonstrates that although the objective of increasing irrigation efficiency may be achieved, the actual water savings under Uzbek conditions are likely to be reduced due to rebound effects. Unless there are effective policy interventions, we expect rebound effects through an increase in water supply for crops that compensates for current shortages of irrigation water availability, an increase in irrigated area, a switch to more water-intensive crops, and overall economic growth. The findings of this paper provide a reference point for estimating the water-saving potential and for evaluating and adapting policies.

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.