Irrigation Water Use Research Articles

Perceptions of Farmers about Socio-economic Impacts of Drought: A Case Study of Mastung District, Balochistan

Drought is one of the most complicated natural disasters, affecting more people than any other natural disaster. There has been an increasing trend in the number of disasters reported globally over last few decades. Balochistan is among the areas which are arid and drought affected. This study was conducted in Balochistan region with the help of 200 samples of farmers from Mastung District. The farmers were interviewed helping study drought perception in the selected area. The objectives of this study were to find the impact of Mastung district drought how it has impacted the people in the region and what strategies people of Mastung district are taking to overcome this drought. Analysis shows the residents of Mastung District had a fair amount of understanding of climate changes. A vast majority of respondents (95.5%) reported experiencing drought occasionally. The vast majority of respondents 96%, reported that climate change is influencing drought intensity and frequency. The results about effect of drought on household income show that drought has impacted household income and caused significant challenges for the households. Almost all the respondents have reported decrease of livestock numbers due to drought. Results show that drought has a largely negative impact on crop yield, with most of respondents reported moderate declines in crop yield due to drought. A vast majority (98%) of respondents indicated that drought has moderately reduced employment opportunities in the area. All of the respondents confirmed that drought causes malnutrition among children. 57 % of farmers think that there are disputes over water for irrigation use in Mastung District. There are some drought mitigation strategies adopted by local people including storing grains, storing crop residue for livestock and the use of drought resistant crop were other coping strategies. The government and non-governmental organizations should assist the local population in strengthening the communities' resilience by increasing their capacity for adaptation in order to lessen the effects of drought.

Proposed water valuation scheme for a more sustainable agricultural water productivity

<p>Growing depletion of groundwater resources is a global threat and intensified under improper water valuation systems. Here, we proposed an irrigation water valuation framework based on the opportunity cost concept (IWVF), to better differentiate the value of surface water, renewable, and nonrenewable groundwater. In this study, a 10-years dataset was used in Marvdasht-Kharameh irrigation networks (MKINs) in southern Iran, where groundwater depletion overshoots the sustainable level with an annual average rate of 1.42 m y<sup>−1</sup>. Irrigation water use, net incomes and losses, and economic water productivities (EWP) were estimated under the common and newly developed valuation methods. The reflections of adopting IWVF on EWPs were assessed under current condition and the proposed WP improvement scenarios, including removing irrigation efficiency gaps, changing the cropping calendar, and application of different levels of deficit irrigation. Results showed that the value of irrigation water supply ($436.91 million) exceeds gross income through crop production ($139.01 million) under current condition, which results in a net loss of $297.9 million in the study area. Hence, economic WP loss will be −0.33 $ m<sup>−3</sup>, meaning that consuming a unit of blue water causes $0.33 income loss under current condition. Applying WP improvement scenarios can reduce value of irrigation water by 27%, and gross income by 5.3%. Accordingly, common WP can increase by 6.6% from 1.81 to 1.93 kg m<sup>−3</sup>. However, the negative sign of EWP loss under management scenarios (−0.22 $ m<sup>−3</sup>) indicates that crop production in the study area is not viable due to its considerable environmental damages. Hence, current irrigation system should be revisited when sustainable agriculture is considered. The proposed water valuation method can help decision makers to better assess the consequences of WP improvement strategies, if the true value of different water resources is ignored. </p>

Integrated Effects of Water and Nitrogen Coupling on Eggplant Productivity, Fruit Quality, and Resource Use Efficiency in a Cold and Arid Environment

In order to explore the water and fertilizer requirements of eggplants in the western oasis of the river, the experiment was conducted in Minle County of Gansu Province in 2022 and 2023 under three water stress gradients and three nitrogen application levels: (1) moderate water stress (W1, 50–60% in field water capacity [FC]), mild water stress (W2, 60–70% in FC), and full irrigation (W3, 70–80% in FC); (2) low nitrogen (N1, 215 kg·ha−1), medium nitrogen (N2, 270 kg·ha−1), and high nitrogen (N3, 325 kg·ha−1). Moderate and mild water stress were applied during eggplant flowering and fruiting while full irrigation was provided during the other growth stages; a control class (CK) was established with full irrigation throughout the whole plant growth without nitrogen application. This study investigated the effects of water-saving and nitrogen reduction on the yield, quality, and water-nitrogen use efficiency of eggplants in a cold and arid environment in the Hexi Oasis irrigation area of China. Using the EWM-TOPSIS model, we evaluated different water-nitrogen treatments and determined the optimal irrigation-nitrogen application model for eggplants in this region. The results showed that the W2N2 treatment had the highest yield, which was not significantly (p > 0.05) different from the W3N2 treatment while significantly (p < 0.05) 35.06% higher than CK in 2022 and 36.91% higher in 2023. In the W2N2 treatment, the transverse diameter of eggplants, as well as the contents of soluble protein, soluble sugar, soluble solids, and vitamin C, were all the highest. The W2N2 treatment had the maximum water use efficiency and irrigation water use efficiency, which were significantly higher than other water and nitrogen application treatments and CK by 14.79–42.51% in 2022 and 8.79–44.88% in 2023, and 15.86–45.55% in 2022 and 4.68–40.22% in 2023, respectively. By employing the EWM-TOPSIS model for comprehensive evaluation, the results indicated that mild water deficit (60–70% in FC) and moderate nitrogen application (270 kg·ha−1) at flowering and fruiting of eggplants was the optimal water and nitrogen application mode under mulched drip irrigation in the Hexi region of northwest China. The results will provide some theoretical basis for water-saving, productive, high-quality, and high-efficiency cultivation of eggplant in cold and arid environments.

Deficit Irrigation and an IoT-Based System for Improving Yield and Water Use Efficiency of Winter Wheat Grown Under Semi-Arid Conditions

In the context of water restriction, the adoption of innovative technology and water saving strategies is crucial to sustainable agriculture production. Thus, we sought to emphasize the contribution of precision irrigation based on Internet of Things (IoT) technology and smart sensors for optimizing irrigation water use. The effects of different drip irrigation regimes on total dry matter (TDM), grain yield (GY) and water use efficiency (WUE) of winter wheat grown on clay-loam soil under semi-arid conditions of Tunisia have been assessed for three consecutive growing seasons. The trial included fully irrigated (FI) treatment (100% of crop evapotranspiration (ETc)), two deficit irrigation treatments (DI1, DI2 corresponding to 75 and 60% of ETc, respectively) and rainfed treatment DI3, replicated three each. The results showed that TDM and GY increase with increasing irrigation amount. At harvest, the highest TDM and GY values were recorded under FI and DI1. Reducing irrigation amount by 40% (DI2) resulted in a significant grain yield reduction, quantified as 52.7, 45.7, 30.4%, respectively, for the three cropping seasons. Across all growing seasons and treatments, WUETDM values ranged between 4.11 and 6.32 Kg m−3. The highest values were achieved under rainfed treatment. However, no significant difference was observed between irrigated treatments, in particular, during 2022–2023 and 2023–2024. In terms of WUEGY, no significant difference was observed between the FI and DI1 treatments, while significant reductions were registered under DI2 and DI3. The adoption of deficit irrigation at 75% ETc based on smart tensiometers can be used as an effective strategy to optimize water use in winter wheat without compromising yield.

Identification of Salt Tolerance and Stress Response in US Department of Agriculture Tomato Germplasm at the Seedling Stage

Soil salinity is a significant abiotic factor that impedes sustainable crop production in key agricultural regions worldwide. Saline cultivation adversely affects soil quality, whereas the use of saline water for irrigation disrupts the physiological and biochemical processes of plants. Continuous irrigation with high salt concentrations leads to a gradual buildup of soil salinity, thus hindering optimal plant growth and development. Consequently, there is a growing emphasis on breeding salinity-tolerant cultivars of various crops. In this study, 71 tomato accessions sourced from 20 countries and provided by the US Department of Agriculture were evaluated under controlled greenhouse conditions and subjected to saline stress (200 mM NaCl). The experiment used a split-plot design, with the salt treatment serving as the main plot and the tomato accession as the subplot, which were arranged in a completely randomized design with three replications. Results identified nine accessions (PI 109837, PI 127820, PI 270256, PI 634828, PI 636205, PI 636255, PI 647143, PI 647528, and PI 647556) as salt-tolerant. Additionally, high broad-sense heritability was observed for the leaf injury score and leaf chlorophyll content. Furthermore, positive correlations were found among parameters related to the leaf injury score and leaf chlorophyll content (soil plant analysis development value). These findings offer valuable insights for tomato breeding programs, particularly those focused on enhancing salt tolerance of elite cultivars of this crucial crop.

Urban morphology and urban water demand: a case study in the land constrained Los Angeles region using urban growth modeling

Abstract The interactions between population growth, urban morphology, and water demand have important implications for water resources and supply in urban regions. Water use for irrigation comprises a significant fraction of urban water demand, and is potentially influenced by long-term changes in urban morphology. To investigate this, we used spatially explicit projections of urban land development intensity (fraction impervious area) generated from a 30 m resolution urban growth model for the Los Angeles (LA) region. Recent historical data on water use and high resolution landcover were used to establish relationships between green area, urban development intensity, and outdoor water demand. These relationships were then used to project outdoor and total water demand in 2100 using the urban growth model outputs. We considered two different population scenarios informed by the shared socioeconomic pathway (SSP) projections for the region (SSP3 and SSP5), and three scenarios of urban development intensification. Our analysis is resolved for over 80 water providers in the region, from the urban core to suburban fringe, and highlights diverse demand responses influenced by initial urban form and water demand attributes. Assumptions about outdoor water use factors based on recent water supply data were found to be nearly as influential on future outdoor demand as the urban growth scenario settings. Compared to previous studies, our work is unique in coherently linking high resolution SSP population scenarios, urban land cover evolution, and urban water demand projections, demonstrating the approach for the LA region—the largest population center in the western United States.

Impact of fish farm drainage water reuse for irrigation on barley yield and water productivity: Field study and simulation using the SALTMED model

AbstractCountries such as Egypt, which are situated in semi‐arid regions and have water constraints, primarily aim to repurpose unconventional water resources for irrigation. The aim of this research was to examine the feasibility and advantages of irrigating barley with fish farm drainage water (DWFF) rather than fresh irrigation water (IW). Four degrees of deficit irrigation [100% FI (full irrigation), 80% FI, 60% FI and 40% FI] were studied for the irrigation of barley via two types of water (DWFF and IW). The response of crops to a deficit irrigation approach involving the use of IW in the two seasons of 2020–2021 and 2021–2022 was demonstrated by the results. The yield of the barley produced with DWFF irrigation was greater than that produced with IW irrigation, ranging from 9% to 12% in 2020–2021 and from 9% to 13% in 2021–2022. This resulted from the higher concentration of dissolved biological nitrogen and other nutrients in DWFFs. There was a strong correlation between the observed and simulated crop yield values for both growing seasons, with R2 values of 0.963 and 0.960, respectively, for all the treatments. The SALTMED model was used to simulate the soil moisture content, water application efficiency, barley dry matter, yield and water productivity for all the treatments. The study concluded that DWFF is a useful irrigation substitute for IW. Higher yields were also attained with the use of less IW and chemical fertilisers because of the DWFF. In addition, there are other advantages, such as increasing farmer income and lowering discharge to the drainage network.

Improving future agricultural sustainability by optimizing crop distributions in China.

Improving agricultural sustainability is a global challenge, particularly for China's high-input and low-efficiency cropping systems with environmental tradeoffs. Although national strategies have been implemented to achieve Sustainable Development Goals in agriculture, the potential contributions of crop switching as a promising solution under varying future climate change are still under-explored. Here, we optimize cropping patterns spatially with the targets of enhancing agriculture production, reducing environmental burdens, and achieving sustainable fertilization across different climate scenarios. Compared with current cropping patterns, the optimal crop distributions under different climate scenarios consistently suggest allocating the planting areas of maize and rapeseed to the other crops (rice, wheat, soybean, peanut, and potato). Such crop switching can consequently increase crop production by 14.1%, with accompanying reductions in environmental impacts (8.2% for leached nitrogen and 24.0% for irrigation water use) across three representative Shared Socio-economic Pathways from 2020 to 2100. The sustainable fertilization rates vary from 148-173 kg N ha-1 in 2030 to 213-253 kg N ha-1 in 2070, significantly smaller than the current rate (305 kg N ha-1). These outcomes highlight large potential benefits of crop switching and fertilizer management for improving China's future agricultural sustainability.

Assessment of maize evapotranspiration, water requirements and productivity using weather data in Coimbatore’s semiarid climate

Accurately estimating crop water use is crucial for efficient water management in conservation agriculture, especially in Coimbatore's semiarid climate. This study assessed maize water use and productivity over three growing seasons (2023-2024) at AC&RI, Coimbatore. Irrigation applied each season varied between 500.8mm and 554.1 mm, averaging 535.8 mm, while total water supply ranged from 810.6 to 985.3 mm. Actual evapotranspiration (ETa) was estimated using locally developed crop coefficient curves (Lkc) and FAO crop coefficients. Water productivity for maize was calculated based on these estimates. Daily ETa for maize ranged from 0.9mm to 8.2 mm. Other than the different seasons, ETa varied from 342.6 to 372 mm, averaging 355.6 mm with the Lkc curve. By FAO Kc, ETa ranged from 400.8mm to 479.1 mm, with an average of 444.2 mm. The irrigation requirement ranged from 579.6mm to 672.7 mm, with an average of 629.5 mm using LKc. Using FAO Kc, the range was 637.8mm to 762.9 mm, with an average of 718 mm. Crop water use efficiency (CWUE) ranged from 0.8 and 0.9 kg/m³, with an average of 0.9 kg/m³. The evapotranspiration water use efficiency (ETWUE) ranged from 2.0 to 2.1 kg/m³, with an average of 2.1 kg/m³. The irrigation water use efficiency (IWUE) varied across seasons, averaging 1.4 kg/m³. Strong correlations were observed between CWUE, IWUE, and the amount of seasonal irrigation (R² = 0.98 and 0.99, respectively). CWUE and ETWUE strongly correlated with IWUE (R² = 0.98 and 0.75, respectively). These findings suggest that maize irrigation in Coimbatore's semiarid regions should be tailored to local conditions to enhance water productivity.

THE EFFECT OF DIFFERENT IRRIGATION LEVEL AND NITROGEN DOSES ON THE SILAGE YIELD AND QUALITY OF SORGHUM × SUDAN GRASS HYBRID (Sorghum bicolor L. × Sorghum sudanese)

This study aimed to determine the effects of different irrigation levels (I30, I60, and I100) and nitrogen doses (N0, N50, N100, and N150 kg ha-1) on the silage yield and quality of sorghum × Sudan grass hybrids (Sorghum bicolor L. × Sorghum sudanese). The experiment was conducted via a split-plot trial design with three replicates over two years, 2021 and 2022. Silage yield was evaluated over two years, and quality traits were evaluated over one year. Silage yield, irrigation water use efficiency (IWUE), water use efficiency (WUE), dry matter, pH, organic acids (lactic and acetic), relative feed value (RFV), crude protein, potassium (K), phosphorus (P), calcium (Ca), magnesium (Mg), total phenolic and total flavonoid content, DPPH free radical scavenging activity, and condensed tannin content were determined in the silage samples. The highest silage yield was observed in the I100×N1000 (64.3 t ha-1) and I100×N150 (61.8 t ha-1) treatments. The highest WUE was obtained from the I30×N150 interaction, whereas the highest IWUE value was obtained from the I30×N150 interaction. The lactic acid and crude protein contents of the silages ranged from 2.29-4.38% and from 6.51-9.70%, respectively. As a result, the silage yield decreased, whereas the silage quality was not affected by stress conditions. Accordingly, the I100xN1000 interaction, which results in the highest silage yield, is recommended.

Evaluation of indicators for improving the irrigation water use efficiency: Case of Guelma-Boucheggouf irrigated perimeter, Algeria

This study contributes to the evaluation of irrigation performance in the irrigated perimeter of Guelma-Boucheggouf, located in the Wila-ya of Guelma in northeastern Algeria. The aim was to evaluate the irrigation water-use efficiency (WUEi) as a performance indicator of the irrigated system at the perimeter with regard to the existing distribution scheme. It is calculated according to the equation adopted within the framework of the Mediterranean Strategy for Sustainable Development “Plan Bleu” (MSSD) in 2008. It is the prod-uct of the overall efficiency of the supply-distribution network (E1) and the plot irrigation efficiency (E2), and is subject to the irrigation methods used. The calculations yielded irrigation water-use effi-ciency (WUEi) of 46.1%. Examining the results for the 2019 to 2022 irrigation campaigns revealed significant losses between the pumped volumes and the ones released, which indicates a low ad-duction efficiency (Ea) of 54.22% and explains the inadequacy of the release system compared with the water saving strategies adopted by the national water plan in Algeria. The results also reveal the im-portance of the existing distribution system reflected by a distribu-tion efficiency (Ed) of 82.08%, which reduced the overall efficiency of the network (E1) calculated from the two efficiencies to 56.58%, indicating an average loss of 9.8 Hm3 between the released volumes and those distributed. The plot efficiency (E2), calculated at 82%, was acceptable due to its dependence on the irrigation methods used; however further improvement is needed.

Analisis Permeabilitas Tanah Berpasir Dan Tanah Lempung Dalam Hubunganya Dengan Manajemen Irigasi

This research examines the permeability characteristics of sandy and clay soils and their implications for irrigation management in agricultural systems. Soil permeability is a key factor in determining water use efficiency and optimal irrigation strategies. The research methodology includes laboratory analysis of sandy and clay soil samples from various agricultural locations, measuring physical soil characteristics, infiltration rates, water storage capacity, and hydraulic conductivity. The results show significant differences between the two soil types, where sandy soil has high permeability ranging from 10^-3 to 10^-2 cm/second, low water storage capacity, and rapid infiltration rates, thus requiring more frequent irrigation with smaller volumes. In contrast, clay soil has low permeability ranging from 10^-7 to 10^-6 cm/second, high water storage capacity, and slow infiltration rates, requiring less frequent irrigation with larger volumes. Based on these results, specific irrigation management recommendations were developed that include irrigation schedule adjustments, water volume regulation, selection of appropriate irrigation methods, and water conservation techniques. This research provides important contributions to optimizing irrigation water use based on soil permeability characteristics, which can improve water use efficiency and agricultural productivity.

Optimizing Irrigation Strategies to Improve Yield and Water Use Efficiency of Drip-Irrigated Maize in Southern Xinjiang

The contradiction between increased irrigation demand and water scarcity in arid regions has become more acute for crops as a result of global climate change. This highlights the urgent need to improve crop water use efficiency. In this study, four irrigation volumes were established for drip-irrigated maize under plastic mulch: 2145 m3 ha−1 (W1), 2685 m3 ha−1 (W2), 3360 m3 ha−1 (W3), and 4200 m3 ha−1 (W4). The effects of these volumes on soil moisture, maize growth, water consumption, crop coefficients, and yield were analyzed. The results showed that increasing the irrigation volume led to a 2.86% to 8.71% increase in soil moisture content, a 24.56% to 47.41% increase in water consumption, and a 3.43% to 35% increase in the crop coefficient. Maize plant height increased by 16.34% to 42.38%, ear height by 16.85% to 51.01%, ear length by 2.43% to 28.13%, and yield by 16.96% to 39.24%. Additionally, soil temperature was reduced by 1.67% to 5.67%, and the maize bald tip length decreased by 6.62% to 48%. The irrigation water use efficiency improved by 6.57% to 28.89%. A comprehensive evaluation using the TOPSIS method demonstrated that 3360 m3 ha−1 of irrigation water was an effective irrigation strategy for increasing maize yield under drip irrigation with plastic mulch in the southern border area. Compared to 4200 m3 ha−1, this strategy saved 840 m3 ha−1 of irrigation water, increased the irrigation water use efficiency by 23.96%, and resulted in only a 0.84% decrease in yield. The findings of this study provide a theoretical foundation for optimizing production benefits in the context of limited water resources.

Optimization of Maize Irrigation Strategies in the Middle Reaches Irrigation Area of the Heihe River Using a Differential Evolution Algorithm

Optimizing maize irrigation strategies is essential for improving water use efficiency and crop yields in arid regions. However, limited quantitative research exists on these optimizations. This study focuses on the Heihe River Basin in China, aiming to (1) optimize maize irrigation strategies using a differential evolution (DE) algorithm integrated with the AquaCrop model and remote sensing data; (2) compare the DE algorithm’s performance with the traditional Nelder–Mead (fmin) algorithm regarding yield improvement and irrigation water use; and (3) assess the benefits of different irrigation strategies under limited water availability. Covering 22 irrigation management zones in Zhangye City, Gansu Province, the study utilized soil, weather, and crop data from Google Earth Engine to drive the AquaCrop model. Results indicate that the DE algorithm achieved higher simulated maize yields, increasing by 0.5 to 1 t/ha on average compared to the fmin algorithm, albeit with a 30% rise in irrigation water usage. The integration of both the DE and fmin algorithms with the AquaCrop model facilitates the development of tailored irrigation strategies, providing a scientific foundation for sustainable agricultural water management. These findings can guide efficient irrigation management plans in the region and similar arid systems.

Comparison of Oxytetracycline and Sulfamethazine Effects Over Root Elongation in Selected Wild and Crop Plants Commonly Present in the Mediterranean Cropland and Pasture Scenarios.

Fertilization with animal manure and sewage sludge, and the use of sewage water for irrigation, can lead to high antimicrobial concentrations in agricultural soils. Once in soil, antimicrobials can exert direct and indirect toxic effects on plants by misbalancing plant-microbe symbiotic relationships. We performed germination tests to determine the optimum germination conditions of 24 plant species (10 crop and 14 wild species). Subsequently, we analyzed the differences in oxytetracycline and sulfamethazine phytotoxicity in 19 plant species for which optimum germination conditions could be established. The root elongation of the majority of wild species was inhibited in the presence of oxytetracycline and sulfamethazine, whereas crops were mainly affected by oxytetracycline. There were no differences in sensitivity to oxytetracycline between crop and wild plant species, whereas wild plants were significantly more susceptible to sulfamethazine than crop species. Thus, to cover both productivity and biodiversity protection goals, we recommend pharmaceuticals' predicted no-effect concentration (PNEC) values based on crop and wild plant species phytotoxicity data.

ANALISIS PENGGUNAAN AIR IRIGASI TETES BERTINGKAT EMPAT PADA USAHATANI TANAMAN CABAI DI PERMUKIMAN PERKOTAAN.

The use of a multilevel drip irrigation system for agriculture in urban residential areas needs to be done so that food availability can always be available, which must be supported by the use of appropriate planting media. This study aims to determine the amount of use by chili plants in polybag media irrigated by a four-level drip irrigation system with a mixture of soil and compost and livestock waste. Tests were carried out on the provision of drip irrigation, infiltration capacity and soil moisture produced at certain durations for each phase of plant growth (chili). The composition of the soil planting media to the compost is 60%: 40%, 70%: 30%, 80%: 20%. The test was carried out on a PVC drip irrigation network with emitters in a 2m x 4m x 2m room with 96 polybags, water sources from a 150 liter tank with a height of 2.5 m. Data analysis was carried out on irrigation discharge data, uniformity, irrigation depth and soil moisture against irrigation water use. The test results show that the amount of irrigation water used for chili plants in the early growth phase is around 40 liters, the use of water in the vegetative plant growth phase is around 60 liters to 120 liters, in the generative phase it is 130 liters to 300 liters and in the fruiting phase until the harvest phase, around 325 liters - 500 liters of water are used. The use of irrigation water is the cumulative amount from early irrigation to post-harvest. The highest water use needs to be given to plants on the first and fourth floors in the dry season and in the rainy season the lowest irrigation water use is for plants on the first and fourth floors.

Reuse of Treated Sanitary Sewage to Restore Degraded Soil

Objective: The objective of this study is to evaluate the effects of treated domestic wastewater reuse at different dosages on a degraded soil in the western region of Bahia, Brazil, focusing on the recovery of its chemical and biological properties. Method: The methodology of this study involves tests for characterizing the treated wastewater and the soil after the treatments. The experimental design was completely randomized with 4 treatments and 4 replications, totaling 16 experimental units. Both the soil and the treated wastewater were analyzed based on pH, NTK, P, K, and TOC. The soil was also analyzed for basal respiration. Results and Discussion: The application of treated wastewater increased macronutrients, raised the concentration of available phosphorus and potassium content, led to an increase in total organic carbon, and enhanced soil basal respiration. Research Implications: This research has practical implications by presenting the characteristics of a soil degraded by human activities and proposing a recovery technique. Furthermore, the reuse of treated wastewater contributes to improved water resource management by avoiding the discharge of wastewater into water bodies and reducing the use of water for irrigation. Originality/Value: This study contributes by addressing the effects of treated wastewater reuse on degraded soil, promoting its recovery through the improvement of its chemical and biological characteristics. This is a topic that has been little studied, especially in the type of degraded soil of the Brazilian Cerrado, where the expansion of agriculture exerts significant pressure on the environment.

Laser land leveling technology for paddy production in Vietnam: impact on efficient irrigation and water conservation.

This research investigates the empirical effects of the laser land leveling (LLL) adoption on irrigation water and water efficiency in paddy production in the Mekong Delta region (MDR), using the randomized controlled trial (RCT) approach incorporated into input demand function models. The descriptive analysis highlights the potential for water reuse through farmers' drainage practices. However, the dependence on experiential methods for applying technology in paddy production poses challenges that could compromise long-term sustainability. The regression results indicate that the LLL treatment leads to savings of 1975 m3ha-1 and 1299.35 m3ha-1 in irrigation water and net water use in paddy production, respectively, compared to the control. These savings account for 20.52% of total irrigation water use and 28.64% of net water use. The projected savings on average are 375.51 and 247.05 million m3, respectively, for irrigation water and net water use with 5% implementation of the technology in the MDR. The research highlights the environmental benefits of the LLL technology and underscores the need for its promotion to achieve water conservation in paddy production, offering policymakers insights to enhance sustainable agriculture amid climate change and water scarcity. The study addresses significant gaps in the existing literature by providing an in-depth analysis of LLL technology's impact on irrigation water and efficiency by extending the drainage performance within the paddy mono-cropping context and employing RCT methodology combined with input demand function models to comprehensively evaluate its impact on irrigation water usage.

Green and efficient fine control of regional irrigation water use coupled with crop growth-carbon emission processes

The effective, environmentally friendly, and optimally deployed management of regional agricultural water resources is crucial to ensuring food security and the sustainable use of water resources in the face of challenging agricultural issues, such as increasing greenhouse gas (GHG) emissions, water scarcity, and rapid population and economic growth. In this study, a multiobjective model for the optimal distribution of regional agricultural water resources was built, using the GIS-DSSAT and GIS-DNDC models, to simulate the regional spatial raster crop growth process and carbon emission process. The model allowed for the creation of synergies in both crop production and emission reduction. The model was solved using a fuzzy planning algorithm, and applied to the main Sanjiang Plain grain production area in Heilongjiang Province, yielding the best water allocation scheme and a set of planting structure adjustment schemes for the main grain crops of rice, maize, and soybeans in 1074 Sanjiang Plain response units. In contrast to the current method, which relies heavily on soil and water resources, the model developed in this paper reduced greenhouse gas (GHG) emissions by 10 %, energy consumption by 14.4 %, and regional irrigation water use by 34.48 %. It achieved the dual goal of reducing GHG emissions and conserving water, while increasing the synergy between increased regional food production and decreased emissions by 21 % compared to the status quo. Climate change will pose series of challenges to agricultural production, particularly the arable land and water resource usage. By optimizing cropping structures and irrigation systems, climate-adaptive management can not only reduce the area of arable land and water consumption, but also decrease carbon emissions; for the SSP2–4.5 and SSP3–7.0 scenarios, this trend resulted in increases in economic benefits of 2.4 % and 3.3 %, respectively, and decreases in carbon emission scenarios of 14.6 % and 20.7 %, respectively. The yields and GHG emissions of the response units were sensitive to these changes. This study offers decision-making support for the intense, effective, and low-carbon management of water resources.

Improving Irrigation Water Use Efficiency and Maximizing Vegetable Yields with Drip Irrigation and Poly-Mulching: A Climate-Smart Approach

Water management is a significant aspect of sustainable vegetable farming, especially in water-scarce regions. This, in addition to weed infestations, limits vegetable yields, which negatively affect food security in developing regions, particularly East Africa, where livelihoods chiefly depend on rain-fed agriculture. Vegetable farming, especially tomato cultivation, requires more water. By promoting mulching, a soil water conservation tool, we can control surface evaporation (E), which, together with irrigation, enhances effective water use and vegetable yields. The experiments for this study were conducted at the Tokyo University of Agriculture, Japan, to evaluate the influences of different irrigation conditions and poly-mulching on weed control, tomato yields, and water use efficiency. The study was conducted from May to September 2018 on a 30 m2 plot in an open-ended greenhouse using drip irrigation for tomato cultivation. Three predetermined irrigation conditions of 4, 3, and 2 mm/day were applied on black poly-mulched and bare ridges. Data on soil conditions—soil temperature, as well as meteorological variables, including solar radiation and temperature—were measured using thermocouple sensors and micro-hobo weather stations, respectively, during the tomato cultivation, while yield components—growth, yield, water productivity, and sugar content—were determined after harvest. The results of a two-way ANOVA show that irrigation conditions with poly-mulching reduced the weed biomass significantly, and improved yields and water use efficiency compared to the irrigation conditions on bare ridges. The application of 4, 3, and 2 mm/day irrigation with poly-mulching significantly reduced the weed biomass by 5% compared to the same irrigation conditions on bare ridges. Similarly, 4 and 3 mm/day irrigation conditions with poly-mulching significantly increased the tomato yield by 5% compared to 2 mm/day on bare ridges. The bigger roots were concentrated and widely distributed at the shallow soil depth (0–20 cm) of the ridges with high irrigation amounts, while the small and thin roots were in deeper soil layers (30–45 cm). This study provides scientific knowledge on the application of predetermined irrigation conditions that can be (i) integrated into irrigation scheduling and (ii) adopted for regions facing water scarcity and limited or no in situ meteorological data, to improve water use efficiency for vegetable cultivation.