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Egypt is grappling with water shortage, with agriculture using about 80% of its water consumption. Climate change is only going to further complicate water availability and water consumption. This study investigates the potential impacts of climate change on irrigation demands in the Western Nile Delta of Egypt, focusing on both coastal region, Mahmodia, (Ma) and interior region, Nubaria, (Nu). An ensemble of 40 Global Circulation Models (GCM) was utilized to project climate conditions under two representative concentration pathways, RCP4.5 and RCP8.5, based on the Intergovernmental Panel on Climate Change (IPCC) and the Fifth Assessment Report. The CROPWAT model was used to calculate the reference evapotranspiration (ET0) and the crop water requirements (CWR) for key crops in the Western Nile Delta. This included summer crops (sugar beet, cotton, summer maize, summer tomato, watermelon and sweet melon), winter crops (wheat, alfalfa, winter potato, winter squash and broad bean), and permanent crops (orange, apple, grape, and olives). The assessments considered both historical and projected climate data extending until 2100. According to RCP8.5 scenario, the findings indicate a projected rise in CWR rates in Nubaria, with an increase of 1.03%, 1.15%, and 0.94% per decade until the end of the century for summer, winter, and permanent crops, respectively. Similarly, Mahmodia is expected to experience a rise in CWR rates by 1.1%, 1.16%, and 1.08% per decade for the same crop categories until 2100. These projections underscore the urgent necessity to integrate climate change considerations into water resource management strategies to enhance the efficiency of these strategies.

Conventional flood irrigation is the common irrigation system practiced in many developing countries. Under this regime, a large quantity of water is used to irrigate a variety of crops, such as banana, which consumes about 1,200–2,200 mm of water per year. Using the example of Yemen, the main objective of this study was to explore how to save as much of groundwater as possible and select the most suitable irrigation depth that does not affect the quantity and quality of banana production in the Al Mahwit governorate. Two models were used in this investigation. The BROOK90 (B90) hydrological model was employed to examine the banana field under existing water depth (1,500 mm year−1) and under two irrigation-reduction scenarios (1,000 and 500 mm year−1), and CROPWAT was applied to validate the findings of the B90 model, taking advantage of the monthly climate data in the CROPWAT package. Climate data were collected and field measurements of water consumption rates, plant characteristics, and soil properties were taken. The results show that the current irrigation depth with a quantity of 1,500 mm year−1 is more than the banana water requirements and most of the irrigation water is lost to seepage. The irrigation scenario with 500 mm year−1 appeared to be less than the banana water requirement, and water stress was observed. The scenario of 1,000 mm year−1 was found to be appropriate. Actual evapotranspiration (ET), soil water content (SWC), and seepage (SEE) had standard rates, and there was no stress in the soil. Most importantly, following the suggested irrigation schedule of 1,000 mm year−1 will save as much as 500 mm year−1 of groundwater compared with current water use. Furthermore, evaluation of effective rainfall and the tested irrigation depths to meet the amount of water required by banana indicated a strong correlation between CROPWAT and the B90 model with an average percentage bias of 13.2. Overall, both models yielded identical results, confirming the finding of an optimal irrigation depth. Practical Applications: Agriculture consumes a great amount of freshwater resources, making efficient water management imperative. This research from Yemen presents a universally applicable solution for optimizing irrigation practices and emphasizes the importance of calculating the actual water input for high-demand crops such as banana. The BROOK90 and CROPWAT models can be used in any region of the world to address water scarcity challenges. Furthermore, the strong agreement between the CROPWAT and B90 models in the validation of the proposed optimal irrigation depth makes the study findings more sensible and applicable, with no effect on banana productivity. The research introduces an innovative strategy to improve water-use efficiency in agriculture. In arid and semiarid regions, the irrigation depth of 1,000 mm for banana cultivation is proven to be sufficient, and would result in a considerable saving of groundwater for other uses. From a farmer's perspective, saving water will result in a great reduction of the fuel required for operating water wells and also will save time and labor. Moreover, conflicts among water users over limited water resources are expected to diminish. Therefore, supplying banana with the actual irrigation input, based on intensive field research, is essential, and promises a significant conservation of groundwater resources on a larger scale. [ABSTRACT FROM AUTHOR]

This study aims to estimate the consumptive water use (CWU) for watermelon production in Auchi, Edo State, Nigeria. The research was conducted over a period of eight months (March–October) and used data collected from the watermelon field at the Demonstration and Research Farm of Auchi Polytechnic, Auchi. The result of the experiment revealed the estimation of CWU and watermelon water requirements (CWR) of 175.9 mm and 195 mm for the 62-day (August to October) vegetation stage of watermelon, with a CROPWAT projected harvest on November 20, 2022. The finding also revealed that the mean annual consumptive water use for watermelon production was 520.7 mm. The mean seasonal water use for watermelon production was higher in the dry season (March to June, 488.7mm) than in the wet season (July to October, 390.6mm). However, based on this harvest date, the model predicted irrigation requirements of 23.1 mm and 59.4 mm in October and November. Additionally, this study offers proof that management strategies for water use efficiency and irrigation scheduling can dramatically lower water losses and boost efficiency. The findings of this study can be applied to the Auchi region’s water management decision-making procedures as well as to help watermelon farmers reduce their water consumption levels while maintaining output.

The research was conducted to assess the climate change impact on crop water requirements (CWRs) in the Woybo catchment of southern Ethiopia. The impact of climate change was assessed through climate models under RCP4.5 and RCP8.5 emission scenarios for the 2050s compared to 1971–2005. During the 2050s, the annual mean minimum temperature increased by 1.9–2.3 °C, while the maximum temperature over the catchment increased by 1.4–2.0 °C. The projected rainfall is expected to increase in autumn, summer, and annually by 3.7–16.8 and 8.7–12.2% in the 2050s under RCP4.5 and 8.5, respectively. But it is likely to decrease in winter and spring by 1.5–10.2% and 8.7–2.8%, respectively. The average annual potential evapotranspiration will rise by 0.1–6.8%. Under both RCPs, CWRs may increase from 6.2 to 17.2% during the growing season, while irrigation water requirements (IWRs) may rise from 4.6 to 16.4%. Future period projection results show that potential evapotranspiration and IWRs will increase for maize crops compared to the baseline period. The study will help water managers, users, and agricultural developers in preparing new water-saving strategies and achieving agricultural sustainability. HIGHLIGHTS Due to continuous change in climatic conditions, farmers are abruptly facing a huge loss due to erratic rainfall, increase in temperature, insufficient irrigated water, and many other causes.; An attempt has been made in this research to study the impact of climate change on maize production and, with different scenarios, the effects have been calculated and assessed.; The RCPs are well augmented.;

The irrigation systems require modernization and management by evaluating water system prerequisites precisely. A study was carried out at Srinagar during kharif 2022 to determine the crop water demands, irrigation scheduling and simulation of moisture movement under different irrigation regimes on tomato crop in open field conditions using CROPWAT and HYDRUS-1D models. The results revealed that the average crop water requirement at 100% ETC per plant per day was 0.24 l plant-1 day-1 during the initial stage, 0.37 l plant-1 day-1 during development stage, 0.85 l plant-1 day-1 during mid-stage and 0.74 l plant-1 day-1 during the end stage. Soil water content was simulated by HYDRUS-1D model in 0 to 30 cm of soil profile. Higher values (0.86 to 0.95) of coefficient of determination (R² ) indicated that observed and simulated values of moisture content are highly correlated and the model predicts that lower values of mean absolute error (MAE) and root mean square error (RMSE) indicates that the HYDRUS-1D model is more accurate at simulating the movement of moisture under different irrigation regimes. [ABSTRACT FROM AUTHOR]

IntroductionIrrigation planning is one of the management strategies, which is based on determining the exact water requirement. The lysimetric method is the most accurate method of determining the water requirement of the plant, but due to the high cost and the need for high technical knowledge, it cannot be used anywhere. The basis for determining the water requirement in the Ardabil Plain is the use of NETWAT software output information, which is known as the National Water Document of Iran. This software calculates the water requirement using the Penman-Monteith FAO model. The output of this software due to the need to update climate information, not introducing the exact range of plains, ignoring sub-climates in some plains and catchments (including Ardabil Plain), and not considering some important crops in the plain (lack of potato water requirement in Ardabil Plain) and the creation of new databases in recent years, should be reconsidered. Material and MethodsThis study in Ardabil Plain and water requirement of the dominant crop pattern including wheat, barley, potato, alfalfa, and bean crops was calculated by the Penman-Monteith method and CROPWAT software. To calculate the net irrigation requirement, first, the evapotranspiration potential of the plain was obtained using climatic information from three stations Ardabil, Abi Biglou, and Namin. Then, the effective rainfall of the plain was extracted by the information from Ardabil, Abybeigloo, Namin, Koozeh Topraghi, Gilande, and Samian rain gauge stations. Required information on plain soil was prepared using 22 points in the plain. In the last step of the information preparation phase, the characteristics of the cropping pattern plants were defined using field measurements, local experiments, and FAO publication No. 56. The cropping pattern (91.4% of the cultivated area of Ardabil Plain) included wheat, barley, potatoes, alfalfa, and beans, which according to the five-year statistics ending in 2021, the cultivated area of these crops was 18,300 (32.6%), 10300 (19.4%), 15700 (28%), 5200 (9.2%) and 1200 (2.2%) hectares. After preparing the case information, the water requirement was calculated for each of the wheat, barley, potato, alfalfa and bean products in each of the soil sampling points in 10-day periods during the growing season. Based on the point information obtained, a zoning map of net irrigation needs in the Ardabil Plain was prepared. Results and DiscussionBased on the obtained point information, a zoning map of net irrigation needs in the Ardabil Plain was prepared. The results showed that the zoning of the net need for irrigation divides the Ardabil Plain into three separate parts in this regard. The northern part and the southern part are divided into high consumption, the eastern and southeastern parts are low consumption, and the western part and parts of the center are divided into medium consumption. In addition, according to the zoning results, the average, minimum, and maximum net irrigation needs of the crops were calculated. For the wheat crop, the average, minimum, and maximum net irrigation requirements were 164, 314, and 259 mm, respectively. For the barley crop, the average, minimum, and maximum net irrigation requirements were 110, 255, and 205 mm, respectively. For the potato crop, the average, minimum, and maximum net irrigation requirements were calculated as 325, 613, and 484 mm, respectively. In addition, for alfalfa and bean crops, the mean, minimum, and maximum net irrigation requirements were estimated at 425, 872, and 670 mm and 337, 637, and 497 mm, respectively. ConclusionThe results showed that if the average of the whole plain is used for wheat, barley, potato, alfalfa, and bean crops, instead of point or regional information, about 18, 20, 21, 23, and 22% deficit irrigation, respectively, and in Low consumption sector accounts for about 58, 86, 49, 58, and 48% of excess irrigation. Also, the results showed that using the output numbers of NETWAT software will cause wrong water management in Ardabil Plain. Therefore, using the results of the National Water Document (NETWAT) will lead to incorrect water management due to the problems mentioned. That is if the results of the national document are used as the basis for determining the water requirement in the Ardabil Plain, compared to the minimum and maximum numbers obtained from this research, about 32 and 38 MCM will occur in the exceeding irrigated and deficit irrigated plains, respectively (without considering the impact potato crop due to not calculating its water requirement in the national water document for Ardabil Plain). Considering climate change and also the development of different databases, it is suggested to use up-to-date information for water requirement calculations. Also, considering that the Ardabil Plain is divided into three separate parts in terms of the net need for irrigation, therefore it is recommended that instead of using one number as the consumption in the whole plain, from point or regional information obtained from this research for wheat, barley, Use potatoes, alfalfa and beans.

This study was done to examine agricultural water and irrigation schedules for key crops grown in Kohima area of Nagaland, India, which has a humid subtropical climate. Climatic data over 16 years (2006–2021) were used to estimate crop water requirements using CROPWAT 8.0 model. Rice, maize, soybean, potato, cabbage, dry bean, ginger, and naga chili are the most common crops. ET0 was calculated using the FAO Penman–Monteith method and ranged from 1.41 to 3.65 mm/day. The USDA SCS approach calculated effective rainfall. The average annual ETC for rice, maize, ginger, soybean, bean (dry), potato, cabbage, and naga chili were 537.1, 305.7, 342.7, 292.2, 288.1, 364.3, 190.6, and 141 mm, respectively. Rice, maize, ginger, soybean, bean (dry), potato, cabbage, and naga chili require an average of 251.7, 54.9, 26, 73.1, 21.3, 21.9, 121.9, and 14.5 mm of irrigation each year, respectively. The crop irrigation schedules were created with 70% efficiency. The study emphasizes that irrigation must be adjusted to each crop's individual needs, whether through strategic scheduling or modifying net and gross irrigation volumes, to enhance water management and maximize crop production in the region. HIGHLIGHTS This study emphasizes water requirement and irrigation planning for the hilly district of Kohima.; This study highlights individual crop demand through strategic scheduling to maximize production.; Fulfilling Sustainable Development Goal 2 achieves food security and promotes sustainable agriculture in hilly regions of India.; Efficient irrigation management maximizes yield and minimizes water stress.; This study's findings will help in water resources planning in the Kohima region.;

The sustainable management of water scarcity is a globally crucial issue. Germany has established efficient water management systems, but the agricultural sector still struggles with water scarcity as the demand surpasses the available water supply. In this work, the primary aim was to establish a framework for making water accessible for irrigation and additional use in households through the effective utilization of recycled water from wastewater treatment facilities. The research inquiries were focused on evaluating the changes in the CROPWAT agricultural irrigation model, determining the spatial distribution of zonal severity, estimating the capacity of urban roof catchments, and evaluating the economic value addition of retreated water from the existing wastewater treatment plant supply. According to the findings, the annual amount of water required for agriculture in the designated study location is approximately 2.9 million m3. Although there is no initial need for irrigation water, the demand for irrigation water increases during the development, active growth, and mature stages of maize, winter wheat, and wine grapes, reaching around 189 mm, 223 mm, and 63 mm, respectively. According to our observations, the annual water supply in Weinstadt is around 4 million m3. On the other hand, the compensated volume of water to the current water supply calculated from the urban roof rainfall is estimated to be 0.8 million m3, which is considered valuable from an economic standpoint. This economically efficient volume of water would reduce the current treated water supply, which indicates an opportunity for enhanced agricultural irrigation. [ABSTRACT FROM AUTHOR]

This article discusses a study that compared traditional furrow irrigation with the CROPWAT irrigation scheduling method for tomato crops. The study found that the CROPWAT method saved 35.69% of water and resulted in a 36.8% higher yield for the tomato crop. The study concludes that the CROPWAT model is effective for strategic planning in irrigation management and water-saving technology. The document provides specific details on the volume of water applied and the crop yield under each method, highlighting the benefits of adopting the CROPWAT method for increased crop yield and water savings. [Extracted from the article]

This study aims to estimate the consumptive water use (CWU) for watermelon production in Auchi, Edo State, Nigeria. The research was conducted over a period of eight months (March-October) and used data collected from the watermelon field at the Demonstration and Research Farm of Auchi Polytechnic, Auchi. The result of the experiment revealed the estimation of CWU and watermelon water requirements (CWR) of 175.9 mm and 195 mm for the 62-day (August to October) vegetation stage of watermelon, with a CROPWAT projected harvest on November 20, 2022. The finding also revealed that the mean annual consumptive water use for watermelon production was 520.7 mm. The mean seasonal water use for watermelon production was higher in the dry season (March to June, 488.7mm) than in the wet season (July to October, 390.6mm). However, based on this harvest date, the model predicted irrigation requirements of 23.1 mm and 59.4 mm in October and November. Additionally, this study offers proof that management strategies for water use efficiency and irrigation scheduling can dramatically lower water losses and boost efficiency. The findings of this study can be applied to the Auchi region's water management decision-making procedures as well as to help watermelon farmers reduce their water consumption levels while maintaining output. [ABSTRACT FROM AUTHOR]

Introduction Irrigation planning is one of the management strategies, which is based on determining the exact water requirement. The lysimetric method is the most accurate method of determining the water requirement of the plant, but due to the high cost and the need for high technical knowledge, it cannot be used anywhere. The basis for determining the water requirement in the Ardabil Plain is the use of NETWAT software output information, which is known as the National Water Document of Iran. This software calculates the water requirement using the Penman-Monteith FAO model. The output of this software due to the need to update climate information, not introducing the exact range of plains, ignoring sub-climates in some plains and catchments (including Ardabil Plain), and not considering some important crops in the plain (lack of potato water requirement in Ardabil Plain) and the creation of new databases in recent years, should be reconsidered. Material and Methods This study in Ardabil Plain and water requirement of the dominant crop pattern including wheat, barley, potato, alfalfa, and bean crops was calculated by the Penman-Monteith method and CROPWAT software. To calculate the net irrigation requirement, first, the evapotranspiration potential of the plain was obtained using climatic information from three stations Ardabil, Abi Biglou, and Namin. Then, the effective rainfall of the plain was extracted by the information from Ardabil, Abybeigloo, Namin, Koozeh Topraghi, Gilande, and Samian rain gauge stations. Required information on plain soil was prepared using 22 points in the plain. In the last step of the information preparation phase, the characteristics of the cropping pattern plants were defined using field measurements, local experiments, and FAO publication No. 56. The cropping pattern (91.4% of the cultivated area of Ardabil Plain) included wheat, barley, potatoes, alfalfa, and beans, which according to the five-year statistics ending in 2021, the cultivated area of these crops was 18,300 (32.6%), 10300 (19.4%), 15700 (28%), 5200 (9.2%) and 1200 (2.2%) hectares. After preparing the case information, the water requirement was calculated for each of the wheat, barley, potato, alfalfa and bean products in each of the soil sampling points in 10-day periods during the growing season. Based on the point information obtained, a zoning map of net irrigation needs in the Ardabil Plain was prepared. Results and Discussion Based on the obtained point information, a zoning map of net irrigation needs in the Ardabil Plain was prepared. The results showed that the zoning of the net need for irrigation divides the Ardabil Plain into three separate parts in this regard. The northern part and the southern part are divided into high consumption, the eastern and southeastern parts are low consumption, and the western part and parts of the center are divided into medium consumption. In addition, according to the zoning results, the average, minimum, and maximum net irrigation needs of the crops were calculated. For the wheat crop, the average, minimum, and maximum net irrigation requirements were 164, 314, and 259 mm, respectively. For the barley crop, the average, minimum, and maximum net irrigation requirements were 110, 255, and 205 mm, respectively. For the potato crop, the average, minimum, and maximum net irrigation requirements were calculated as 325, 613, and 484 mm, respectively. In addition, for alfalfa and bean crops, the mean, minimum, and maximum net irrigation requirements were estimated at 425, 872, and 670 mm and 337, 637, and 497 mm, respectively. Conclusion The results showed that if the average of the whole plain is used for wheat, barley, potato, alfalfa, and bean crops, instead of point or regional information, about 18, 20, 21, 23, and 22% deficit irrigation, respectively, and in Low consumption sector accounts for about 58, 86, 49, 58, and 48% of excess irrigation. Also, the results showed that using the output numbers of NETWAT software will cause wrong water management in Ardabil Plain. Therefore, using the results of the National Water Document (NETWAT) will lead to incorrect water management due to the problems mentioned. That is if the results of the national document are used as the basis for determining the water requirement in the Ardabil Plain, compared to the minimum and maximum numbers obtained from this research, about 32 and 38 MCM will occur in the exceeding irrigated and deficit irrigated plains, respectively (without considering the impact potato crop due to not calculating its water requirement in the national water document for Ardabil Plain). Considering climate change and also the development of different databases, it is suggested to use up-to-date information for water requirement calculations. Also, considering that the Ardabil Plain is divided into three separate parts in terms of the net need for irrigation, therefore it is recommended that instead of using one number as the consumption in the whole plain, from point or regional information obtained from this research for wheat, barley, Use potatoes, alfalfa and beans. [ABSTRACT FROM AUTHOR]

Global climate change affects agriculture by influencing crop phenology and water requirements. This study aims to understand the effects of climate change on rice phenology and assess the case of the drought-prone Rajshahi district of Bangladesh by exemplary estimation of a climate model-based future crop water requirement. Studies indicate a high possibility of future temperature and humidity increases by the 2050s and 2080s. Increased temperature potentially reduces the length of individual growth stages and total growth stage and, ultimately, the crop water requirement. However, the increased humidity percentage and high temperature may severely affect grain development by causing spikelet sterility. There is a possibility of a considerable reduction in the rain-fed yield of winter rice in the case study area. [ABSTRACT FROM AUTHOR]

The irrigation systems require modernization and management by evaluating water system prerequisites precisely. A study was carried out at Srinagar during kharif 2022 to determine the crop water demands, irrigation scheduling and simulation of moisture movement under different irrigation regimes on tomato crop in open field conditions using CROPWAT and HYDRUS-1D models. The results revealed that the average crop water requirement at 100% ETC per plant per day was 0.24 l plant-1 day-1 during the initial stage, 0.37 l plant-1 day-1 during development stage, 0.85 l plant-1 day-1 during mid-stage and 0.74 l plant-1 day-1 during the end stage. Soil water content was simulated by HYDRUS-1D model in 0 to 30 cm of soil profile. Higher values (0.86 to 0.95) of coefficient of determination (R2) indicated that observed and simulated values of moisture content are highly correlated and the model predicts that lower values of mean absolute error (MAE) and root mean square error (RMSE) indicates that the HYDRUS-1D model is more accurate at simulating the movement of moisture under different irrigation regimes.

Crop water requirement and irrigation scheduling in Lower Kulfo Catchment of southern Ethiopia have not assessed under climate change scenarios, and the allocation of crop land also not optimal that signifcantly challenges to crop productivity.Therefore, this study was conducted to evaluate the effects of climate change on future crop water requirements, and irrigation scheduling, and to allocate cropland optimally. Bias of projected precipitation and temperature were corrected by utilizing Climate Model data with the hydrologic modeling tool (CMhyd). Alongside, crop water requirements and irrigation scheduling were assessed using Crop Water Assessment Tool. After estimating crop water requirement, crop land were allocated optimally using General Algebraic Modeling System programming with non-negativity constraints (scenario 1), and non-negativity constraints based on farmers adaptation (scenario 2). Average reference evapotranspiration from 2030 to 2050 and 2060 to 2080 was increased by 11.9 %, and 16.2 %, respectively compared with the reference period (2010–2022). The total seasonal crop water requirements were 4,529 mm, 4866.7 mm, and 5272.2 mm under 2010 to 2022, 2030 to 2050, and 2060 to 2080 climate change scenarios, respectively. The meean irrigation interval in 2010–2022, 2030 to 2050, and 2060 to 2080 climate change scenarios were 8 days, 7 days, and 5 days, respectively. This irrigation interval was decreased by 14 % (2030–2050), and 34 % (2060–2080) compared with the reference period. In 2030 to 2050 and 2026 to 2080 climate change scenarios, the required irrigation water at the inlet of main canal increased by 6.8 %, and 18 %, respectively. The optimal allocated area for tomato (60.4 %), maize (20.8 %), and watermelon (18.8 %) in scenario 1 with net benefit of 1.47*108 Ethiopian Birr. The allocated areas in scenario 2 were (48 %) for maize, (31.6 %) for tomato, and (20.4 %) for watermelon with 1.34*108 Ethiopian Birr net benefit it was reduced by 19.1 % compared with the net benefit in scenario 1. Fruit crops alone may not suffice for local food needs and to address this, small farmers should grow maize, tomato, and watermelon. This research aids policymakers in encouraging climate-resilient agriculture and improving small-scale farmers' awareness through conducting workshops and training.

Remote sensing-based surface energy balance models are widely utilized for estimating actual evapotranspiration (ETa) over large spatial scales, providing crucial information for water resource management. These models rely on the surface energy balance algorithm to estimate ETa. The objective of this study was to obtain the spatial distribution of ETa, for wheat crop in rabi season (2019–20) using the EEFlux model for a minor irrigation canal command in Bhagwatipur distributary, Bihar, India, and compare it with the CROPWAT 8.0 model (Modified Penman–Monteith Model). The EEFlux model estimated daily ETa values of 1.15 mm/day, 2.4 mm/day, 4.9 mm/day, and 3.5 mm/day during the early, vegetative, maturity, and full maturity stages of the crop, respectively. The minimum and maximum ET a values were 0.96 and 1.30 mm/day, respectively, and the average was found to be 1.15 mm on 6th January. As January is a cold month and the crop was in the development stage, the evapotranspiration demand is low. The average ET a value increases from January 6th to March 26th, with the maximum value in March varying between 3.85 and 4.79 mm/day for the selected fields, which were in the maturity stages of the crop. Besides this, in April, the ET a values decreased. Furthermore, the coefficient of determination (R2) was found to be 0.79 between the two estimation methods indicating a close agreement. Nonetheless, the Mean Bias Error (MBE) and Root Mean Square Errors (RMSEs) were also found to be 0.60 and 0.86 mm/day, respectively. Therefore, it could be inferred from these results that the EEFlux model is a good estimator of ETa for the crop, which could be used for irrigation planning in the command area to enhance the irrigation efficiency and water productivity. [ABSTRACT FROM AUTHOR]

The current investigation aims to develop a management strategy to enhance the relationship between water and food in the Euphrates River Basin, Iraq. The research methodology utilized the LARS-WG model to generate weather data for the future period (2020-2050) for the CanESM2 model. The weather data was subsequently employed in the CROPWAT model to estimate crop water requirements. Finally, the Water Evaluating and Planning (WEAP) model analyzed the greatinhabitant growth rate scenario (5%), climate change scenarios (i.e., RCP2.6, RCP4.5, and RCP8.5), and management scenarios. The WEAP model was initially calibrated and validated utilizing several statistical metrics, viz., the root mean square (RMS), Nash-Sutcliffe coefficient efficiency (NSE), and the coefficient of determination (R2). Results revealed a superior performance of the WEAP model in terms of the statistical metrics utilized. The findings illustrate that the projected water demand under RCP 2.6, RCP4.5, and RCP8.5 scenarios and the inhabitants growth scenario increased by 49%, 54%, and 56%, respectively, in the year 2050 compared to the reference scenario. In addition, the findings indicate that the water demand would decrease by 59% under the considered management scenario. Accordingly, the investigation recommends implementing water management practices, especially adaptation measures for climate change. [ABSTRACT FROM AUTHOR]

Rice is one of the most important cereal crops and is a prime target for water conservation because it is the most widely grown crop under flood irrigation. Rapidly depleting water resources threaten the sustainability of the irrigated rice production, the livelihood of rice producers and consumers, and ultimately the food security. By considering this, a field experiment was conducted with aerobic rice by evaluating different methods of planting and nutrient management practices. Treatment details are as follows: (A) method of planting, such as transplanted and direct line sowing, and (B) different nutrient management regimes (viz., T1–125% application of inorganic fertilizers; T2–100% application of inorganic fertilizers; and T3–100% application of organic manures). Results showed that, among the methods of planting, direct line sowing performed better in terms of plant growth and yield parameters. With respect to nutrient management, 125% of recommended dose of inorganic N fertilizers produced a higher yield compared to other treatments, and the difference was statistically significant. Organic manure applied as a treatment produced the lowest crop growth parameters and yield. Furthermore, water requirements for aerobic and anaerobic rice were compared using FAO-CROPWAT, and results revealed a 36.4% water saving. [ABSTRACT FROM AUTHOR]

In Algeria, vegetable crops are dependent on irrigation. In this context, the present study is oriented towards the efficient management of agricultural water that contributes to the improvement of crop production. The approach is based on the calculation of the water requirements of the potato in order to control the efficiency of the water supply in relation to the crop water requirements. This efficiency of use is imperative for a better yield and a healthy agricultural environment. In this study, we used two agronomic models CropWat (v8.0) and AquaCrop (v6.1), which were developed by FAO, to evaluate the water use efficiency (WUE) in a semi-arid climate (Wilaya of Tiaret) over a 31-year period (1990-2021). And this, by estimating the irrigation water requirements (IWR) and crop water requirements (CWR). The results obtained showed that there is a very close relationship between the estimates produced by the two models CropWat and AquaCrop. These estimates are for IWR, CWR and WUE, which are in the order of 395.91 mm, 517.24 mm, 6.47 kg m-3 using CropWat and 385.46 mm; 507.38 mm, 6.37 kg m-3 using AquaCrop. Crop growth simulation models have become important tools for evaluating and developing deficit irrigation strategies, especially in arid and semi-arid regions.

Seasonal quantification of a crop's evapotranspiration (ET) and water footprint (WF) is essential for sustainable agriculture. Therefore, this study was conducted to estimate the ET and WF of an irrigated potato crop using satellite imagery of Landsat and Sentinel-2 sensors. The Simplified Surface Energy Balance (SSEB) algorithm was used to evaluate the crop water use (ETa) for potato fields belonging to the Saudi Agricultural Development Company, located in the Wadi-Ad-Dawasir region, Saudi Arabia. Normalized difference vegetation index (NDVI), soil-adjusted vegetation index (SAVI), and land surface temperature (LSD) were computed for Landsat and Sentinel-2 datasets, which were used as inputs for mapping the potato tuber yield and, subsequently, the WF. The results indicated that the NDVI showed the best accuracy for the prediction of the potato tuber yield (R2 = 0.72, P > F = 0.021) followed by the SAVI (R2 = 0.64, P > F = 0.018), compared to the field harvested actual yield (YA). A comparison between the satellite-based ETa and the actual amount of water applied (WA) for irrigation showed a good correlation (R2 = 0.89, RMSE = 4.4%, MBE = 12.9%). The WF of the potatoes in the study area was estimated at values between 475 and 357 m3 t−1 for the early (September–December) and late (December–April) growing periods, respectively. A major portion (99.2%) of the WF was accounted for from irrigation with variations of 18.5% and 3.5% for early- and late-planted potatoes, respectively, compared to the baseline (crop planted in season). In conclusion, the results showed the possibility of satisfactorily estimating the WF using the SSEB algorithm by integrating the Landsat-8 and Sentinel-2 datasets. In general, the high rates of ET in the early planting season led to higher WF values compared to the in-season and late planting dates; this will help in selecting suitable planting dates for potato crops in the study area and areas with similar environments, which enhances the opportunities for sustainable management of irrigation water. [ABSTRACT FROM AUTHOR]

Water scarcity is a significant global problem. Considerable water resources are consumed in the production of livestock and poultry products, thus posing a huge challenge to global freshwater resources. Sheep meat has the second highest water footprint among livestock meat products. Furthermore, as the demand for sheep meat increases on a year by year basis, water consumption continues to rise as a result. In order to make better informed decisions around water management, it is necessary to estimate the water footprint of animal husbandry. This study offers a comprehensive overview of the water footprint of sheep in Northern China. It analyzes the water footprint of feed production and virtual water using CROPWAT, based on the water footprint of sheep and goats in Shanxi under different production systems and feed components. The water footprint was calculated to be 6.03 m3/kg for sheep and 5.05 m3/kg for goats, respectively. Therefore, the water footprint of three farming modes, including grazing mixed and industrial in the Shanxi region was slightly higher than what other experts have evaluated for China. These data provide crucial information that can help reduce water resource consumption in animal husbandry and contribute to the development of sustainable strategies. [ABSTRACT FROM AUTHOR]

Greengram is one of the major protein rich grain legumes predominately cultivated in North Interior Karnataka (NIK). Due to erratic nature of monsoon which has increased with climate change greengram crop is suffering from moisture stress and hence the large variability in yield levels is noticed. The study aimed at determining the water requirement of greengram variety DGGV-2 using CROPWAT model that helps the farmers of NIK consisting of 12 districts in tapping the potential yields of this crop through proper irrigation management. The results revealed that average crop evapotranspiration (ETc), effective rainfall (ER) and irrigation requirement (IR) under past climates (1991-2020) for NIK were 246, 269.3 and 37.4 mm, respectively. An increase of 26.8 mm in ETc, 21.6 mm in ER and decrease of 0.3 mm in IR were simulated under projected climates. Among the four dates of sowing (7, 14, 21 and 28th June) for greengram delayed sowing i.e., on 28th June under projected climate (2021-2050) simulated the lowest water requirement and irrigation requirement for all the 12 districts of NIK. This study proved that the CROPWAT model is useful to foresee crop water demand under projected climates and calculate the crop irrigation needs in supplement to projected rainfall for proper management of water resources and maintain crop yields. [ABSTRACT FROM AUTHOR]

Con el objetivo de determinar las necesidades hídricas del cultivo del maíz establecido en la CPA “Mártires de Barbados”, partiendo del cálculo de la evapotranspiración de referencia, se desarrolló el presente trabajo en el periodo comprendido de septiembre del 2020 a septiembre del 2021. Se desarrolló una investigación no experimental de tipo explicativa para lo cual se realizó observaciones y análisis de documentos. Se recopiló la información del comportamiento de las principales variables meteorológicas con las que se determinó la evapotranspiración de referencia, la del cultivo y el régimen de riego de proyecto con el empleo del Software CROPWAT. Fue corregido el régimen de riego y se propuso el de explotación. Como resultados principales se obtiene que las necesidades hídricas reales del cultivo del maíz no se conocen por lo que el riego se maneja de manera empírica desaprovechando una parte de las lluvias caídas, se aplica más agua de la que el cultivo requiere y es mayor el número de riegos aplicados.

The new notion of Agri (from ‘Agre’, latin for Land) – Culture (latin for Cultivation) is what made the transition of human race from primitive hunter-gatherers to more civilized and ordered societies. The invention of agriculture can be regarded as a key point in the timeline and dawn of modern civilization as we know it today. With the advent of digital electronics, we are now capable of carefully device systems to make any processes more optimized and generate significantly higher output, this is also true for the agriculture sector and many works are carried out recently aimed towards this objective and even created a new domain of precision agriculture. In this research work, an IoT-based system was developed that enables the farmers to monitor various micro-climatic parameters and assess the irrigation water requirement. The soil moisture and temperature were sensed with the aid of sensors and were fed to the LoRA system, in the receiver side, data is analyzed for the estimation of evapotranspiration. The global evapotranspiration was estimated using Cropwat software. The sensor data were analyzed using Mcguinnes-Bordne formulation and the outcome of this research work paves the way towards the estimation of the evapotranspiration in the microclimate environment.

Greengram is one of the major protein rich grain legumes predominately cultivated in North Interior Karnataka (NIK). The study aimed at determining the water requirement of greengram variety DGGV- 2 using CROPWAT model that helps the farmers of NIK consisting of 12 districts in tapping the potential yields of this crop through proper irrigation management. The decadal analysis for 60 years was done under past (1991-2020) and projected climate (2021-2050) as per the recommended practices of UAS, Dharwad across four dates of sowing from 07th June to 28th June at weekly interval. The average crop evapotranspiration (ETc), effective rainfall (ER) and irrigation requirement (IR) under past climates (1991-2020) for NIK were 246, 269.3 and 37.4 mm, respectively. An increase of 26.8 mm in ETc, 21.6 mm in ER and decrease of 0.3 mm in IR were simulated under projected climates. Sowing late i.e., on 28th June under projected climate (2021-2050) simulated the lowest water requirement and irrigation requirement for all the 12 districts of NIK. The spatial distribution of ETc, ER and IR for all the 12 districts of NIK were interpreted under both past and projected climates using ArcGIS software.

Climate change has the potential to affect climate parameters like rainfall and temperature which lead to a change in the irrigation water requirement of the irrigation system. As irrigation water requirement is highly dependent on precipitation and potential evapotranspiration, climate change impact studies are necessary. Therefore, this study aims to assess the impact of climate change on the irrigation water requirement of the Shumbrite irrigation project. For this study, climate variables of precipitation and temperature were generated from CORDEX-Africa simulations downscaled from MPI Global Circulation Model (GCM) under three emission scenarios (RCP2.6, RCP4.5, and RCP8.5). The climate data covers from 1981 to 2005 for the baseline period and 2021–2045 for the future period for all scenarios. Future precipitation shows a decrease for all scenarios with a maximum decrease under RCP2.6 (4.2%) and temperature show an increase in the future as compared to the baseline period. The reference evapotranspiration and Irrigation Water Requirements (IWR) were calculated by using CROPWAT 8.0 software. Results showed that the mean annual reference evapotranspiration is expected to increase in the future by 2.7%, 2.6%, and 3.3% for RCP2.6, RCP4.5, and RCP8.5 respectively as compared to the baseline period. Mean annual irrigation water requirement shows an increase of 2.58%, 0.74%, and 8.4% for the future under RCP2.6, RCP4.5, and RCP8.5 respectively. The Crop Water Requirement (CWR) also increases for the future period under all RCP scenarios, with maximum CWR for tomato, potato, and pepper crops. To ensure the sustainability of the project, crops with high irrigation water requirements should be replaced by other crops with low water requirements.

This research evaluated the effects of Clay Pot Irrigation System (CPIS) on water saving and water productivity compared with Drip Irrigation System (DIS) as microirrigation systems in cabbage production in Rwanda. This research was conducted at the Rwanda Polytechnic/Integrated Polytechnic Regional College Huye (RP/IPRC Huye) farm (2°35'48° S and 29°44'21° E, Elevation of 1769 m above sea level), in Huye district of Rwanda. The experimental designed was a Randomized Complete Block Design (RCBD) with three treatments and three replications. The experimental treatments were Clay pot irrigation system, Drip irrigation system, and the control treatment (No irrigation). The soil type was a sand clay loam. The clay pots used were manufactured by mixing clay and sand at the ratio of 4:1 and dried with burning dry grass. Pots were buried under the soil up to their necks, with about 2 cm of their top above the surface of the surrounding. The crop variety used for the study was Zawadi F1 of cabbage produced by the East African Co. Seed, which is adaptable under the agroclimatic conditions of the Huye district of Rwanda. Crop water requirement and irrigation scheduling were estimated by using CROPWAT 8.0 software. Organic manure (20 tons ha-1) was applied for whole trial during tillage, Nitrogen-Phosphorous-Potassium/NPK 17-17-17 (300 kg ha-1) was uniformly applied around the seedling (ring application) and Urea (300 kg ha-1) was split applied, first after three weeks of transplanting, and the second application was five weeks after transplanting. The water productivity of CPIS was 36.17 kg m-3 for DIS was 25.4 kg m-3, while the control was 31.1 kg m-3. The results of this research show that CPIS increases water productivity and water saving. Water saved is 40.23% when CPIS is compared with DIS. Clay pot irrigation system can be a viable option for water scarce areas, particularly for small-scale farmers looking to improve their productivity with their small holdings of land in sandy and drier environments. [ABSTRACT FROM AUTHOR]

Rainfall expected to occur in a given period is defined as dependable rainfall. The increasing pressure on freshwater resources necessitates efficient water use in the agricultural sector, where water is used the most globally. Therefore, dependable rainfall values in dry (80%), normal (50%) and wet (20%) periods, which are used in the planning and operation stages of irrigation networks, can be determined by analysis. In this study, the change in the irrigation water requirement of apple trees was investigated based on the dependable rainfall of Warsaw and Isparta, two important apple production regions of Poland and Turkey. For this purpose, dependable rainfall values in both locations between 1984 and 2021 were calculated monthly and annually with the Rainbow program. Then, using the climate parameters of the relevant years, plant water consumption and irrigation water requirements were calculated with the help of Cropwat software. As a result of the research, rainfall values expected to occur in the dry, normal and rainy years in Warsaw are 466 mm, 532 mm and 604 mm, respectively, while, in Isparta, these values are 422 mm, 520 mm and 602 mm, respectively. Crop water requirements calculated based on dependable rainfall are 363 mm, 237 mm and 108 mm in Warsaw during the dry, normal and wet periods, while these values are 452 mm, 367 mm and 277 mm, respectively, in Isparta. The application of appropriate irrigation rates that take into account water requirements will optimize the use of water resources and also improve apple yields. This is extremely important for these research areas in particular, as Turkey and Poland are among the largest apple producers in the world. [ABSTRACT FROM AUTHOR]

Water is one of the most important components of sustainable life. However, the excessive use of this vital element has caused irreparable damage to the limited water resources, and the agricultural industry assumed as the largest amount of consumed water. In recent years, the significant reduction of water resources as well as the growing trend of drought necessitates a review and change in the agricultural induster. In this research the water requirement of agricultural plants of Mazandaran province including rice, wheat, barley and citrus is estimated in order to investigate the volume of green and blue virtual water, exported and imported water by these crops across the province. Meteorological data such as rainfall, maximum and minimum temperature, relative humidity, sundial of the area and information such as cultivation area, crops yield rate, exported and imported water volume collected from relevant agencies over the last ten years. FAO Penman-Monteith and USDA methods in CROPWAT software used to estimate virtual water and water needs. Results showed that rice, wheat, barley and citrus consumption accounted for the largest water requirement. Also, rice water requirement is blue water and wheat, barley and citrus plants consume green water sources which is not relocated and is not suitable for other purposes or storage. Consequently, due to the climatic potential of Mazandaran province, the pattern of cultivation alter to plants with low water requirements that are able to absorb their required water from green water sources, such as wheat, barley and citrus as well as lower plant area with abundant water requirement such as rice can save more water resources and the water crisis could be effectively in control.

Irrigation water management in the paddy cultivation area under the left bank canal of the Kaudulla reservoir (Kaudulla tank) in the North Central Province of Sri Lanka has become a serious issue due to limited water availability and inefficient water distribution infrastructure at present. Insufficient storage capacities of the village tanks in the cultivation area, low rainfall during some months and regulated inflow from the transbasin diversion to Kaudulla tank have had a significant impact on yield in the two cultivation seasons of the year. In this article, modernization of irrigation infrastructure in the command area was investigated for effective utilization of limited available water. The results of the calibrated and validated Hydrologic Engineering Centre - Hydrologic Modeling System (HEC-HMS) model and Crop Water and Irrigation Requirements Program (CROPWAT) model were used with Water Evaluation and Planning Model (WEAP) to evaluate the water balance and demand to identify the best investment for improving irrigation water supply to maximize the return. Economic analysis was carried out using the net present values for different modernization options. Accordingly, the construction of a new canal system and augmentation of the capacities of village tanks from the present total capacity of 3.8–20 MCM was found to be the most appropriate option. This intervention will increase the income from yield by 205 million with a payback period of 12 years in the Yala season. HIGHLIGHTS Insufficient storage capacities of minor tanks, low rainfall during some months in the tank catchments and regulated diversion to the Kaudulla tank have had a significant impact on the cultivation area under Kaudulla tank situated in the North Central Province of Sri Lanka.; A calibrated and validated HEC-HMS model and the CROPWAT model were used with WEAP to evaluate the water balance and demand to identify the best investment for improving the irrigation system based on the economic return.;