Optimizing irrigation for Dutch roses in Beni Mellal, Morocco: Predictive modeling based on reference evapotranspiration

Accurate estimation of evapotranspiration is important in efficient water management for improving water use efficiency. In order to obtain evapotranspiration and evaporation beneath the canopy using the Food and Agriculture Organization (FAO) method, pan evaporation was used instead of reference evapotranspiration calculated by the Penman-Monteith equation with detailed meteorological data. The total crop coefficient and soil evaporation coefficient were determined using actual measured daytime evapotranspiration and evaporation by the Bowen ratio energy balance and lysimeter, respectively, in a rice paddy field in Japan. The average evapotranspiration was 5.3 mm/d, 4.4 mm/d, 7.4 mm/d and 6.3 mm/d and crop coefficient was 0.79, 1.18, 1.01 and 0.86 for the initial stage, development stage, middle-season stage and late-season stage, respectively. The evaporation was low and almost constant with an average value around 0.77 mm/d when the leaf area index (LAI) reached 3. The proposed average crop coefficients for different growing stages were applied to estimate daytime evapotranspiration and found suitable. A simple soil water evaporation coefficient model was developed using leaf area index for practical use and it was found that it could accurately estimate evaporation. Keywords: evapotranspiration, evaporation, paddy field, lysimeter, leaf area index (LAI), Bowen ratio energy balance DOI: 10.25165/j.ijabe.20171004.2290 Citation: Yan H F, Zhang C, Oue H, Peng G J, Darko R O. Determination of crop and soil evaporation coefficients for estimating evapotranspiration in a paddy field. Int J Agric & Biol Eng, 2017; 10(4): 130–139.

Evapotranspiration is a process referring to water transfer from the land to the atmosphere by evaporation, from the soil surface, and by transpiration, through the vegetation. It is a complex process of great relevance for the hydrological balance at different scales. Nevertheless, it is difficult to measure and estimate; hence, almost all evapotranspiration data contains errors. The main biophysical principles of evapotranspiration are described together with the most relevant methods for measurement and estimation. Particular attention is given to crop evapotranspiration used in irrigation scheduling and agricultural water management. The estimation of crop evapotranspiration is presented following the two‐step approach based on crop coefficient and reference evapotranspiration. The concept of reference evapotranspiration is expounded by means of the Penman–Monteith approach that combines surface energy balance and aerodynamic principles of the process. The indicative data of crop coefficient and length of crop growing stages are reported in tables for most relevant agricultural crops and the world growing regions. A detailed description of calculation procedures for the estimation of reference and crop evapotranspiration is presented together with the methods to improve crop coefficient estimate under specific growing conditions. Finally, numerical examples of reference and crop evapotranspiration are given in Appendix 1.

Sesame was grown for two successive seasons (2001/2002 - 2002/2003) at Shambat, Sudan. The aim of the study was to investigate five irrigation water quantities on actual evapotranspiration as compared with estimated evapotranspiration using Penman-Monteith method, modified Penman formula and pan evaporation. Water use efficiency and crop factors were calculated and the best water use efficiency was obtained under irrigation water 650 mm. Under all irrigation treatments, there was a large deviation of pan evaporation, modified Penman and Penman-monteith estimate from actually measured evapotranspiration. Crop coefficients were decreased with decreased water quantities in all treatments. Crop coefficients computed by pan evaporation were under all circumstances, lower than these obtained by modified Penman and Penman- Monteiths methods. Key words: Water quantities, consumptive use, water use efficiency, crop coefficient, sesame.

Understanding crop water requirements (CWR) in semi-arid region is essential for better irrigation practices, scheduling and efficient use of water since the water supply through rainfall is limited. This paper estimated the crop reference and actual evapotranspiration (Eto and ETc) respectively and the irrigation water requirement of rice (Oryza sativa L.) in Benin’s sub-basin of Niger River (BSBNR) of west Africa, using CROPWAT model. The long recorded climatic data, crop and soil data from 1942 to 2012 were computed with the Cropwat model which is based on the United Nations’ Food and Agriculture Organization (FAO) paper number 56 (FAO56). The Penman-Monteith method was used to estimate ETo. Crop coefficients (Kc) from the phenomenological stages of rice were applied to adjust and estimate the actual evapotranspiration ETc through a water balance of the irrigation water requirements (IR). The results showed the BSBNR annual reference evapotranspiration (ETo) was estimated at 1 967 mm. The lowest monthly value of ETo of 123 mm, was observed in August month, middle of the rainy season while the highest value 210 mm was observed in March within dry season. The crop evapotranspiration ETc and the crop irrigation requirements were estimated at 651 mm and 383 mm, respectively in rainy season and 920 mm and 1 148 mm, respectively within a dry season. Irrigation projects of these seasons can then be scheduled for water use efficiency based on these findings. Keywords: crop evapotranspiration, irrigation water requirement, rice, CROPWAT, model, Benin DOI: 10.3965/j.ijabe.20150802.1290

The average air temperature has been increasing in recent years. The purpose of this study was to compare meteorological differences between the 1800s and 2000s using recorded historical and modern weather data from four different time periods, each separated by approximately 60 years. Historical weather data can be used to observe climate change in recent years and in the years dating back to the early 1800s to note if there has been an acceleration of the rate of temperature change over the past two centuries. In this study, air temperatures and various aspects of precipitation were observed and compared among the four time periods. Historical weather data from 1826-1836 were obtained from a journal recorded at Erasmus Hall High School (Brooklyn, NY), digitized, and compared to data recorded during 1894-1898, 1940-1948, and 2003-2012 from various weather stations in proximity to Erasmus Hall High School. Results showed that annual mean temperatures have increased at higher rates in more recent years and that the number of extreme days each year, defined as the days with temperatures ≥ 90ºF (32.2°C) or temperatures ≤ 10ºF (-12.2°C), increased over time. The number of days with precipitation each year has also increased; however, the amount of annual precipitation has remained constant throughout the 35 years used in this study.

یکی از مهم‌ترین پیامدهای تغییر اقلیم آینده، تأثیر آن بر مصرف آب در بخش کشاورزی است که می‌تواند مدیریت منابع آب را با چالش‌های جدی روبرو سازد. در این مطالعه به‎منظور پیش‎بینی اثرات تغییر اقلیم بر رشد و نمو گندم در شش شهرستان استان خوزستان شامل اهواز، بهبهان، دزفول، ایذه، رامهرمز و امیدیه از مدل گردش عمومی HadCM3تحت سه سناریوی B1،A1Bو A2در دوره 65-2046 استفاده شد. برای ریزمقیاس کردن پارامترهای اقلیمی مولد آب و هوایی LARS-WG مورداستفاده قرار گرفت. پس از شبیه‎سازی اقلیم آینده و تولید پارامترهای موردنیاز، شبیه‎سازی رشد و نمو گندم با استفاده از مدل APSIM-Wheat انجام شد. نتایج ارزیابی مدل LARS-WG با استفاده از شاخص NRMSEحاکی از دقت بالای مدل در شبیه‎سازی تابش (از 63/0درصد تا 67/1 درصد)، دمای کمینه (از 63/0 درصد تا 98/1درصد) و بیشینه (از 63/0 درصد تا 05/1 درصد) بود درحالی‌که مقدار این شاخص برای بارندگی (از 42/11درصد تا 47/25 درصد) در مقایسه با دیگر متغیرها بالاتر بود. نتایج شبیه‎سازی نشان داد که در استان خوزستان عملکرد دانه گندم در شرایط تغییر اقلیم نسبت به دوره پایه به‎طور میانگین 16 درصد افزایش می‎یابد. با افزایش عملکرد دانه و همچنین کاهش تبخیر-تعرق (کاهش 5 درصدی در مقایسه با دوره پایه) در شرایط تغییر اقلیم، کارایی مصرف آب 23 درصد افزایش می‎یابد. به طور کلی نتایج این تحقیق نشان داد که با توجه به افزایش دما (7 درصد)، افزایش غلظتCO2(از 334 پی‎پی‎ام به 526 پی‎پی‎ام در سال 2050)، کاهش طول فصل رشد (74/7 روز) و کاهش تبخیر-تعرق نیاز آبیاری گندم در شرایط تغییر اقلیم آینده 9 درصد کاهش می‎یابد.

The far-reaching impact of climate change on water resources, particularly its intensification of scarcity, poses a substantial threat to the sustainable management of water in agriculture. To enhance cross-sectoral decision-making at various scales, it is vital to quantify both current and future water consumption, employing methodologies that assess the agricultural water footprint (WF). This study employs the Site-sPecific Agricultural water Requirement and footprint Estimator (SPARE:WATER) to evaluate the susceptibility of green and blue agricultural WF at various scales across Colombia. The assessment is conducted under two CORDEX (Coordinated Regional Climate Downscaling Experiment)-driven climate scenarios, RCP2.6 and RCP8.5. High-resolution (0.22°) CORDEX climate model projections are used to drive the SPARE:WATER model, while historical weather data from fifteen stations (1977-2005) are employed to bias-correct the model's gridded data using the Equal Quantile Matching (EQM) method. This corrected data was spatialized using IDW interpolation. Ten major crops are selected based on their national production significance, based on the National Agricultural Survey. Crop characteristics such as harvested area, yield, and crop coefficients are obtained from local and FAO sources. The analysis focuses on both green and blue WF for the near future (2060) and far future (2099), compared to the present (2020). Preliminary findings underscore a national WF of 45 km3/yr, with important variations at the departmental level. The spatial variability of WF is influenced by both wet and dry years.  Cocoa, coffee, and palm oil emerge as crops with the most substantial WF, showcasing respective water requirements of 30 k m3/t, 18 k m3/t, and 8 k m3/t nationally. Regional variations reveal the significance of crops such as plantain and banana in the agricultural WF landscape. Under the RCP2.6 scenario, the green and blue WF projections for 2060 and 2099 exhibit marginal changes relative to 2020. Conversely, under the RCP8.5 scenario, a discernible increase, particularly in blue WF, is evident, with a surge of 96% by 2099. This trajectory underscores the heightened water requirements anticipated for pivotal crops like cocoa and coffee in the future agricultural landscape. These findings underscore the urgent need for informed water management strategies in the future of Colombian agriculture, particularly in the face of a high-emission scenario. The results of this study can inform policy and decision-making aimed at ensuring sustainable water resources management and food security under the evolving climate landscape.

1. Introduction and Overview D.D. Parker, Y. Tsur. Part I: Regional Water Constraints: Middle East, California, Florida, and Australia. 2. The Israel Water Economy: An Overview D. Yaron. 3. The Jordan River Basin: Beyond National Concerns J. Kindler. 4. Water Resources in Turkey: Availability, Use, and Management E.H. Cakmak. 5. California's Water Resources and Institutions D.D. Parker. 6. Decentralized Water Allocation in Florida W.G. Boggess. 7. Australia's Water Situation: Resource Allocation and Management in a Maturing System J.J. Pigram. Part II: Economic Modeling of Decentralized Water Management Policies. A: Political Economy of Water Allocation. 8. The Political Economy of Domestic Water Allocation: The Cases of Israel and Jordan R.E. Just, et al. 9. Transboundary Water Agreements and Development Assistance G.B. Frisvold, M.F. Caswell. 10. Informational Imperfections in Water Resource Systems and the Political Economy of Water Supply and Pricing in Israel P. Zusman. 11. The Strategic Interdependence of a Shared Water Aquifer: A General Equilibrium Analysis T. Roe, Xinshen Diao. B: Water Institutions: Transition to Markets and Other Decentralized Allocation Mechanisms. 12. Designing Institutions for Water Management J. Roumasset. 13. Employing Market Mechanisms to Encourage Efficient Use of Water in the Middle East N. Becker, et al. 14. Efficient Management of Water in Agriculture D. Zilberman, et al. 15. Deriving Short-Run, Multistage Demand Curves and Simulating Market Prices for Reservoir Water Under Weather Uncertainty N. Dudley, B. Scott. 16. Water Institutions, Incentives, and Markets K.W. Easter, G. Feder. C: Incorporating Uncertainty in Resource Management Models. 17. On Event Uncertainty and Renewable Resource Management Y. Tsur, A. Zemel. 18. Quantifying Tradeoffs Between In-Stream and Off-Stream Uses Under Weather Uncertainty N. Dudley, B. Scott. 19. An Ex Ante Approach to Modeling Investment in New Technology A.P. Thurow, et al. 20. The Economics of Conjunctive Ground and Surface Water Irrigation Systems: Basic Principles and Empirical Evidence from Southern California Y. Tsur. Part III: Case Studies. 21. Peace and Prospects for International Water Projects in the Jordan-Yarmouk River Basin R.E. Just, et al. 22. Modeling the Impacts of Reducing Agricultural Water Supplies: Lessons from California's Bay/Delta Problem D. Sunding, et al. 23. Water and Conflict in the Twenty-First Century: The Middle East and California P.H. Gleick. 24. Decentralized Mechanisms and Institutions for Managing Water Resources: Reflections on Experiences from Australia W. Musgrave. Index.

Impact of rice straw mulching on water consumption and productivity of orange trees [Citrus sinensis (L.) Osbeck]

While previous studies have focused on the technical aspects of groundwater extraction and optimal cropping patterns, there is a notable lack of research on the socio-economic factors affecting groundwater access and agricultural productivity, especially at a micro-level in Punjab, India. This study, therefore, investigates the water use efficiency (WUE) and economic water productivity (EWP) of paddy and wheat crops across diverse farm sizes and districts in Punjab, offering critical insights into agricultural water management. The study is based on primary data from Punjab, India, with Sangrur, Jalandhar, Pathankot, and Bathinda districts selected for groundwater profile analysis via multistage random sampling of 246 farmers. Notably, Punjab exhibits high EWP for wheat, surpassing the national average. However, disparities exist across districts, emphasizing the importance of localized interventions. Larger farms consistently demonstrate higher WUE and EWP, underlining the significance of scale in optimizing water inputs. Factors such as farm size, crop variety, and regional variations significantly influence WUE and EWP. Tailored approaches for marginal farmers and districts with lower efficiency are crucial for promoting sustainable agricultural practices. The findings underscore the need for targeted policy interventions to enhance water use efficiency and productivity in Punjab’s agriculture sector.

Maize is the third most important grain crop in India after rice and wheat with respect to area and productivity. Water is increasingly becoming a major limiting factor for agriculture and hence efficient utilization of available water resources is most important. Drip irrigation system has substantially high irrigation efficiency as compared to surface irrigation method. In order to increase the water use efficiency and water productivity in a single crop, system basis is more important. Present study was conducted during the year 2017-18 at Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu for enhancing the water use and water productivity under maize-onion cropping system. The experimental trial was laid out in randomized block design with four replications. Maize crop was raised during kharif season and onion crop during rabi season. Treatments imposed were drip fertigation @ 50, 75, 100 and 125 per cent pan evaporation and conventional method of irrigation. The results revealed that drip fertigation methods performed better than conventional method of irrigation in maize-onion cropping system. Drip fertigation at 125 per cent pan evaporation regime in maize and onion crops recorded higher grain and bulb yield with a water saving of 29.3 and 28.8 per cent respectively as compared to conventional irrigation method. In both the crops drip fertigation at 100 per cent pan evaporation registered higher water use efficiency and water productivity. Higher net return (Rs 2,48,937) and B-C ratio (3.52) were registered in drip fertigation at 125 per cent pan evaporation followed by drip fertigation at 100 per cent pan evaporation regime.

The modern problems of irrigation sector and need of its reforms are presented as well as the importance of evaluation of reforms results via system of indicators that characterized efficiency of water use and effectiveness of water management. For this purpose, the methods of system analysis are used and the main economic and ecological factors influencing the efficiency of water use are determined. Based on the results of the system analysis an indicative assessment proposed for the following three spatial levels: for assessment of the efficiency of the irrigation sector at the national level; evaluation of water management efficiency at the level of main infrastructure and; at the level of non-state irrigation network. The efficiency of water use in irrigated agriculture at the national level is calculated as the added value in agriculture sector related to the amount of water taken for agricultural purpose. This indicator shows general productivity of water use in irrigated agriculture. Groups of ecological and economic indicators that proposed for assessing the efficiency of water use on the level of the main irrigation infrastructure allow to assess the quality of irrigation service under existing management model. For evaluation of efficiency of water use and management at the level of water users’ organizations and individual farms the following economic indicators are selected: land productivity; water productivity; irrigation area; volume of water used for irrigation; costs of irrigation and amount of production. The soil fertility and ecological state of the irrigated lands proposed as a main ecological indicator. In addition to the economic and ecological indicators the number of organizational and technological factors that provides reliability of water supply to the fields and show a effectiveness of water management should be evaluated also. The proposed integrated system of indicators can be used to evaluate the state of water use and water management in irrigated agriculture, as well as to assess the results of institutional reforms of the sector that approved by the state strategic documents.

ASCE-EWRI standardized Penman-Monteith evapotranspiration (ET) equation performance in southeastern Colorado

Determination of the water requirement and crop coefficient values of sugarcane by field water balance method in semiarid region

Introduction: Crop coefficient varies in different environmental conditions, such as deficit irrigation, salinity and intercropping. The effect of soil fertility and texture of crop coefficient and evapotranspiration of maize was investigated in this study. Low soil fertility and food shortages as a stressful environment for plants that makes it different evapotranspiration rates of evapotranspiration calculation is based on the FAO publication 56. Razzaghi et al. (2012) investigate the effect of soil type and soil-drying during the seed-filling phase on N-uptake, yield and water use, a Danish-bred cultivar (CV. Titicaca) was grown in field lysimeters with sand, sandy loam and sandy clay loam soil. Zhang et al (2014) were investigated the Effect of adding different amounts of nitrogen during three years (from 2010 to 2012) on water use efficiency and crop evapotranspiration two varieties of winter wheat. The results of their study showed. The results indicated the following: (1) in this dry land farming system, increased N fertilization could raise wheat yield, and the drought-tolerant Changhan No. 58 showed a yield advantage in drought environments with high N fertilizer rates; (2) N application affected water consumption in different soil layers, and promoted wheat absorbing deeper soil water and so increased utilization of soil water; and (3) comprehensive consideration of yield and WUE of wheat indicated that the N rate of 270 kg/ha for Changhan No. 58 was better to avoid the risk of reduced production reduction due to lack of precipitation; however, under conditions of better soil moisture, the N rate of 180 kg/ha was more economic. Materials and Methods: The study was a factorial experiment in a completely randomized design with three soil texture treatment, including silty clay loam, loam and sandy-loam soil and three fertility treatment, including without fertilizer, one and two percent fertilizer( It was conducted at the experimental farm in Jey and Qahab district of Isfahan. Reference evapotranspiration and actual evapotranspiration of maize were measured by evaporation pan method and volumetric soil water balance method using micro lysimeters, respectively. In order to accommodate the growing field conditions, a ditch with a depth of 25 cm, length of 240 cm and width of 300 cm were dug and micro-lysimeters were placed it in three rows (three replications) with a distance of 75 cm. After preparing the treatments, four seed Maize with variety of NS540 were planted at a depth of 3-5 cm on 5 August. To reduce the oasis effect on evapotranspiration, the same corn was planted in the vicinity of the project area with 500 square meters.. Results and Discussion: The results showed that using fertilizer caused increasing of crop evapotranspiration and crop coefficient of maize. Maximum of the ten-day average evapotranspiration of maize in the silty clay loam soil with two percent fertilizer was obtained 8.76 (mm/ day) on the fifth decade of growth and this value was found 45.5 percent higher than the lowest mean evapotranspiration value of the ten-day. Comparison evapotranspiration of maize in different soil fertility treatments showed that the greatest impact on increasing of maize evapotranspiration in SLF2, SCLF2, SLF2 treatments were obtained that was equal %19.1, %14.3 and %10.6, respectively (table 4). Most of the effects of fertility the crop coefficient of maize at the middle stage of growth was influenced more than other stages by the different treatments of soil fertility. Adding one and two percent of the fertilizer to treatment SCLF0 increased maize crop coefficient about 3.5 and 9.7 percent at development stage, respectively, That measured %6 and 11% for LF1 and LF2 treatments, respectively, and about 1.6 and 5.6% for SLF2 SLF1 treatment, respectively (Table 6). Comparison of maize middle crop coefficient in SLF2 and SLF1 for different soil fertility treatments showed that effect of increasing soil fertility on middle Kc of maize was more than other stages of plant growth (Table 6). The obtained results showed that the addition of one and two percent fertilizer to the silty clay loam soil increased, the middle crop coefficient 13.3% and 27%, respectively in. Conclusion: Maximum and minimum effect of soil fertility on increasing crop coefficient of maize in the middle stage was equal to 37.8% in the loamy soil and 18.3% in the sandy loam soil with two percent fertilizer. The greatest effect of soil fertility on crop coefficient of maize was measured 8.37% in the middle stage of growth in LF2. The effect of soil fertility on crop coefficient of maize in loam and silty clay loam soils more than sandy loam soil, Because can be a further organic matter in these soils (loam and silty clay loam and also decreasing evaporation in sandy loam soil.