Water Requirements Research Articles

Effect of Varying Irrigation Levels on Growth and Yield of Serengeti and Theresa French Bean Cultivars: A Case Study in Huye District, Rwanda

Effective irrigation management is essential for maximizing crop yield and quality while conserving water resources. This study evaluated the impact of varying irrigation levels on the growth and yield of two French bean cultivars, Serengeti and Theresa, conducted in 2024 at the Agricultural Research Center of Rwanda Polytechnic–Huye College. Key objectives included determining crop water requirements, establishing irrigation schedules based on daily soil water balance, and examining the effects of three irrigation regimes (Full irrigation (100% ETc), Deficit irrigation( 50% ETc), and Rainfed as Control on yield parameters across both cultivars. The experiment followed a split-plot design in a Randomized Complete Block Design with three replications. Soil moisture levels were monitored using PR2- Moisture Sensors. The results of conducted field experiments revealed that the seasonal irrigation water requirements for full irrigation, deficit irrigation, and rainfed treatments were 111.38 mm, 99.5 mm, and 24.5 mm, respectively. Seasonal evapotranspiration rates were measured at 160.4 mm for full irrigation, 143.9 mm for deficit, and 80.84 mm for rainfed. The fresh pod yield ranged between 5.9 – 11.7 tons ha⁻¹ for Serengeti and 5.3 – 20.3 tons ha⁻¹ for Theressa, while dry matter yields varied from 1.0 – 1.66 tons ha⁻¹ for Serengeti and 0.8 – 2.88 tons ha⁻¹ for Theressa. Plant height ranged from 22 cm to 40.1 cm, and pod lengths for Serengeti and Theressa were between 9.3 – 17.64 cm and 8.8 – 15.8 cm, respectively. The mean number of grains per pod was 7. Yield response factors (ky) for Serengeti and Theressa were 1.029 and 1.20, respectively. The highest crop evapotranspiration productivity (WPET) and water productivity (WP-irrigation) were recorded for Theressa at 127.2 kg ha⁻¹ mm⁻¹ and 135.6 kg ha⁻¹ mm⁻¹, respectively. Monitoring soil moisture balance highlights the economic advantages of efficient irrigation techniques tailored to local conditions.

Impacts of Climate Changes on Spatiotemporal Variation of Cotton Water Requirement and Irrigation in Tarim Basin, Central Asia.

Evapotranspiration (ETc), crop water requirement (Dcr), irrigation (IR) and irrigation leaching amount (IRlc) play a critical role in optimizing irrigation scheduling and are also important for hydrological cycle processes and ecological environment in arid regions. This research examined the spatiotemporal variability of the ETc, Dcr and IR of cotton using data from 16 meteorological stations in the Tarim basin (TRB) of arid Northwest China during 1961-2017. The results showed that the mean annual ETc of cotton exhibited a significant decreasing trend, with a change rate of 12.965 mm·10 a-1 and 18.357 mm·10 a-1 during 1961-2017 and 1961-1990, respectively. Subsequently, it experienced a substantial increase with a change rate of 16.833 mm·10 a-1 after 1990. The Dcr of cotton followed a decreasing trend at a rate of 15.531 mm·10 a-1 and 21.99 mm·10 a-1 during 1961-2017 and 1961-1990, respectively. The Dcr of cotton provided an increasing trend at a rate of 20.164 mm·10 a-1 during 1991-2017. The IR of cotton followed a decreasing trend at a rate of 19.66 mm·10 a-1 in 1961-2017 and 24.531 mm·10 a-1 in 1961-1990, but an increasing trend at a rate of 14.437 mm·10 a-1 in 1991-2017. The IRlc of cotton decreased by 2.566 mm·10 a-1 and 3.663 mm·10 a-1 during 1961-2017 and 1961-1990, respectively. After 1990, it experienced a substantial increase by 3.331 mm·10 a-1. Wind speed exerted the greatest influence on the variability in Dcr and IR between 1961 and 1990, while shine hour played a more prominent role in explaining the variability in Dcr and precipitation may have played a more significant role in explaining the variability in IR. This study is helpful for the scientific planning for agriculture, water resource allocation and water-saving irrigation in arid regions.

Mitigation strategies of salicylhydroxamic acid collector with oxalic acid in goethite flotation

Flotation of goethite, a representative mineral of laterite ore, which is essential source of nickel used in secondary batteries, was conducted using salicylhydroxamic acid as the collector. The presence of ferric ions derived from goethite in the pulp resulted in an increased consumption of the collector during flotation. Following three washing stages, the maximum recovery of 98.5 wt% was achieved with a collector dosage of only 60 % in the absence of a washing stage. The oxalic acid is employed to eliminate ferric ions via precipitation without the requirement for supplementary water, energy, and time-consuming washing stages. The utilization of 40 g⋅t−1 of oxalic acid yielded comparable recovery outcomes to those observed in the three washing stages. Furthermore, theoretical investigations were conducted to determine the collector species influencing goethite flotation with density functional theory. It was observed that compared with that of goethite with non-ionized salicylhydroxamic acid complex, the complexation energy for goethite with ionized salicylhydroxamic acid was lower by 113.9 kJ⋅mol−1, indicating that the optimum adsorption onto the mineral surface strongly depends on ionized salicylhydroxamic acid species. This study presents a potential method for reduction of reagent consumption in the flotation of future complex laterite ore, an acidic soil in which metal ions might be present. Additionally, the theoretical framework elucidates the complexation of collectors to minerals that are challenging to quantify experimentally.

Development and evaluation of site-specific evapotranspiration models in Malawi through a comparative analysis of existing models

Locally based information on reference evapotranspiration pertinent to efficient irrigation water management is scarce in developing countries. This compromises the accuracy in determining irrigation crop water requirements since most existing reference evapotranspiration models are empirically based and less accurate unless calibrated to local conditions. The FAO Penman-Monteith equation has been proven to estimate reference evapotranspiration for different environments worldwide. However, its intensive data input requirements impede utilization of the model in developing countries due to inadequate climate data collection and management capacities. Therefore, a need existed to develop site-specific models that are less data intensive. A study was conducted aimed at developing site-specific evapotranspiration models using comparative analysis of the Kharrufa, Linacre, Hargreaves Original and Hargreaves Modified empirical models during the wet and dry season. Performance of each model was compared with the FAO Penman-Monteith model, regarded as the standard model. The models whose Root Mean Square Error (RMSE), Mean Bias Error (MBE) and coefficient of determination (R2) were satisfactory were selected. The selected models were developed statistically through regression analysis. Performance of the Kharrufa model was satisfactory comparatively as observed from its RMSEs of 1.02 mm/day and MBE -0.34 to 0.8 for the dry season. However, the model less accurately estimated reference evapotranspiration during the wet season (RMSE 2.18 mm/day and MBE 1.03 to 2.13). The study recommends the use of the Kharrufa model in the study locations in dry seasons while utilization in wet season may require further studies to ascertain the model's useability and reliability.

Coping strategies for household water insecurity in rural Gambia, mediating factors in the relationship between weather, water and health

BackgroundRural communities in low- and middle-income countries, such as The Gambia, often experience water insecurity periodically due to climate drivers such as heavy rainfall and reduced rainfall, as well as non-climate drivers such as infrastructural issues and seasonal workloads. When facing these challenges households use a variety of coping mechanisms that could pose a risk to health. We aimed to understand the drivers of water insecurity (climate and non-climate), the behavioural responses to water insecurity and the risks these responses pose to the health of communities in rural Gambia and map these findings onto a conceptual framework.MethodsWe interviewed 46 participants using multiple qualitative methods. This included in-depth interviews and transect walks. A subset of 27 participants took part in three participatory pile-sorting activities. In these activities participants were asked to rank water-related activities, intrahousehold prioritisation of water, and the coping strategies utilised when facing water insecurity.ResultsMultiple strategies were identified that people used to cope with water shortages, including: reductions in hygiene, changes to food consumption, and storing water for long periods. Many of these could inadvertently introduce risks for health. For example, limiting handwashing increases the risk of water-washed diseases. Deprioritising cooking foods such as millet, which is a nutrient-dense staple food, due to the high water requirements during preparation, could impact nutritional status. Additionally, storing water for long periods could erode water quality.Social factors appeared to play an important role in the prioritisation of domestic water-use when faced with water shortages. For example, face-washing was often maintained for social reasons. Health and religion were also key influencing factors. People often tried to protect children from the effects of water insecurity, particularly school-aged children, but given the communal nature of many activities this was not always possible. Many people associated water insecurity with poor health.ConclusionsTo reduce the risks to health, interventions need to address the drivers of water insecurity to reduce the need for these risky coping behaviours. In the short term, the promotion of behavioural adaptations that can help buffer health risks, such as water treatment, may be beneficial.

Synergistic impact of vermicompost and different woody-biochar boosts eggplant growth traits and physiological-related parameters under deficit irrigation

ABSTRACT Water scarcity is a major environmental stress that negatively affects the soil traits, growth of plants, and yield of crops. This research assessed the impact of vermicompost, oak tree biochar, apple tree biochar, and the combined impact of vermicompost and both biochars on the growth, water use efficiency (WUE), and yield of eggplant under conditions of limited irrigation. The main purpose of the study was deficit irrigation, which involved 3 levels of water supply: 50%, 75%, and 100% PWR (plant water requirement). The second focus was on the application of vermicompost, with two levels: 0 and 2000 gm−2, as well as biochar, with two levels: 0, 400 gm−2 of oak-tree biochar, and 400 gm−2 of apple tree biochar. The findings revealed that the combination of apple-tree biochar and vermicompost at a level of 100% PWR, delivered the most positive results in terms of plant growth and functioning. The early harvest yield was greatest when apple-tree biochar was applied alone at a level of 50% PWR. However, the total yield of the plant was highest when apple-tree biochar and vermicompost combined were applied at a level of 100% PWR. The plant's WUE reached its highest level after the combined application of apple-tree biochar and vermicompost at a level of 50% PWR. The maximum leaf levels of N, P, K, Fe, and Mg were observed when both vermicompost and apple-tree biochar were applied at a level of 100% PWR. The treatments without amendments or with vermicompost only at a level of 50% PWR exhibited the highest values of physiologically significant stress metabolites.

Design of Integrated Energy–Water Systems Using Automated Targeting Modeling Considering the Energy–Water–Carbon Nexus

The swift expansion of the global population and economy has spurred growing requirements for energy and water in recent decades. Inefficient energy and water consumption, however, has led to an increase in CO2 emissions. Hence, the socio-economic development of a country must consider the interconnections between energy, water and carbon, as there are mutual dependencies among these three elements. This work considers the nexus between energy, water and carbon in the design of integrated energy–water systems using a new automated targeting modeling (ATM) framework. ATM incorporates the advantages of the insight-based Pinch method and a mathematical programming approach to provide visual understanding for a thorough analysis of the problem while guaranteeing accurate solutions. Minimum targets of power and water based on the integrated network operation were established by the ATM, with corresponding carbon emissions. A specific goal of annual carbon emissions reduction was set as the constraint and the ATM optimized the capacities of the components in the system accordingly to achieve minimum overall cost. The application of ATM on an industrial plant case study shows that a target of 45% reduction in the carbon discharge amount was achieved by shifting to greener fuel in the energy system at a minimum overall cost increase of 0.45% only. The framework can assist users in meeting power and water loads in their plant while planning for the appropriate decarbonization efforts at the minimum possible cost.

Impact of climate change on vegetation growth trends in a citrus farmland in the south-eastern Sicily

Abstract. The environmental repercussions of climate change triggered substantial alterations in existing ecosystem balances leading to a gradual reduction in biodiversity and the increasing degradation of soil and the built environment. This has a direct effect on agricultural production in particular, leading to increased crop water requirements, the spread of new pests and pathogens that are difficult to manage, and, thus, a general reduction in productivity. Through the analysis of multispectral data remotely sensed with latest generation of optical sensors (RGB, thermal, NIR and multi-spectral cameras), it is possible to recognize the health status and growth stages of crops. In fact, in relation to the amount of radiation reflected in the different bands it is possible to calculate spectral indices, or vegetation indices. The main vegetative indices are NDVI, SAVI, MSAVI2, GNDVI and NDRE, which are calculated by differentially combining the ultraviolet spectrum, the visible range, and the near and mid-infrared band.In this paper the outcomes of a multi-year monitoring of a citrus grove field near Rosolini (Syracuse), in south-eastern Sicily-Italy, are presented. This monitoring activity was conducted to highlight areas of productive greenery under stress, on which to act as a priority with specific agronomic interventions. In parallel with the direct monitoring phases of the citrus grove, the trend of average monthly and annual temperature and precipitation values over the past 24 years was also studied to more specifically contextualize the possible presence of significant variations in climatic trends and relate them to the results returned by the calculation of the indices.

Comprehensive Review of Crop Water Requirement Estimation Techniques: Approaches, Challenges, and Future Directions

In order to meet the growing demand for water, water scarcity is a significant issue that needs attention. Agriculture crops are not getting enough water because of this problem. Consequently, figuring out how much water a given crop needs requires using the right method. Accurate crop water requirements must be measured in order to schedule irrigation effectively, which in turn leads to efficient crop water management. To restore the lost moisture and promote the best possible growth for plants, irrigation is used. Water management and irrigation scheduling fundamentally depend on an accurate calculation of the crop's crop water requirements (ETc). Accurate evapotranspiration measurements are necessary for effective irrigation water management. Evapotranspiration (ET), a process that measures the amount of water lost from soil and crops through transpiration and evaporation processes, respectively, is dependent on a variety of meteorological factors. A significant factor in determining crop water requirements and irrigation schedules is reference evapotranspiration. There exist multiple theories and methodologies for estimating reference evapotranspiration, ranging from empirical to physical based. Reference Evapotranspiration is referred to the idea behind ET is to calculate ET based on a reference surface that is comparable to a deep surface of green grass that is consistently growing, completely covering the surface with enough water, and looking stable. The goal of irrigation futures is to choose a suitable model for estimating reference crop evapotranspiration. In order to calculate the amount of water needed for a crop, multiply ETo by the crop coefficient (Kc), which is dependent on the phases and length of a crop's growth. Regression, fuzzy logic, Penman-Monteith, Blaney-Criddle, Hargreaves, ANN and WNN, and other conventional and non-traditional methods are used to estimate ETo.

Experimental investigation in a forced draft wet cooling tower using aluminum oxide nano particles

Cooling towers are used in industries to remove the excess heat produced by industrial processes and machineries. This cooling phenomenon and its rate can be improved by mixing it with the nanoparticles. The present work focuses on the design and construction of a counter flow forced draft cooling tower with the addition of aluminum oxide (Al2O3) nanoparticles with water to enhance heat & mass transfer. Experiments are performed with the variation of the flow rate of water, water temperature, and the volume fraction of nanoparticles from 0 % to 2 % by volume fraction. The output parameters like coefficient of performance (COP), cooling characteristics coefficient (CCC), Rate of evaporation (ER), cooling tower efficiency & range have been analyzed. Nanofluid properties like viscosity, density & thermal conductivity for different volume fractions have been examined. It is observed that viscosity and thermal conductivity increased with an increase in volume fractions. Viscosity decreased whereas conductivity increased with temperature rise. Results obtained from cooling tower experiments indicated a maximum COP, CCC, ER, efficiency, and range equal to 7.12, 3.54, 3.95 g/s, 75.55 %, and 29.8ᵒC, respectively. For the various volume fractions studied, nanofluid with 2 % outperformed others with higher heat transfer rates and range values. For the 2 % volume fraction of the nanoparticles, make-up water requirements reduced by 76.19 % when it is compared to the normal water without the nanoparticles. Also, it is found that the cooling tower range, heat transfer rate, and efficiency increased by 10 %, 10.2 %, and 4.16 % when nanofluid concentration is varied from 0 % to 2 % by volume for the air velocity and water flow rate of 13 m/s and 3.5 Liters per minute (LPM) respectively.

Studying the Combined Impact of Salinity and Drought Stress-Simulated Conditions on Physio-Biochemical Characteristics of Lettuce Plant

Water scarcity and increasing salinity stress are significant challenges in the farming sector as they often exacerbate each other, as limited water availability can concentrate salts in the soil, further hindering plant growth. Lettuce, a crucial leafy vegetable with high nutritional value, is susceptible to water availability and quality. This study investigates the growth and development of lettuce plants under water scarcity and varying levels of salinity stress to identify effective strategies for reducing water consumption while maintaining or improving plant productivity. Field experiments were designed to simulate three drought levels (50, 75, and 100% of class A pan evaporation) and three salinity stress levels (control, 1500, and 3000 ppm NaCl), assessing their impact on lettuce’s morphological and biochemical parameters. The combination of reduced water supply and high salinity significantly hindered growth, underscoring the detrimental effects of simultaneous water deficit and salinity stress on plant development. Non-stressed treatment enhanced nitrogen, phosphorus, and potassium contents and progressively decreased with the reduction in water supply from 100% to 50%. Interestingly, higher salinity levels increased total phenolic, flavonoid, and antioxidant activity, suggesting an adaptive stress response. Moreover, antioxidant activity, evaluated through DPPH and ABTS assays, peaked in plants irrigated with 75% ETo, whether under control or 1500 ppm salinity conditions. The Yield Stability Index was highest at 75% ETo (0.95), indicating robust stability under stress. The results indicated that lettuce could be cultivated with up to 75% of the water requirement without significantly impacting plant development or quality. Furthermore, the investigation demonstrated that lettuce could thrive when irrigated with water of moderate salinity (1500 ppm). These findings highlight the potential for reducing water quantities and saline water in lettuce production, offering practical solutions for sustainable farming in water-scarce regions.

District Level Crop Weather Calendars and Advisories for Kharif Rice in Odisha, India

The crop weather calendar is a visual depiction of key facts about crop growth phases, typical crop water requirements, and alerts that should be sent out in response to weather that is conducive to the spread of pests and diseases. Farmers and other stakeholders may successfully plan crops, schedule irrigation, and take plant protection measures by using these calendars, which are practical and helpful tools for farmers. The crop weather calendars are prepared in different languages for better understanding to farmers and explain the usage importance and plan farm operation and activities by taking decisions as per the prevalent crop weather conditions in fields. It plays a vital role for important crops and various varieties through research & development-based process at village/ panchayat level. It also helpful for improving the quality of medium range weather forecast based on Agro-Advisory Services (AAS). The AAS provides strategies based on weather for crop and livestock management to increase production and food security. The AAS has been useful to advise farmers regarding farm operations to manage the inclement weather for effective crop production in the changing environment. The Research was carried out on the studies of crop weather calendar on Rice crop in different districts of Odisha by All India co-ordinated research project on Agrometeorology, Bhubaneswar centre with the support of Agro Meteorological Field Unit (AMFU). It has been prepared with an objective to study climate normal of past 30 years from (1993-2023). Climatic data of Rice crop in Kharif season has been taken 25th SMW to 42nd SMW for medium duration (125 days) and 26th to 49th SMW for long duration (150 days) Rice crop in both English and Odia (local) languages for the coastal districts i.e (Khordha, Puri, Kendrapada and Jagatsinghpur) of Odisha. From the crop weather calendar the medium duration of rice crop, it was found that for sowing to seeding the mean temperature is 290C, before the transplanting and the water requirement of 670-690 mm is found congenial for better yield of the crop. The growth of the crops severely affected where the temperature falls below 200C, for high yielding of Rice crop during the kharif season the favourable weather conditions are Tmax: 300C, Tmin: 260C, Rainfall: 78 mm to 110 mm during the 29th to 30th week with RH 87%. For the pest likes stem borer and leaf folder the congenial weather conditions are Temperature :20 to 300C, RH:87%, Wind speed (Km/h) <5 and Rainfall: 00-30 mm. Similarly for Blast and BLB diseases, the favourable conditions during the 28th-31st week to 48th week, when the temperature range 20-300C, RH=> 90 %, Wind speed < 5 (Km/h) RH:30-50%. It has been found that the severity of pest and diseases increases with decreases in temperature and High RH and very low rainfall.

Salicylic acid altered the fatty acids compositions and nutrient status of shallot (Allium hirtifolium) grown under drought stress

In arid and semi-arid regions, water shortage is a persistent challenge, significantly affecting plant growth and productivity. To mitigate the detrimental effects of drought, the use of plant growth regulators, such as salicylic acid (SA), has proven to be an effective strategy for enhancing plant resilience, as well as improving yield and quality. This study aimed to investigate the impact of SA on the nutrient composition, yield, and overall quality of shallot plants over three cropping seasons (2020, 2021, and 2022) under drought stress conditions. A split-plot design with four replicates was employed, where irrigation levels (0 %, 50 %, 75 %, and 100 % of the plant's water requirements) were the main factor, and varying concentrations of SA (0, 0.5, 0.75, and 1 mM) were the secondary factor. The results revealed that drought stress increased the concentrations of key micronutrients—iron, copper, sodium, potassium, manganese, and zinc—while reducing magnesium content, ash content, and overall yield. However, the application of SA counteracted these effects by significantly enhancing magnesium content, ash content, and yield in shallot plants. In addition, drought stress increased the levels of palmitic, palmitoleic, and oleic acids while reducing the levels of stearic, linoleic, and linolenic acids. The highest concentrations of linoleic acid (ω6, 110.1 mg) and linolenic acid (ω3, 24.242 mg) were recorded under full irrigation and 75 % water requirement treatments, respectively. SA application further enhanced the levels of stearic, oleic, and linoleic acids, improving the overall nutritional quality of shallot plants. In conclusion, the application of optimal concentrations of SA significantly improves the yield, quality, and nutritional value of shallot plants under drought stress, making it a valuable approach for managing water stress in agriculture.

Grapevine and maize: Two guard cell shaped strategies to cope with repeated drought stress

Adaptation of crops to recurrent drought stress is crucial for maintaining agricultural productivity and achieving food security under changing climate. Guard cells, pivotal regulators of plant water usage and assimilation, are central to this adaptation process. However, the metabolic dynamics of guard cells under drought stress remain poorly understood, particularly in grapevine, a prominent crop grown in arid regions, and maize, a staple crop with substantial water requirements. In this study, differences in guard cells metabolism during drought stress of grapevine and maize were investigated by performing physiological and metabolomic analyses. Metabolomic analysis highlighted differential responses in amino acids and sugars, with grapevine guard cells displaying greater stability in amino acid and sugar signatures, while maize showed marked increases in sugar levels. These findings suggest two distinct adaptive strategies, a vigorous acclimation of guard cells, as observed in maize, and an attenuated acclimation of guard cells, shown in grapevine. Understanding these metabolic adjustments is helpful for enhancing drought resilience in agricultural systems.

EFFECT OF WATER STRESS ON YIELD AND YIELD COMPONENTS OF PEANUT CULTIVARS

To evaluate the effect of irrigation regimes on yield and water productivity, a split plot experiment was conducted with three replications in Iran in 2017 and 2018. The main treatment consisted of 40%, 60%, 80% and 100% water requirements, respectively, and the sub-treatment consisted of four peanut cultivars which are types of peanuts that are cultivated in Iran market (Guil, Gorgani, Jonobi and Mesri). Each 100 grams of these introduced peanuts contains 25.5 grams of protein and 48.4 grams of fat. Seed yield in 2017 with an average of 1316 kg ha-1 was higher than seed yield in 2018 with an average of 1022 kg ha-1 Due to irrigation, seed yield in the treatments of 40% and 60% of water requirement with the average of 1345kg ha-1 and 1379 kg ha-1, respectively, had the highest value. Due to the year of irrigation, the maximum seed yield in 2017 and in treatments of 40% and 60% of water requirement were with an average of 1494 kg ha-1 and 1593 kg ha-1, respectively. In peanut cultivars, Jonobi cultivar with an average of 1273 kg ha-1, had the highest value compared to other cultivars. Due to irrigation×cultivars, 40% water requirement treatment and Jonobi cultivar with an average of 1732 kg ha-1, and also 60% water requirement treatment and Guil cultivar with an average of 1667 kg ha-1 had the highest value. The maximum seed yield due in year ×irrigation ×cultivar was in 2017, and in the treatment of 40% of water requirement and in the Jonobi cultivar with an average of 1856 kg ha-1. Water productivity on biological yield (4.32 kg m-3) and pod yield (1.96 kg m-3) in Mesri cultivar and Water productivity on seed yield in Gorgani cultivar were 0.54 kg m-3.

Modeling tree responses to soil water variability guides irrigation to account for soil winter reserves

AbstractHigh‐yield almond (Prunus amygdalus) production requires irrigation to support soil water availability throughout the summer. We aimed to develop tools that project almond trees’ water requirements and then integrate them into irrigation management. We postulated that deficit irrigation would limit root allocation and reduce irrigation efficiency. Thus, we monitored soil water availability (soil water content and potential evapotranspiration) and tree physiology (transpiration and trunk circumference) under 600, 900, or 1250 mm summer irrigations. A soil‐tree model was trained to predict trees’ transpiration as the soil dried between irrigation events. The model included an empirical function for tree transpiration at variable soil water potentials (50% loss by −1 MPa). Field records corroborated the soil‐tree model projections that 600 mm irrigation reduces soil water potential to −1 MPa and limits transpiration after winter soil water reserves deplete. Trees at deficit irrigation did grow deep roots to extract soil winter reserves, thus disputing our original notion. A 900 mm irrigation matched transpiration and maintained soil at −0.6 MPa. The 1250 mm irrigation exceeded transpiration and narrowed trees’ water uptake to the upper 50 cm. The reciprocity between soil water and transpiration dictates that predetermined irrigation would limit or exceed transpiration. The soil‐tree model could project transpiration responses to soil water variability, thereby supporting irrigation by trees’ transpiration. The model uses soil water dynamics, rather than insular water potential measures, to account for spatial discrepancies between water application and uptake depths. Hence, the soil‐tree model lays a computational framework for precision irrigation by automated sensory.

Study on optimization of maize irrigation scheduling in Shaanxi Province

With the impact of climate change in recent years, the instability of precipitation and the increase of evaporation have made water resources in Shaanxi Province more and more stressed. How to maintain stable economic development while ensuring the sustainable development of agriculture within the limited water resources has become an important issue facing Shaanxi Province. This paper analyzes the temporal and spatial distribution characteristics of maize irrigation water requirement in Shaanxi Province based on meteorological data and obtains the ideal irrigation water requirement. However, considering the agricultural water scarcity issue in this region, this paper establishes different water scarcity scenarios, adopts the Jensen model to construct an objective function aimed at minimizing crop yield reduction, and solves it using a genetic algorithm to obtain the optimized maize irrigation scheduling under different water scarcity scenarios. The results analysis indicates the following: (1) The effective rainfall in Shaanxi Province from 1960 to 2019 shows a slight upward trend, while the maize water requirement and maize irrigation water requirement shows a downward trend. (2) The spatial distribution of maize irrigation water requirement in Shaanxi Province decreases gradually from north to south. High-value areas are mainly distributed in the northern regions of Yulin City and Yan’an City in Shanbei. Low-value areas are distributed in Ankang City in Shannan. (3) In the face of water scarcity, spring maize should ensure water use during the middle growth period, fast development period, and initial growth periods. Under the same water scarcity conditions, the yield reduction rate is the highest in Guanzhong, followed by the Shannan, and the lowest in Shanbei. This paper aims to provide a scientific and reasonable optimization plan for maize irrigation in Shaanxi Province by calculating and analyzing the maize irrigation water requirement in Shaanxi Province, combined with optimization tools such as genetic algorithms, to address the challenges brought by water resource constraints.

Optimizing Water Productivity through the Conjunctive Use of Borewell and Canal Water for Enhancing Sheep Productivity in Arid Climate of Western Rajasthan, India

In the arid regions of Rajasthan, water scarcity poses a significant challenge to both agriculture and livestock productivity. Sustainable practices in such climates require effective management of limited water resources. This study focuses on optimizing water productivity through the conjunctive use of canal water and borewell water to address the problem of water scarcity while maximizing output per unit of water. The experiment involved eighteen healthy lambs of aged 2-3 months which were managed intensively and divided into three groups of six lambs each based on a randomized block design. All groups were fed Pennisetum glaucum (pearl millet) and Medicago sativa (lucerne) ad-libitum along with concentrates adjusted according to their body weights. The groups were offered three types of drinking water: canal water (G1), a combination of canal and borewell water (G2) and borewell water (G3) in a clean bucket twice a day. No significant effect on total feed intake and body weight of the lambs was found based on the drinking water source. However, G1 and G2 lambs, which were offered canal water, consumed significantly (p<0.05) less water (74.4 ± 1.84 liters) compared to the lambs in G3 (81.6 ± 1.91 liters). The virtual water requirement per kilogram of weight gain, calculated from both direct water intake and indirect intake through feed was lowest in G1 lambs (5771.34 liters) followed by G2 lambs (6129.00 liters) and G3 lambs (6312.00 liters) per kilogram of weight gain, respectively. These results indicate that water productivity was highest with canal water (G1) and lowest with borewell water (G3) per kilogram of weight gain. This study underscores the importance of efficient water management in maximizing productivity and resource use efficiency in water-limited arid regions.

A closed-loop sustainable method for the fabrication of electrospun nanofiber using food waste for filtration of particulate matters (PMs) and volatile organic matter (VOCs) from air

Indoor air pollution significantly impacts human health and the environment. Humans suffer the greatest health burden due to inefficient combustion technologies and polluted fuels. Therefore, air filtration is essential for a healthy and prosperous household. This study aims to develop a sustainable approach for the fabrication of biodegradable electrospun nanofibers (ENs) as air filters from food waste materials and offer a closed-loop circular solution and potential replacement for non-biodegradable HEPA air filters. We have tested banana peel extract (BPE), eggshell membrane, chitosan, and starch blended with polyvinyl alcohol (PVA) for fabricating ENs. Among the nanofibers investigated for air filtration application, BPE/PVA nanofiber shows the best performance in terms of maximum particulate matter (PM) removal efficiency and minimum pressure drop while incorporating > 50% of the food waste into the electrospinning solution. Adding BPE into a 10% PVA solution leads to a reduction in the hydrophilic behavior of the BPE/PVA nanofiber as compared to neat 10% PVA ENs. The BPE/PVA nanofiber shows minimum pressure drop (156–160 Pa) and highest quality factor (Qf) in comparison with other waste-derived nanofibers with > 98% filtration efficiency of PM2.5. Further, BPE/PVA nanofiber shows the highest adsorption of xylene vapor among other food waste derived nanofibers studied. Based on the above results, it can be concluded that BPE based nanofiber shows the best performance as air filter media among all other food waste-based ENs. The study demonstrates a successful regeneration and reuse of the BPE/PVA filter up to 3 cycles. The leftover material from banana peels after BPE extraction was utilized as a soil ameliorant. It showed 55% soil water retention (SWR) capacity, making it possible to apply in arid regions or crops with high water requirements.

Land Suitability Assessment and Crop Water Requirements for Twenty Selected Crops in an Arid Land Environment

Expanding projects to reclaim marginal land is the most effective way to reduce land use pressures in densely populated areas, such as Egypt’s Nile Valley and Delta; however, this requires careful, sustainable land use planning. This study assessed the agricultural potential of the El-Dabaa area in the northern region of the Western Desert, Egypt. It focused on assessing land capability, evaluating crop suitability, mapping soil variability, and calculating crop water requirements for twenty different crops. In this work, we evaluated land capability using the modified Storie index model and assessed soil suitability using the land use suitability evaluation tool (LUSET). We also calculated crop water requirements (CWRs) utilizing the FAO-CROPWAT 8.0 model. Additionally, we employed ArcGIS 10.8 to create spatial variability maps of soil properties, land capability classes, and suitability classes. Using a systematic sampling grid, 100 soil profiles were excavated to represent the spatial variability of the soil in the study area, and the physicochemical parameters of the soil samples were analyzed. The results indicated that the study area is primarily characterized by flat to gently sloping surfaces with deep soils. Furthermore, there are no restrictions on soil salinity or alkalinity, no sodicity hazards, and low CaCO3 levels. On the other hand, the soils in the study area are coarse textured and have low levels of CEC and organic matter (OM), which are the major soil limiting factors. As a result, the land with fair capability (Grade 3) accounted for the vast majority of the study area (87.3%), covering 30599.4 ha. Land with poor capability (Grade 4) accounted for 6.5% of the total area, while non-agricultural land (Grade 5) accounted for less than 1%. These findings revealed that S2 and S3 are the dominant soil suitability classes for all the studied crops, indicating moderate and marginal soil suitabilities. Furthermore, there were only a few soil proportions classified as unsuitable (N class) for fruit crops, maize, and groundnuts. Among the crops studied, barley, wheat, sorghum, alfalfa, olives, citrus, potatoes, onions, tomatoes, sunflowers, safflowers, and soybeans are the most suitable for cultivation in the study area. The reference evapotranspiration (ETo) varied between 2.6 and 5.9 mm day−1, with higher rates observed in the summer months and lower rates in the winter months. Therefore, the increase in summer ETo rates and the decrease in winter ones result in higher CWRs during the summer season and lower ones during the winter season. The CWRs for the crops we studied ranged from 183.9 to 1644.8 mm season−1. These research findings suggest that the study area is suitable for cultivating a variety of crops. Crop production in the study area can be improved by adding organic matter to the soil, choosing drought-resistant crop varieties, employing effective irrigation systems, and implementing proper management practices. This study also provides valuable information for land managers to identify physical constraints and management needs for sustainable crop production. Furthermore, it offers valuable insights to aid investors, farmers, and governments in making informed decisions for agricultural development in the study region and similar arid and semiarid regions worldwide.