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Snowfall/cover and snowmelt are essential determinants of winter soil processes/events that may force the biogeochemical dynamics of soils in temperate regions. Increasing variability of the European hydroclimate is expected to lead to more frequent intermittent warm periods, which cause snowmelt during winter and rapidly mobilize large amounts of dissolved organic matter (DOM). This study, conducted at the Hainich Critical Zone Exploratory in Germany, seeks to address a significant gap in understanding the molecular impacts of snowmelt-induced DOM flows and their ability to alter soil ecosystems rapidly. During two snowmelt events between January and March 2021, we observed that DOM concentration and composition varied more in forest soil seepage than in grassland soil seepage. Forest seepage showed a pronounced DOM flux peak and synchronous increases in the relative abundances of aromatic DOM components, indicating surface-derived transport of plant litter carbon. In the grassland, however, peak DOM fluxes were characterized by a marked increase in nitrogen-containing (N-containing) DOM components, indicating a predominance of microbial carbon. Notably, the unique DOM components specific to each ecosystem increased during peak fluxes in the forest but decreased in the grassland. We suggest that an overall higher molecular richness and the broader functional metabolic potentials in grassland may account for its relatively greater DOM stability compared to the forest during peak snowmelt events. [ABSTRACT FROM AUTHOR]

The primary objective of this study is to evaluate soil evaporation in arid regions using a minimal set of readily accessible parameters, which are represented through a nomogram. This work explores the relationships between soil evaporation, soil water deficit, and air temperature. Evaporation is a critical factor influencing the soil water regime. Irrigation artificially adjusts soil moisture to maintain it within optimal limits for vegetation. This regulation can only be effectively managed if the principles of soil-water balance are thoroughly understood. In arid and semi-arid regions, where water quality is often poor (high salinity), prolonged excessive irrigation can lead to soil salinization, thereby reducing agricultural productivity. In this study, ten lysimeters were used to measure soil evaporation at different levels of soil water saturation. The highest evaporation rate was recorded in fully saturated soil, peaking at 548 mm. This rate decreased as the soil water saturation decreased. Therefore, a good knowledge of the evaporation value is necessary to establish appropriate irrigation and soil leaching rates and consequently, an adequate water balance. [ABSTRACT FROM AUTHOR]

Lysimeters have been used to obtain accurate information for developing calibrating, and validating crop evapotranspiration and crop coefficients for many plants and crops. Lysimeters are also an unique equipment for studying the transport of solutes when saline waters are used, and therefore, for assessing alkalization and salinization hazards. Three main types of lysimeters are used: constatnt water-table lysimeters, drainage lysimeters, and weighing lysimeters. The weighing lysimeters provide scientist the basic information for research related to the evapotranspiration, and they are commonly divided into two types, continuous weighing and intermittent weighing. Lysimeters are foremost devices, typically tanks or containers, that define a specific boundary to contain soil water and permit measurement of either the soil-water balance or the volume of water percolating vertically and its quality. The limitations are expense which depends on design, variable experimental conditions such as climatic/environmental factors which are usually not controlled, the spatial variability is normally less, they are not appropriate for every plant species and even every soil type. The main goal of lysimeter is defining the crop coefficient (Kc) which used to convert Etr to equivalent crop ET (Etc) values, and determining agronomical parameters of crops which are planted on the field of lysimeter. All weather data like air temperature, humidity, solar radiation, and potential evaporation should be obtained onsite, and the frequency and time of measurements should be at least daily. For crop products, the management such as fertilization, sowing tillage, seed bed preparation, and harvest of the lysimeter including its surrounding area is carried out on the basis of good agricultural practice. it may be required to complement natural precipitation by irrigation. The main purpose of this literature review is to give a brief summary about lysimeters, and survey the impacts of lysimeter studies and crops production. The information provides is obtained from randomized control experiments, review articles, and analytical studies and observations which were gathered from numerous literature sources such as Scopus, PubMed, Google Scholar,and Science Direct.

Evapotranspiration plays a key role in the terrestrial water cycle, climate extremes, and vegetation functioning. However, the understanding of spatio-temporal variability of evapotranspiration is limited by a lack of measurement techniques that are low cost and that can be applied anywhere at any time. Here we investigate the estimation of evapotranspiration and land surface energy-balance partitioning by only using observations made by smartphone sensors. Individual variables known to effect evapotranspiration as measured by smartphone sensors generally showed a high correlation with routine observations during a multiday field test. In combination with a simple multivariate regression model fitted on observed evapotranspiration, the smartphone observations had a mean RMSE of 0.10 and 0.05 mm h -1 during validation against lysimeter and eddy covariance observations, respectively. This is comparable to an error of 0.08 mm h -1 that is associated with estimating the eddy covariance ET from the lysimeter or vice versa. The results suggests that smartphone-based ET monitoring could provide a realistic and low-cost alternative for real-time ET estimation in the field. [ABSTRACT FROM AUTHOR]

Transpiration efficiency (TE), the biomass produced per unit of water transpired, is a key trait for crop performance under limited water. As water becomes scarce, increasing TE would contribute to increase crop drought tolerance. This study is a first step to explore pearl millet genotypic variability for TE on a large and representative diversity panel. We analyzed TE on 537 pearl millet genotypes, including inbred lines, test-cross hybrids, and hybrids bred for different agroecological zones. Three lysimeter trials were conducted in 2012, 2013 and 2015, to assess TE both under well-watered and terminal-water stress conditions. We recorded grain yield to assess its relationship with TE. Up to two-fold variation for TE was observed over the accessions used. Mean TE varied between inbred and testcross hybrids, across years and was slightly higher under water stress. TE also differed among hybrids developed for three agroecological zones, being higher in hybrids bred for the wetter zone, underlining the importance of selecting germplasm according to the target area. Environmental conditions triggered large Genotype x Environment (GxE) interactions, although TE showed some high heritability. Transpiration efficiency was the second contributor to grain yield after harvest index, highlighting the importance of integrating it into pearl millet breeding programs. Future research on TE in pearl millet should focus (i) on investigating the causes of its plasticity i.e. the GxE interaction (ii) on studying its genetic basis and its association with other important physiological traits. [ABSTRACT FROM AUTHOR]

The Haihe Plain in China is situated in the world's largest groundwater funnel area, with per capita water resources far below the internationally recognized "extremely water-scarce" standard. To address the issue of water shortage in summer maize-planting areas of the Haihe Plain, we conducted research on the variation of summer maize evapotranspiration using a medium-sized lysimeter. This study aims to provide technical support for water-saving irrigation in summer maize fields. Through path analysis, direct and indirect influencing factors affecting the evapotranspiration of summer maize fields were determined. The results showed that the cumulative evapotranspiration of bare ground and farmland during the entire growth period of summer maize was 173.57 mm and 382.97 mm, respectively, with evapotranspiration intensities of 1.52 mm/d and 3.36 mm/d, respectively. Evapotranspiration during the maturity stage of summer maize was the least, accounting for only 1.82% of total evapotranspiration during the entire growth period. The period from the jointing to milk-ripening stage is when evapotranspiration in maize fields is at its highest. During this period, evapotranspiration in maize fields amounted to 265.58 mm, accounting for 69.35% of total evapotranspiration. The evapotranspiration intensity was 3.59 mm/day, which is 1.34 times higher than that of bare soil. The evapotranspiration intensities during each growth stage were ranked as jointing stage > tasseling-silking stage > seedling stage > milk maturity stage > maturity stage. The daily evapotranspiration of summer maize fields showed a "unimodal" curve with low values in the morning and evening, and high values at noon. Path analysis indicated that daily radiation and maximum daily temperature had the greatest impact on the evapotranspiration of maize fields, with the direct effect of maximum daily temperature being restrictive and the indirect effect being promotive, resulting in an overall promotive effect. [ABSTRACT FROM AUTHOR]

Introduction Agricultural water management studies require accurate information on actual evapotranspiration. This information must have sufficient spatial detail to allow analysis on the farm or basin level (Sanchez et al., 2008). The methods used to estimate evapotranspiration are grouped into two main groups, which include direct methods and indirect or computational methods (Alizade and Kamali, 2007). Basics of the indirect methods are based on the relationship between meteorological parameters, which impedes the use of these data with a lack or impairment. On the other hand, this information is a point specific to meteorological stations, and their regional estimates are another problem of uncertainty of their own. To this end, the use of remote sensing technology can be a suitable approach to address these constraints. Real evapotranspiration can be estimated by satellite imagery that has short and long wavelengths and is estimated using surface energy equations (Chihda et al., 2010). Examples of such algorithms include SEBAL (Bastiaanssen et al., 1998 Bastiaanssen, 2000;), METRIC (Allen et al., 2007), SEBS (Su, 2002). Among the above mentioned algorithms, energy billing algorithms have been used (Bagheriharooni et al., 2013; Teixeira et al., 2009). Among the factors of superiority of the SEBAL algorithm, in comparison with other remote sensing algorithms, is a satellite imagery analysis algorithm based on physical principles and uses satellite simulation and requires minimum meteorological information from ground measurements or air models (Bastiaanssen et al., 2002). Methodology In this research, 24 images from Landsat 8 satellite and 60 Sentinel 2 satellite images were used during growth period of sugarcane in 2016 and 2017, respectively (from May 28 to October 17 of each mentioned year). The study area is located in the Amir Kabir unit of Sugarcane Industry in the southern province of Khuzestan, one of the seven sugar cane cultivars and industries with local coordinates of 48 ° 16'49'E and 31 ° 2' 2'N. Amir Kabir Cultivation & Industry is located at Km 45 of Ahvaz - Khorramshahr Road, which is located south of Mirza Kuchak Khan's cultivation and is located in the east of Karoon's River. The total area of this farm was 15,000 hectares and its net area was 12,000 hectares, divided into several 25 hectares. The required meteorological information was extracted from the Amir Kabir Crop Production and Meteorological Station. This information includes: wind speed, sunshine hours, maximum and minimum temperatures, and rainfall. Results and Discussion The main objective of this study was to estimate the actual evapotranspiration of the sugarcane by using Landsat 8, Sentinel 2 and SEBAL algorithm. Finally, the results were compared with lysimetric data and analyzed. For statistical analysis of the results, the absolute difference indices and relative differences were used. In order to estimate evapotranspiration, as mentioned earlier, it was necessary to obtain the values of pure radiation and the heat flux for hot and cold pixels. The results are presented in Table 1, by separation of the evapotranspiration estimation method and the date of the images. Table (1) shows the potential evapotranspiration using the Taylor Presley method and the maximum values estimated by the SEBAL algorithm for Amir Kabir cultivation and industry. According to Table 1 the evapotranspiration rate calculated using the Taylor-Presley method is not significantly different from the evapotranspiration calculated by the SEBAL algorithm. In general, it can be stated that the method of using Landsat 8 and Sentinel 2 satellite images can calculate the amount of canopies evapotranspiration and transpiration with a small error value. the lysimeter gives the actual amount of evaporation and transpiration, by comparing the values of evapotranspiration calculated by the SEBAL algorithm and the values provided by the Lysimeter, the rate of error estimation indices represents less values. Therefore, according to Table (1), Sahbal algorithm is a suitable method for estimating the amount of evapotranspiration of cane sugar. ... The results showed that, despite the fact that the Sentinel 2 satellite does not have thermal bands, it is possible to calculate the actual evapotranspiration using the SEBAL algorithm by combining the satellite images with the Landsat satellite. Landsat satellite images are also challenging to estimate the water requirement, but according to the calculated indices, there is no significant difference with the lysimetric data. Compared to the combination of images, which have a precise accuracy in order to cover the time lag of Landsat 8 and Sentinel 2. Conclusions The SEBAL algorithm solves the energy balance equation to calculate the actual evapotranspiration of the plant, and the calculated parameters such as surface temperature, NDVI are defined in a certain range and are acceptable. The calculations showed that the results were consistent with the acceptable limits stated in the sources and statistics, and they confirmed this algorithm. Also, in comparison with the Taylor-Presley method, it was observed that SEBAL has calculated the actual evapotranspiration with acceptable results, which is also the reason for this method in calculating evapotranspiration. Due to errors in collecting climatic data such as wind speed, air temperature, solar radiation, day time duration, humidity, and also lack of calibration of coefficients such as coefficient of evaporation pan, plant coefficients for estimating evapotranspiration in many common error methods has it. In this regard, it is possible to consider new methods, such as the use of satellite imagery, to calculate the evapotranspiration of the plant for a wide range of plains as well as a point scale. It is obvious that by using suitable spatial resolution with homogeneity of the field farms and at appropriate time intervals, it is possible to plot the actual evapotranspiration of the plant for each region during the growing season. [ABSTRACT FROM AUTHOR]

Manure application performed in autumn requires regulation due to the risk of nitrogen (N) leaching during winter. On the other hand, application of manure in spring can pose some practical problems depending on the risk for N immobilization and the difficulty in ploughing heavy clay soils during this time of year. The risk for leaching is likely to differ between different soil texture and manure characteristics. In this study, we sought to estimate the risk for nitrogen leaching depending on the carbon/nitrogen ratio (C/N) of the manure, time for manure application, and soil type. We combined 3-year lysimeter experiments with 2-year field plot experiments and laboratory soil incubations and compared results with those from an empirical model. We compared effects of manure application on two soils (silty clay and loamy sand) and solid manures with different representing C/N ratios. In incubations, only manure with a C/N-ratio below 14 contributed with significant amounts of leachable N during the first months after application. In the lysimeter study, N leaching was unaffected by the timing of the application of the manure with C/N-ratio 18. However, regarding manure with C/N-ratio 10, N leaching was elevated with 10–15 kg N per ha after manure application in October compared to November and March on both soil types. The mineral N analyses from soil profiles in the field experiments showed a similar pattern, however, the increase was higher on the loamy sand compared to the silty clay. The ammonia emissions did not differ between manure types, but were on average 24% of applied NH4-N after application in October when air temperature was on average 12°C compared to only 3% of applied NH4-N in November and March when air temperature was on average 5°C. Similar to lysimeter results, the modelled N leaching was higher the earlier the manure application occurred in autumn. However, the model also predicted increased leaching for the manure with a high C/N-ratio, and a smaller effect on leaching on clay soil. Considering this, the model calculations overestimated the leaching effects from manure with a high C/N-ratio and underestimated the leaching effects on clay soil.

Snowfall/cover and snowmelt are essential determinants of winter soil processes/events that may force the biogeochemical dynamics of soils in temperate regions. Increasing variability of the European hydroclimate is expected to lead to more frequent intermittent warm periods, which cause snowmelt during winter and rapidly mobilize large amounts of dissolved organic matter (DOM). This study, conducted at the Hainich Critical Zone Exploratory in Germany, seeks to address a significant gap in understanding the molecular impacts of snowmelt-induced DOM flows and their ability to alter soil ecosystems rapidly. During two snowmelt events between January and March 2021, we observed that DOM concentration and composition varied more in forest soil seepage than in grassland soil seepage. Forest seepage showed a pronounced DOM flux peak and synchronous increases in the relative abundances of aromatic DOM components, indicating surface-derived transport of plant litter carbon. In the grassland, however, peak DOM fluxes were characterized by a marked increase in nitrogen-containing (N-containing) DOM components, indicating a predominance of microbial carbon. Notably, the unique DOM components specific to each ecosystem increased during peak fluxes in the forest but decreased in the grassland. We suggest that an overall higher molecular richness and the broader functional metabolic potentials in grassland may account for its relatively greater DOM stability compared to the forest during peak snowmelt events.

ABSTRACT The estimation of evapotranspiration (ET) and crop water requirements are crucial for the proper management and allocation of water resources in terms of quantity, quality, and timeliness. Therefore, remote sensing estimation of ET using the SEBAL algorithm (Surface Energy Balance Algorithm for Land) can provide spatio-temporal, non-punctual data, unlike traditional calculations relying on the nearest meteorological station. This research analyzed ET using SEBAL, based on ten Landsat 8 satellite images processed with a program developed in the Model Builder of ArcGis® version 10.2. The analysis was conducted during the vegetative period of starchy corn from May to October 2016. Validation of the results happened with a drainage lysimeter installed in a monitoring plot. Additionally, the statistical indices - such as percentage relative error (PRE) (0,09), root mean square error (RMSE) (0,30), R2 (0,92), and Nash-Sutcliffe efficiency (NASH) (0,91) - indicated a good correlation of ET for starchy corn in the central highlands of Peru. The ET identified at ten monitoring points ranged from 1,05 to 7,79 mm d-1.

Per- and poly-fluoroalkyl substances (PFAS) are a group of organo-fluorine compounds that have been broadly used in consumer and industrial products spanning virtually all sectors. They can be found as surfactants, coatings and liners, polymer additives, fire retardants, adhesives, and many more. The chemical stability of the carbon fluorine bond and amphiphilic nature of PFAS result in their persistence and mobility in the environment via soil porewater, surface water and groundwater, with potential for adverse effects on the environment and human health. There is an emergent and increasing requirement for fast, low-cost, robust, and portable methods to detect PFAS, especially in the field. There may be thousands of PFAS compounds present in soil and water at extremely low concentration (0.01–250 ppb) that require measurement, and traditional technologies for continuous environmental sensing are challenged due to the complexity of soil chemistry. This paper presents a comprehensive review of potentially rapid PFAS measurement methods, focused on techniques for representative sampling of PFAS in porewater from contaminated soil, and approaches for pre-treatment of porewater samples to eliminate these interferences to be ready for PFAS-detecting sensors. The review discusses selectivity, a key factor underlying pre-treatment and sensing performance, and explores the interactions between PFAS and various sensors. PFAS chemical nano-sensors discussed are categorized in terms of the detection mechanism (electrochemical and optical). This review aims to provide guidance and outline the current challenges and implications for future routine PFAS sensing linked to soil porewater collection, to achieve more selective and effective PFAS sensors.

A simple weighable lysimeter was designed, constructed, and calibrated for measuring the water requirements and crop coefficients of shallow-rooted crops. It has a portable weighing mechanism to quantify changes in soil moisture content. The weighing mechanism consists of a horizontal steel bar, a hydraulic car jack, both ends hooked vertical steel bars, a stand, and a digital weighing balance. As the lysimeter's inner tank, a plastic drum with a 55 cm diameter that yields 0.24 m2 of internal area was used. A performance test was conducted, and a rating curve was developed at the beginning of the growing seasons in 2023 and 2024 to evaluate the sensitivity of the weighing mechanism in determining crop water use. Linearity, repeatability, and measurement uncertainty tests were conducted. The linearity error was ±0.04 kg and ±0.03 kg for the years 2023 and 2024, respectively, which is within the allowable limit. The weighing system repeats the measurement perfectly with no error (repeatability error was zero). The combined uncertainty of the measurements was 0.023 kg, representing the cumulative effect of individual errors. The lysimeter weighing system is capable of detecting variations in mass as small as 0.2 mm of moisture content. Therefore, the developed lysimeter can be used to determine water requirements and crop coefficients of shallow-rooted crops for the design and management of irrigation in data-scarce areas of Ethiopia.

We developed a set of two precision, small-scale, water balance lysimeters to provide accurate measurements of bare soil evaporation. Each lysimeter comprises a soil tank, a balance assembly with load cell, a wicking drainage system, and a stilling well to measure drained water. Fiberglass wicks installed at the bottom of the soil tanks provide −60 cm of tension to the base of the soil column, and soil water drainage is quantified to close the water balance within the lysimeter. The calibrated lysimeters return mass changes with uncertainties ranging from 3 to 8 g, corresponding to uncertainties of 0.02–0.05 mm of water. Installed at a semi-arid site in northern Nevada, the two lysimeters are filled with uniform construction sand and silt loam. Over a six-month pilot observation period, bare soil evaporation rates of 0.19 and 0.40 mm/day were measured for the construction sand and silt loam, respectively, which is consistent with meteorological data and models of potential evapotranspiration at the site. The design of the lysimeter can be adapted to specific research goals or site restrictions, and these instruments can contribute significantly to our ability to close the soil water balance. [ABSTRACT FROM AUTHOR]

Introduction: Despite various efforts to reduce nitrogen leaching from agricultural land, the permissible nitrate concentrations in groundwater have often been exceeded in the past. Intensive farming is often seen as the cause of the deterioration in water quality. Therefore, the present lysimeter study aimed to quantify nitrogen (N) leaching at different N fertilization levels for the agricultural land use systems of arable land and grassland to derive suitable management measures for improving groundwater quality. Methods: The effects of three different of mineral fertilization treatments (50%, 100%, and 150%) in arable land and grassland use on four distinct soil types (loamy sand, sand, loam, loess) concerning seepage formation, nitrogen concentrations, nitrogen loads, drymatter yields and nitrogen balances were tested. The study was conducted at the lysimeter facility of the Helmholtz Centre of Environmental Research - UFZ at Falkenberg (northeast Germany). Twenty-four non-weighable lysimeters with a surface area of 1 m² and a depth of 1.25 m were managed as grassland and arable land with three different fertilization treatments since 1985. Results and Discussion: For arable land use, N leaching differed between the studied soil types, with the highest N loads from the sand (36.6 kg ha-1 yr-1) and loamy sand (30.7 kg ha-1 yr-1) and the lowest N loads fromloess (12.1 kg ha-1 yr-1) and loam soil (13.1 kg ha-1 yr-1). In contrast to grassland use, a reduction of N fertilization level by 50 % did not result in reduced N leaching for arable land, whereas a maximal 29% reduced dry matter yields was observed. An increase of N fertilization by 50 % did not cause significant enhanced N leaching at arable land use. Soil-and management-related factors (soil type, texture, soil tillage, crop rotation, and others)mask the effect of increased N fertilization rates in arable land using lysimeters. For arable land use, a reduction of N fertilizer levels as the only measure was insufficient to reduce NO3- leaching, and other strategies besides N fertilization levels are required to improve groundwater quality. Measures should be targeted to reduce N losses by mineralization processes. [ABSTRACT FROM AUTHOR]

Determining the evapotranspiration (ET) of cotton as a water-intensive crop is crucial for effective irrigation planning and water management, especially in regions like Sindh province, Pakistan, where shallow groundwater table depths (WTDs) are prevalent. Despite the importance of cotton, a major cash crop in Sindh, previous studies on ET were conducted decades ago and may no longer be reliable due to ongoing climate change and the introduction of new crop varieties. Thus, we quantified cotton ET across two cropping seasons and at various WTDs (0.45, 0.60, 0.75, 1.50, 2.25, and 2.75 m). The experimental study was based on the data procured from 12 mini lysimeters and 12 large lysimeters for two years (2018 and 2019) and at two soil series. The findings revealed that cotton ET ranged from 1332 to 1437, 1114–1202, 988–1075, 781–821, 690–733, and 637–683 mm at WTDs of 0.45, 0.60, 0.75, 1.50, 2.25, and 2.75 m, respectively. WTDs from 0.45 to 0.75 m fulfilled 94–96 % of cotton ET through groundwater (GW) contribution in Sultanpur soil (silt loam) and 93–97 % in Miani soil (silty clay loam). At 1.50–2.75 m WTDs, irrigation water requirements (excluding rainfall and leaching) were 63–88 % in Sultanpur soil and 67–89 % in Miani soil. The highest yield was observed at a 1.50 m WTD, while the highest water use efficiency was identified at a 2.25 m WTD. However, soil salinity increased by 60–80 %, resulting in a 40–60 % lower cotton yield at 0.45–0.75 m WTD. Therefore, periodic flushing of salts is necessary to utilize shallow WTDs effectively. Considering GW contribution to ET when allocating water for irrigation channels and devising irrigation schedules is crucial. This approach can lead to water savings, prevent land from becoming waterlogged and saline, manage the groundwater table, and reduce the need for drainage channels and labor force for their preparation.

Excessive nitrogen (N) fertilization and irrigation prevail in irrigated agriculture worldwide. However, little information is available that systematically evaluates grain yield, plant N uptake, residual soil NO3−-N (RSN), and N leaching under different irrigation–N regimes in an irrigated maize production system. To address such agronomic and environmental issues, a 6-year in situ lysimeter field trial was conducted in the Hetao Irrigation District of China with five treatments: 1) conventional irrigation (3,900 m3/ha) and local farmer fertilizer N rate (490 kg ha−1) (CON); 2) conventional irrigation and the recommended fertilizer N rate (420 kg ha−1) (RN); 3) deficit irrigation (2,730 m3/ha) and the recommended fertilizer N rate (SRN); 4) deficit irrigation and the recommended fertilizer N rate (with ∼ 10 % organic fertilizer N substitution) (SMN); and 5) conventional irrigation and controlled-release N fertilizer (270 kg ha−1) (CRF). Maize yield was not significantly different across treatments in 2015–2020. Averaged across years, SMN, SRN, and CRF significantly increased plant N uptake compared with that in CON by 28.84 %, 19.15 %, and 17.53 %, respectively. Residual soil NO3−-N at 0–90 cm was ranked as SRN > CON ≈ SMN > RN > CRF, whereas cumulative N in leachate from 2015–2020 (Nloss) in CON was 86.2 % to 187.1 % higher than that in other treatments. The Nloss in SRN was equivalent to that in RN and SMN, but Nloss in SMN decreased significantly compared with that in RN, indicating additive benefits of deficit irrigation and organic input on reducing N leaching. Structural equation modelling revealed that irrigation had greater effects on plant N uptake than those of fertilization, whereas N rate had a greater total effect on N leaching than that of irrigation. Overall, rampant excessive irrigation and N fertilization by farmers can be substantially reduced while maintaining grain yield and mitigating N leaching loss, with further benefits gained by applying controlled-release N fertilizer and manure in irrigated maize production.

Purpose: to study the dynamics of moisture in soils on the drainage layer during drip irrigation to save water resources and ensure uniform watering of crops using moisture contours. Materials and methods. The study is based on the theory of moisture transfer under the influence of drip irrigation on soil. Moisture contours were studied in laboratory conditions using a soil lysimeter, which was used to model the geological cross-section of the irrigated area, represented by alluvial meadow soils formed on pebbles. The pebble layer thickness was assumed to be up to 3 m. A regression analysis of moisture movement was carried out, and a mathematical model describing the nature of its movement on the drainage layer was obtained. The estimated volume of wet soil was defined on the basis of moisture contours as a result of calculating the volume of the formed lathe object using cartograms for each hour of irrigation. Results. Data on the moisture distribution in soil profile according to irrigation hours, presented on cartograms constructed using a personal computer, were obtained. The contours with the same humidity – isolines on which the humidity was displayed: 5; 10; 40 % are highlighted on the cartograms. It has been determined that water at an emitter discharge of 2.5 l/h reaches the drainage layer 4 hours after the beginning of irrigation. The graph for moisture distribution in soil volume by hour, reflecting the dynamics of water distribution supplied from an emitter with a constant discharge over 10 hours of irrigation has been constructed. Conclusion. The dynamics of moisture distribution during drip irrigation in soils located on a drainage bed was studied. Under experimental conditions, when crop irrigation lasts for more than 8 hours, an ineffective excess of irrigation rate and an increase in the design capacity of the drip irrigation system are observed.

The upward movement of water through capillary rise from the shallow water-table (1–1.5 m) to the root zone (0.4–0.6 m) is an important incoming flux in the soil system. UPFLOW is a specialized model for determining capillary rise, which is a simple model with a small amount of input data. This research was conducted to assess the efficiency of the UPFLOW model in the simulation of capillary rise in shallow water-table conditions, based on the observed capillary rise using a lysimeter in the agro-industry of Amirkabir, Khuzestan. The input data of the model include: crop(root-water uptake rate at different sections of root zone, crop cover type, crop coefficient), soil(number of soil layers and their thickness, mean soil-water content of the profile, anaerobiosis point of the soil, saturated hydraulic conductivity of the soil profile), weather(maximum and minimum temperature, solar radiation, wind speed, and relative humidity, ET0) and water-table(depth to water-table from the soil surface, salt content of the groundwater) were measured. Then, the capillary rise was calculated for each month during the stages of sugarcane growth. The performance of this model was evaluated by the statistical indices including determination coefficient (R2), mean absolute error (MAE), root mean square error (RMSE), relative error (RE), and model efficiency (EF). The results of the field measurement showed that the highest amount of capillary rise (1.6 mm) was observed in July, with the maximum evapotranspiration (400 mm) and the maximum growth of sugarcane. The lowest value (0 mm) also was observed in the months when sugarcane growth stopped, i.e., November, December, January, and February. The results of this research have shown that the UPFLOW model in the studied area has not shown suitable efficiency (based on statistical indicators) in the simulation of the upward flow in specific conditions of water-table, crop, soil, climate, and management measures (R2:0.23, MAE:8.71, RMSE:9.10, RE:180.50, EF: -136.40). Therefore, this model, in shallow water-table conditions, to accurately estimate capillary rise, requires comprehensive evaluations of various effective factors and, if possible, to modify and adjust this model in this area.

Water deficit is the main limiting factor in rainfed agricultural production, negatively affecting germination and vegetative development. The objectives of this work were to characterize inbred lines for drought tolerance, to identify the most important root and shoot morphological traits for discriminating genotypes, to compare the efficiency of identifying contrasting inbred lines using uni- and multivariate methods, and to evaluate the effectiveness of identifying drought-tolerant genotypes at seedling and vegetative stages. We assessed 28 popcorn inbred lines and three maize single crosses, two drought-tolerant and one drought-sensitive. At the seedling stage, drought was induced on germitest paper moistened with polyethylene glycol 6000. At the vegetative stage, we applied water stress using lysimeters. We measured root and shoot morphological traits under water stress and no stress and processed the relative values. Uni- and multivariate methods, alone or in combination, were equally efficient for identifying contrasting inbred lines for drought tolerance. The confidence interval and Dunnett’s test worked very well when contrasting controls were included. Principal component analysis allowed to discriminate genotypes and identify the most important traits for discriminating them. At the seedling stage, inbred line 22-1824-2 was the most drought-tolerant and 22-1877-3 the most sensitive. At the vegetative stage, inbred lines 22-1920-1 and 22-1867-4 were the most tolerant and 22-1860-5 was the most sensitive. Root length, volume, dry weight, and surface area, as well as water content, were the most important traits for discriminating genotypes. Due to distinct tolerance mechanisms, drought tolerance should be assessed at both stages.

As urbanization intensifies environmental challenges in contemporary cities, widespread green roof installations emerge as a potential solution. This study explores irrigating tall fescue (Festuca arundinacea Schreb.) turfgrass with saline water in extensive green roof systems, aiming to conserve freshwater resources. The objectives include determining the period of saline water tolerance and identifying the leachate electrical conductivity threshold affecting tall fescue's green coverage. This greenhouse study comprised 24 lysimeters equipped with extensive green roof layering. Treatments included three NaCl irrigation solutions with an electrical conductivity of 3 dS m−1, 6 dS m−1, and 9 dS m−1, while tap water served as the control. Additionally, irrigation treatments were applied at two different regimes, resulting in an average leaching fraction of 0.3 for the low irrigation regime and 0.5 for the high irrigation regime. Tall fescue's tolerance to saline water was evaluated through the determination of green turf cover (GTC) as well as the clipping dry weight and the leachate electrical conductivity (ECL) draining from the lysimeters. It was found that tall fescue turfgrass growing in extensive green roof systems can tolerate irrigation with water of electrical conductivity up to 9 dS m−1 for extended periods, approximating three months, without GTC declining below 90%, provided that a minimum leaching of 30% is maintained. Furthermore, irrigating with water at 9 dS m−1 resulted in a 24.5% reduction in cumulative clipping dry weight over the four-month study period. The regression analysis between GTC and ECL highlighted a substantial decline in GTC when ECL surpassed the critical threshold of 12.5 dS m−1. [ABSTRACT FROM AUTHOR]

Soil–hydrophysical research substantiating the mathematical models of water movement, taking into account the soil heterogeneity, due to the vertical change in texture, is considered. The vertical movement of water on large-size lysimeters of the Federal Scientific Center of Agroecology of the Russian Academy of Sciences (Volgograd) was studied. The influence of statistical heterogeneity of hydrophysical parameters of lysimeter substrates was studied on models of water transfer dynamics and formation of gravitational runoff developed in the HYDRUS-1D software package. The change in texture along the vertical profile of the lysimeters and the related variability of the main hydrophysical characteristic or water retention curve (WRC) were taken into account. The textural heterogeneity of the substrates was estimated by the scaling method, according to the scale factors of the WRC parameters, assuming a normal probability distribution of the logarithms of the pore space capillary radii between soil particles. The effect of texture on water holding capacity, boundary and initial conditions, intensity of gravitational runoff and cumulative accumulation of water were studied. [ABSTRACT FROM AUTHOR]

The upward movement of water through capillary rise from the shallow watertable (1-1.5 m) to the root zone (0.4-0.6 m) is an important incoming flux in the soil system. UPFLOW is a specialized model for determining capillary rise, which is a simple model with a small amount of input data. This research was conducted to assess the efficiency of the UPFLOW model in the simulation of capillary rise in shallow water-table conditions, based on the observed capillary rise using a lysimeter in the agro-industry of Amirkabir, Khuzestan. The input data of the model include: crop(root-water uptake rate at different sections of root zone, crop cover type, crop coefficient), soil(number of soil layers and their thickness, mean soil-water content of the profile, anaerobiosis point of the soil, saturated hydraulic conductivity of the soil profile), weather(maximum and minimum temperature, solar radiation, wind speed, and relative humidity, ET0) and water-table(depth to water-table from the soil surface, salt content of the groundwater) were measured. Then, the capillary rise was calculated for each month during the stages of sugarcane growth. The performance of this model was evaluated by the statistical indices including determination coefficient (R²), mean absolute error (MAE), root mean square error (RMSE), relative error (RE), and model efficiency (EF). The results of the field measurement showed that the highest amount of capillary rise (1.6 mm) was observed in July, with the maximum evapotranspiration (400 mm) and the maximum growth of sugarcane. The lowest value (0 mm) also was observed in the months when sugarcane growth stopped, i.e., November, December, January, and February. The results of this research have shown that the UPFLOW model in the studied area has not shown suitable efficiency (based on statistical indicators) in the simulation of the upward flow in specific conditions of water-table, crop, soil, climate, and management measures (R²:0.23, MAE:8.71, RMSE:9.10, RE:180.50, EF: -136.40). Therefore, this model, in shallow water-table conditions, to accurately estimate capillary rise, requires comprehensive evaluations of various effective factors and, if possible, to modify and adjust this model in this area. [ABSTRACT FROM AUTHOR]

The construction of modern lysimeters with a precise weighing system made it possible to achieve an unprecedented accuracy of precipitation measurement. This study compares two methods of measuring precipitation in the conditions of the humid continental climate of the Eastern Slovakian Lowland (Slovakia): measurement using a standard tipping-bucket rain gauge vs. precision weighable lysimeter. Data from the lysimeter were used as a reference measurement. The comparison period lasted four years (2019–2022). Only liquid rainfall was compared. The rain gauge was found to underestimate precipitation compared to the lysimeter. Cumulative precipitation for the entire monitored period captured by the rain gauge was 2.8% lower compared to lysimeter measurements. When comparing hourly and daily totals of precipitation and precipitation events, a very high degree of agreement was detected (r2 > 0.99; RMSE from 0.22 to 0.51 mm h–1). A comparison based on precipitation intensity showed a decreasing trend in measurement accuracy with increasing precipitation intensity. This tendency has an exponential course. With increasing intensity of precipitation, increasing intensity of wind was also recorded. In order to correct measurement errors, simple correction method was proposed, which helped to partially eliminate the inaccuracies of the rain gauge measurement. [ABSTRACT FROM AUTHOR]

IntroductionDespite various efforts to reduce nitrogen leaching from agricultural land, the permissible nitrate concentrations in groundwater have often been exceeded in the past. Intensive farming is often seen as the cause of the deterioration in water quality. Therefore, the present lysimeter study aimed to quantify nitrogen (N) leaching at different N fertilization levels for the agricultural land use systems of arable land and grassland to derive suitable management measures for improving groundwater quality.MethodsThe effects of three different of mineral fertilization treatments (50%, 100%, and 150%) in arable land and grassland use on four distinct soil types (loamy sand, sand, loam, loess) concerning seepage formation, nitrogen concentrations, nitrogen loads, dry matter yields and nitrogen balances were tested. The study was conducted at the lysimeter facility of the Helmholtz Centre of Environmental Research – UFZ at Falkenberg (northeast Germany). Twenty-four non-weighable lysimeters with a surface area of 1 m² and a depth of 1.25 m were managed as grassland and arable land with three different fertilization treatments since 1985.Results and DiscussionFor arable land use, N leaching differed between the studied soil types, with the highest N loads from the sand (36.6 kg ha–1 yr–1 ) and loamy sand (30.7 kg ha–1 yr–1 ) and the lowest N loads from loess (12.1 kg ha–1 yr–1) and loam soil (13.1 kg ha–1 yr–1). In contrast to grassland use, a reduction of N fertilization level by 50 % did not result in reduced N leaching for arable land, whereas a maximal 29% reduced dry matter yields was observed. An increase of N fertilization by 50 % did not cause significant enhanced N leaching at arable land use. Soil-and management-related factors (soil type, texture, soil tillage, crop rotation, and others) mask the effect of increased N fertilization rates in arable land using lysimeters. For arable land use, a reduction of N fertilizer levels as the only measure was insufficient to reduce NO3– leaching, and other strategies besides N fertilization levels are required to improve groundwater quality. Measures should be targeted to reduce N losses by mineralization processes.

The Longdong Loess Plateau is an important rainfed agricultural area in China.It is of great significance to study the differences of land surface processes under different farmland for understanding the regional land-atmosphere interaction.Based on the farmland micrometeorological and lysimeters observation data of Qingyang City， Gansu Province from June 2021 to May 2022， this paper analyzed the differences in microclimate and evapotranspiration characteristics of three different crops： apple， corn， and wheat； combined with correlation analysis and sensitivity analysis， the main influencing factors of evapotranspiration from the underlying surface of different crops were discussed.The results showed that： （1） The temperature and land-air temperature difference in the apple field were smaller during the growing period； the relative humidity of corn field was higher than that of wheat field， especially in the canopy； the surface albedo of corn field was basically lower throughout the year， but it increased in May due to covering with mulch film， and its annual average net radiation was significantly lower than that of the apple field and wheat field； （2） The daily variation of evapotranspiration basically followed the mid-growth stage > the early growth stage > the maturity stage， the evapotranspiration of corn was the largest in the mid-growth period， reaching a maximum of 4.9 mm·d-1， and the annual daily evapotranspiration of wheat field was less than 3 mm·d-1.during the whole growth period， the change of daily evapotranspiration of apple field was the most， while that of wheat field was relatively stable； （3）Net radiation was the main meteorological driving factor for evapotranspiration change in apple field and corn field during the growing period， but it had relatively little effect in wheat field； the sensitivity of evapotranspiration to saturated water vapor pressure difference in the growing period of the three places was smaller than that in the non-growing period.

Introduction and Objective Due to droughts occurred in recent years, available water resources in southern basins and watersheds of Iran especially those are in Hormozgan Province has been drastically decreased which may not only change their ecosystem but also make serious problem for the country’s food security. In addition to find new water resources, effective use of available water is the best choice to tackle water deficit which in turn, requires accurate estimation of evapotranspiration or water needs of plants. Crop evapotranspiration is usually calculated using the two-step FAO method. In this method, first the reference crop evapotranspiration (ET0), representing effect of weather on crop evapotranspiration is estimated by models using weather variables and then, multiplied by crop coefficient (Kc) which reflects crop characteristics on evapotranspiration. A review on the research conducted around the world revealed that each model may have different accuracies and performances at different watersheds or locations. Subsequently, using these models without testing their accuracy and relevance at each watershed may increase error in estimating (ET0) and hence crop water requirements which may complicate any planning for the watershed in the future. Therefore, this research was conducted to evaluate the accuracy and performance of the FAO proposed models at Haji Abad watershed of Hormozgan Province.Materials and Methods In this research which was conducted in Haji Abad watershed of Hormozgan for four years, reference crop(grass) evapotranspiration was measured weekly using a drainable lysimeter. In the first year, a large square drainable lysimeter (3 m wide ×3 m long × 1.9 m tall) was installed in the center of a 2-ha agricultural field which was representative of the watershed. In the next third years, grass (Cynodon dactylon L.) was grown inside the lysimeter and in the 900 m2 surrounding field. At full cover and when grass height reached 8 cm, evapotranspiration from grass inside the lysimeter was measured weekly by the water balance method. Reference crop evapotranspiration was also estimated using the FAO models: Adjusted penman and Blaney- Criddle, Radiation, Evaporation pan and Penman-Monteith. The estimated (ET0) values from the FAO models were compared with the data measured from lysimeter using linear regression, root mean square error and error percentage in estimating seasonal (ET0) and subsequently, the most appropriate models were recommended for the watershed.Results and Discussion Seasonal grass evapotranspiration measured from the lysimeter was 2729.8 mm and estimated by Adjusted penman and Blaney- Criddle, Penman-Monteith, Radiation and Evaporation pan 3405, 2695.2, 2868, 2789.2 and 2054.6 mm, respectively. The FAO adjusted Penman, Penman-Monteith and Radiation models overestimated ETo by as much as 24.7, 5.1 and 2.2% respectively, whereas, the FAO evaporation pan and Blaney- Criddle underestimated it by as much as 24.7 and 1.3%, respectively. Comparing weekly (ET0) data showed that adjusted penman model overestimated (ET0) but the FAO evaporation pan model underestimated it for most of the periods. FAO radiation model had tendency to overestimate at ETo10 mmday-1 (normally in Summer).Conclusion and Suggestions According to the results, the FAO Blaney-Criddle and Penman-Monteith models had respectively higher accordance and homogeneity with the real data measured from lysimeter and can predict (ET0) with higher accuracy than the other tested models. Therefore, these models are recommended, respectively as the most appropriate models to estimate (ET0) in Haji Abad Watershed and the areas having the same climate. Furthermore, the FAO Blaney-Criddle model needs fewer weather parameters and hence, may be used in the areas with limited climatic data.

Two separate experiments were conducted to investigate the performance of peppermint (Mentha piperita L.) in different water deficit and salinity management in 2017 and 2018, a randomized complete block design factorial experiment with three replications was designed in a lysimeter station in the Department of Water Engineering, Campus Agriculture, and Natural Resources of Razi University, Iran. The experiment included three levels of irrigation: 100%, 80% and 60%, and four salinity levels: (control), 2, 3 and 4 dS/m. The results indicated that the water deficit stress effect on aerial characteristics (leaf fresh weight, shoot fresh weight, leaf area, shoot height) and underground organs (root dry weight, root volume, root area, and root length), was significant. The irrigation water salinity effect in two years of the experiment was significant on leaf wet and dry weight, shoot wet and dry weight, leaf area and root dry weight, root volume, root area and root length. The mean comparison test revealed that the effect of deficit irrigation on shoot wet and dry weight was not significant between the 80% and 60% water requirement treatments. For 100% and 60% of irrigation requirements, the maximum and minimum leaf dry weight was observed at 2.47 and 1.54 g/plant in 2017. The mean comparison test result for salinity on underground organs showed that the highest root length in two years was observed in the control treatment and the lowest value of this parameter was observed in the 4 dS/m treatment. In general, water deficit and salinity had a negative effect on peppermint yield during two years of experiments. Therefore, it is not recommended to apply water stress and use water with a salinity of more than 2 ds/m to achieve the maximum yield.

Cultivation of medicinal plants with the irrigation of agricultural effluents might be of great importance to save fresh water resources, extend cultivation area and increase economic feasibility. We investigated the effects of saline fish farm effluent water, diluted and gypsum-supplemented effluent, and natural freshwater as a control irrigation in lysimeters. Beside plant growth parameters, macronutrient and sodium content and the amount and composition of essential oil of sage plants were measured. Significant differences among irrigation treatments were found in plant height, SPAD value and essential oil content. Seasonal variation was also observed on plant height, nutrient content of the leaves and the total essential oil content. The essential oil components characterised by the highest levels of availability were detected as α-thujone, camphor, ß-thujone, 1,8-cineol and ledol. Under effluent irrigation, the concentrations of - and ß-thujone increased slightly; only camphene, trans-sabinole and caryophyllene-oxide changed significantly. The other main components remained stable. Our analysis of the response of sage to the input of effluent provides a reasonable ground for recommending the utilisation of saline effluent water from intensive fish farming in sage production, thus preventing the wastage of valuable water resources.

Cultural and environmental factors can place creeping bentgrass (Agrostis stolonifera) under extreme stress during the summer months. This stress, coupled with the growth adaptation of creeping bentgrass, can result in shallow, poorly rooted stands of turf. To enhance root zone oxygen and rooting of creeping bentgrass, golf courses use methods such as core and solid-tine aerification, and sand topdressing. An additional method of delivering oxygen to the soil could be irrigation with nanobubble-oxygenated water. The properties of nanobubbles (NBs) allow for high gas dissolution rates in water. Irrigating with NB-oxygenated water sources may promote increased rooting of creeping bentgrass putting greens during high-temperature periods and lead to a more resilient playing surface. The objectives of this study include comparing the effects of irrigation with NB-oxygenated water sources with untreated water sources on creeping bentgrass putting green root zone and plant health characteristics using field and controlled environment experiments. Treatments included NB-oxygenated potable water and irrigation pond water, and untreated potable and irrigation pond water. In the field, NB-oxygenated water did not enhance plant health characteristics of creeping bentgrass. In 1 year, NB-oxygenated water increased the daily mean partial pressure of soil oxygen from 17.48 kPa to 18.21 kPa but soil oxygen was unaffected in the other 2 years of the trial. Subsurface irrigation with NB-oxygenated water did not affect measured plant health characteristics in the greenhouse. NB-oxygenation of irrigation water remains an excellent means of efficiently oxygenating large volumes of water. However, plant health benefits from NB-oxygenated irrigation water were not observed in this research.

Understanding trace element (TE) composition and behavior in soil solution is extremely important for assessing ecological and human health impacts. Using lysimeters to collect soil solution with minimum alteration to the in situ phase distribution and concentration of TEs will facilitate a more accurate assessment. However, different lysimeter materials and sampling conditions may lead to vastly different results, demonstrating the need for the optimal choice of lysimeter depending upon environmental conditions. There is no general agreement or overview discussing the best lysimeter type and sampling system to use under various conditions. This review provides a critical summary of various lysimeters that can be used to collect soil solutions for the analysis of TEs and thereby provides key guidance for developing the best lysimeter sampling system for conditions and research questions of interest. This includes a range of aspects related to lysimeters, such as different types and materials, the basic principles of design and operation, advantages and disadvantages, challenges and limitations, techniques for cleaning and pretreatment, correct installation procedures, the influence of soil physical and chemical properties on sampling, and existing research gaps within this field. [ABSTRACT FROM AUTHOR]

This study investigates the contamination potential of herbicides to groundwater with the help of numerical modeling (HYDRUS‐1D) and stable carbon isotopes for characterizing biodegradation. Four herbicides, metolachlor, terbuthylazine, prosulfuron, and nicosulfuron, were applied over a period of 4.5 years on two lysimeters located in Wielenbach, Germany, and monitored by lysimeter drainage. These lysimeters contained soil cores dominated by sandy gravel (Ly1) and clayey sandy silt (Ly2) and were both cropped with maize (Zea mays). In the preceding study, we characterized flow within the lysimeters by using stable water isotopes and unsaturated flow models. Building up on these findings, models were extended for describing reactive transport of the herbicides and investigating process contributions. At the end of the experiment, 0.9%–15.9% of the applied herbicides (up to 20.9% if including metabolites) were recovered by lysimeter drainage. Metabolite formation and accumulation was observed, and biodegradation was also indicated by small changes in carbon isotope signals (δ13C) between applied and leached herbicides. Model setups could describe the dynamics of herbicide concentrations in lysimeter drainage well. Concentration peaks in drainage were partly also linked with strong precipitation events, indicating preferential flow influence. The soil core with the coarser texture (Ly1) showed less herbicide leaching than the finer texture (Ly2), which can be explained by a larger mobile phase in Ly1. Overall, our approaches and findings contribute to the understanding of multi‐process herbicide transport in the vadose zone and leaching potentials to groundwater, where δ13C can provide valuable hints for microbial degradation. Core Ideas: Leached herbicide concentrations depend on the soil texture.Concentration peaks of herbicides in lysimeter drainage can be linked with rain events.Solute transport modeling allows us to identify dominant processes affecting herbicide leaching.Stable carbon isotopes measured in drainage can identify biodegradation processes in the unsaturated zone. [ABSTRACT FROM AUTHOR]

Understanding transport and fate processes in the subsurface is of fundamental importance to identify the leaching potentials of herbicides or other compounds to groundwater resources. HYDRUS‐1D was used to simulate water flow and solute transport in arable land lysimeters. Simulations were compared to observed drainage rates and stable water isotopes (δ18O) in the drainage. Four different model setups were investigated and statistically evaluated for their model performance to identify dominant processes for water flow characterization in the vadose zone under similar cultivation management and climatic conditions. The studied lysimeters contain soil cores dominated by sandy gravel (Ly1) and clayey sandy silt (Ly2), both cropped with maize located in Wielenbach, Germany. First, a single‐porosity setup was chosen. For Ly1, modeling results were satisfactory, but for Ly2, the damping observed in the isotope signature of the drainage could not be fully covered. By considering immobile water with a dual‐porosity setup for Ly2, model performance improved. This could be due to a higher fraction of fine pores in Ly2 available for water storage, leading to mixing processes of isotopically enriched summer precipitation and lighter winter water. Accounting for isotopic evaporation fractionation processes in both model setups did not lead to improved model performance. Consequentially, the difference in soil hydraulic properties between the two lysimeters seems to impact water flow processes. Knowledge of such differences is crucial to prevent contamination and mitigate potential risks to soil and groundwater. Core Ideas: For effective model description, multi‐process modeling must be explored.Mixing processes between immobile and mobile water are of greater importance for finer soils.Evaporation fractionation effects have no clear impact on simulated stable water isotopes in lysimeter drainage. [ABSTRACT FROM AUTHOR]

Accurate precipitation data are essential for assessing the water balance of ecosystems. Methods for point precipitation determination are influenced by wind, precipitation type and intensity and/or technical issues. High-precision weighable lysimeters provide precipitation measurements at ground level that are less affected by wind disturbances and are assumed to be relatively close to actual precipitation. The problem in previous studies was that the biases in precipitation data introduced by different precipitation measurement methods were not comprehensively compared with and quantified on the basis of those obtained by lysimeters in different regions in Germany. The aim was to quantify measurement errors in standard precipitation gauges as compared to the lysimeter reference and to analyze the effect of precipitation correction algorithms on the gauge data quality. Both correction methods rely on empirical constants to account for known external influences on the measurements, following a generic and a site-specific approach. Reference precipitation data were obtained from high-precision weighable lysimeters of the TERrestrial ENvironmental Observatories (TERENO)-SOILCan lysimeter network. Gauge types included tipping bucket gauges (TBs), weighable gauges (WGs), acoustic sensors (ASs) and optical laser disdrometers (LDs). From 2015-2018, data were collected at three locations in Germany, and 1 h aggregated values for precipitation above a threshold of 0.1 mm h -1 were compared. The results show that all investigated measurement methods underestimated the precipitation amounts relative to the lysimeter references for long-term precipitation totals with catch ratios (CRs) of between 33 %–92 %. Data from ASs had overall biases of -0.25 to -0.07 mm h -1 , while data from WGs and LDs showed the lowest measurement bias (-0.14 to -0.06 mm h -1 and -0.01 to -0.02 mm h -1). Two TBs showed systematic deviations with biases of -0.69 to -0.61 mm h -1 , while other TBs were in the previously reported range with biases of -0.2 mm h -1. The site-specific and generic correction schemes reduced the hourly measurement bias by 0.13 and 0.08 mm h -1 for the TBs and by 0.09 and 0.07 mm h -1 for the WGs and increased long-term CRs by 14 % and 9 % and by 10 % and 11 %, respectively. It could be shown that the lysimeter reference operated with minor uncertainties in long-term measurements under different site and weather conditions. The results indicate that considerable precipitation measurement errors can occur even at well-maintained and professionally operated stations equipped with standard precipitation gauges. This generally leads to an underestimation of the actual precipitation amounts. The results suggest that the application of relatively simple correction schemes, manual or automated data quality checks, instrument calibrations, and/or an adequate choice of observation period can help improve the data quality of gauge-based measurements for water balance calculations, ecosystem modeling, water management, assessment of agricultural irrigation needs, or radar-based precipitation analyses. [ABSTRACT FROM AUTHOR]

Abstract This study aimed to accurately estimate daily wheat evapotranspiration using two remote sensing algorithms, Surface Energy Balance System (SEBS) and Surface Energy Balance Algorithm for Land (SEBAL), in central Khuzestan province during 2019–2020. The results of two algorithms were compared with lysimeter (as a direct method), FAO-Penman–Monteith (FAO-PM), two temperature-based methods (Hargreaves-Samani and Blaney-Criddle), two radiation-based methods (Priestley–Taylor and Doorenbos–Pruitt), and two mass transfer-based methods (Mahringer and World Meteorology Organization) (as indirect methods). Coefficient of Determination (R 2), Root-Mean-Square Error (RMSE), Percentage of Bias (PBIAS), Mean Bias Error, Mean Absolute Percentage Error, and Nash–Sutcliffe indicators used for comparing the results. According to the results, both SEBAL and SEBS algorithms showed the highest compatibility with lysimeter data (R 2 = 0.92 and 0.96, RMSE = 2.15 and 1.53 mm/day, respectively). Comparing both algorithms with the FAO-PM method, resulted in RMSE and R 2 of 2.42 mm/day and 0.87 for SEBS and 3.14 mm/day and 0.79 for SEBAL. The Hargreaves-Samani method (R 2 = 0.72, RMSE = 16.4 mm/day) and (R 2 = 0.8, RMSE = 10.4 mm/day) among temperature-based methods, Doorenbos–Pruitt (R 2 = 0.71, RMSE = 3.33 mm/day) and (R 2 = 0.79, RMSE = 2.63 mm/day) among radiation-based methods, and the Mahringer method (R 2 = 0.6, RMSE = 6.8 mm/day mm/day) and (R 2 = 0.68, RMSE = 5.51 mm/day) among mass transfer-based methods yielded better estimations than SEBAL and SEBS algorithms, respectively. Owing to the high accuracy of SEBAL and SEBS algorithms, in estimating the amount of evapotranspiration in the study area and close to the actual values in the field, using energy balance algorithms is recommended in Khuzestan province.

The availability of irrigation water during the growing season reflects on the potential yield at the end of the peanuts’ growing season. Monitoring water availability is essential to optimize production. This study aimed to identify the effect of irrigation water on peanuts (Arachis hypogaea (L.) Merr.) under various irrigation conditions between actual and simulated AquaCrop. The research was conducted in the experimental field utilizing four irrigation treatments which were 60%, 80%, 100% of field capacity (FC), and standard irrigation. The correlation results between the actual and simulated ones showed that the R2 value was 0.974–0.990 for the canopy cover parameter, 0.026–0.534 for ETc, and 0.542-0.554 for production. Comparison between actual and simulated AquaCrop showed Root Mean Square Error (RMSE) values of 5.08–­­9.74 for canopy cover parameters, 1.11–3.12 for ETc, and 0.82–1.09 for production. Welch test statistical analysis indicated values of 2.31–5.52 for plant biomass and 0.04–3.98 for dry pod yields. The AquaCrop simulation accurately predicted canopy cover at 80% irrigation treatment compared to 60%, 100%, and standard irrigation treatments. Parameter of ETc in AquaCrop simulations showed inaccurate predictions for biomass production and pod dry weight when compared with actual results on all irrigation treatments.

Ginger (Zingiber officinale var. rubrum) is a rhizome plant that can benefit health, fitness and be used as a spice. The content contained in ginger can prevent and treat various diseases and act as an antioxidant and anti-inflammatory agent. The cultivation of ginger plants requires adequate nutrients and water for development and growth. Crop water requirements are influenced by crop coefficients which vary according to the plant growth stage. The crop coefficient values are needed for irrigation management and increasing irrigation efficiency. The main objective of the current study was to investigate the crop coefficient value of ginger by lysimeter. Lysimeter is a water balance device with the principle of mass conservation, where the input is rainfall and irrigation while the output is percolation and evapotranspiration. The rainfall during the investigated period was 0–62.82 mm·day−1, humidity 70.7–89.4%, and air temperature 23.7–32.9 °C. The crop coefficient of ginger increased during the vegetative growth period, i.e., 0.997 in the seedling stage, 1.072 in the tiller stage, and 1.138 in the advanced vegetative stage. The crop coefficient of red ginger was determined using a lysimeter quite accurately, with a coefficient of determination value (R2) 0.950 and a significant value of F less than 0.05.

We developed a set of two precision, small-scale, water balance lysimeters to provide accurate measurements of bare soil evaporation. Each lysimeter comprises a soil tank, a balance assembly with load cell, a wicking drainage system, and a stilling well to measure drained water. Fiberglass wicks installed at the bottom of the soil tanks provide −60 cm of tension to the base of the soil column, and soil water drainage is quantified to close the water balance within the lysimeter. The calibrated lysimeters return mass changes with uncertainties ranging from 3 to 8 g, corresponding to uncertainties of 0.02–0.05 mm of water. Installed at a semi-arid site in northern Nevada, the two lysimeters are filled with uniform construction sand and silt loam. Over a six-month pilot observation period, bare soil evaporation rates of 0.19 and 0.40 mm/day were measured for the construction sand and silt loam, respectively, which is consistent with meteorological data and models of potential evapotranspiration at the site. The design of the lysimeter can be adapted to specific research goals or site restrictions, and these instruments can contribute significantly to our ability to close the soil water balance.

Precise water management is imperative for sustainable crop production under irrigation in semi-arid regions with increasingly variable rainfall. Water use efficiencies achieved by farmers often differ widely, even within regions with homogenous agro-ecological conditions. To better understand the drivers of this variability and derive management recommendations, detailed measurements of water and associated nutrient dynamics were conducted on 20 potato farms in two regions of South Africa. Crop characteristics and typical growing conditions in South Africa make potato cultivation sensitive to water and nutrient losses. Water and nutrient inputs and losses through drainage and plant uptake were measured in potato and the follow-up crop, along with yield and weather variables. Seasonal mean irrigation and evapotranspiration were lower in winter crops (240 mm irrigation, 236 mm evapotranspiration) than in summer crops (598 mm irrigation, 608 mm evapotranspiration). Seasonal field water balances were often close to zero, indicating that estimations of evapotranspiration and drainage were representative for the greater field. Lysimeter observations however appeared more representative in sandy unstructured soils than in heavier structured soils. Rainfall during cropping reduced demand for irrigation and increased water use efficiency based on irrigation water, but caused substantial drainage. Leaching of N and K was considerable (on average 30 kg N, 55 kg K ha−1, much higher in some fields), while P leaching was negligible, with the exception of one field (51 kg P ha−1). Variation in water and nutrients use efficiencies was the result of management decisions and environmental factors, such as rainfall and soil type. Without substantial rainfall, application of irrigation scheduling tools can keep drainage and nutrient losses to a minimum, as was observed on almost half the fields, even on sandy soils with a low water holding capacity. Potato yields greatly varied among farmers (9.1–24.7 t dry matter tuber ha−1). Efficient farmers included those who used water sparsely and had minimal drainage, but also farmers who used inputs judiciously and obtained excellent productivity. The role of follow-up crops as users of surplus nutrients and water left behind by the potato crop was not always evident.

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Salinity is a major abiotic constraint faced by farmers in many rice-growing regions of the world and improving grain yield in rice is the most important breeding objective. Thirty-five crosses were generated in a line x tester mating design by crossing seven lines with five testers and were evaluated in a randomized complete block design at the greenhouse lysimeter of Rice Research Department, Sakha, Kafr El-Sheikh, Egypt, during the two rice-growing seasons of May, 2021 and 2022. Analysis of variance revealed a highly significant difference among testers and lines for all the studied traits. Variances of specific combining ability were higher in magnitude than the corresponding general combining ability. The lines Sakha 107, Sakha 104, and Giza 182 including testers SAL 010, and CSR 28 were the best general combiners for grain yield plant-1 under saline conditions. The variety Giza 179 followed by Sakha 107 was the best general combiner for 100-grain weight under both normal and saline conditions. Two crosses Giza 179/MTU 1010 and Sakha 107/SAL 010 exhibited highly significant positive estimates of specific combining effects for grain yield plant-1, respectively. Estimates of narrow sense heritability for all the traits under study were low which indicated a preponderance of non-additive gene action governing these traits. By selecting the appropriate genotypes and phenotypes, the outcomes will be beneficial in breeding salt-tolerant cultivars at both the seedling and reproductive stages. [ABSTRACT FROM AUTHOR]

A quantitative understanding of actual evapotranspiration (ETa) and soil–water dynamics in a hillslope agroecosystem is vital for sustainable water resource management and soil conservation; however, the complexity of processes and conditions involving lateral subsurface flow (LSF) can be a limiting factor in the full comprehension of hillslope soil–water dynamics. The research was carried out at SUPREHILL CZO located on a hillslope agroecosystem (vineyard) over a period of two years (2021–2022) by combining soil characterization and field hydrological measurements, including weighing lysimeters, sensor measurements, and LSF collection system measurements. Lysimeters were placed on the hilltop and the footslope, both having a dynamic controlled bottom boundary, which corresponded to field pressure head measurements, to mimic field soil–water dynamics. Water balance components between the two positions on the slope were compared with the goal of identifying differences that might reveal hydrologically driven differences due to LSF paths across the hillslope. The usually considered limitations of these lysimeters, or the borders preventing LSF through the domain, acted as an aid within this installation setup, as the lack of LSF was compensated for through the pumping system at the footslope. The findings from lysimeters were compared with LSF collection system measurements. Weighing lysimeter data indicated that LSF controlled ETa rates. The results suggest that the onset of LSF contributes to the spatial crop productivity distribution in hillslopes. The present approach may be useful for investigating the impact of LSF on water balance components for similar hillslope sites and crops or other soil surface covers. [ABSTRACT FROM AUTHOR]

Soil water drainage is the main source of groundwater recharge and river flow. It is therefore a key process for water resource management. In this study, we evaluate the soil hydrology and the soil water drainage, simulated by the interactions between soil–biosphere–atmosphere (ISBA) land surface model currently used for hydrological applications from the watershed scale to the global scale, where parameters are generally not calibrated. This evaluation is done using seven lysimeters from two long-term model approach sites measuring hourly water dynamics between 2009 and 2019 in northeastern France. These 2 m depth lysimeters are filled with different soil types and are either maintained as bare soil or covered with vegetation. Four closed-form equations describing soil water retention and hydraulic conductivity functions are tested, namely the commonly used equations from and , a combination of the soil water retention function with the unsaturated hydraulic conductivity function, and, for the very first time in a land surface model (LSM), a modified version of the equations, with a new hydraulic conductivity curve proposed by. The results indicate good performance by ISBA with the different closure equations in terms of soil volumetric water content and water mass. The drained flow at the bottom of the lysimeter is well simulated, using , while some weaknesses appear with due to the abrupt shape near the saturation of its hydraulic conductivity function. The mixed form or the new hydraulic conductivity function from allows the solving of this problem and even improves the simulation of the drainage dynamic, especially for intense drainage events. The study also highlights the importance of the vertical heterogeneity of the soil hydrodynamic parameters to correctly simulate the drainage dynamic, in addition to the primary influence of the parameters characterizing the shape of the soil water retention function. [ABSTRACT FROM AUTHOR]

Soil compaction caused by traffic is commonly considered as one of the major's problems in agriculture. Moisture content has a significant effect on amplifying soil compaction. This study aims to approach evaporation trend of a vertisol (40.47% clay, 39.30% loam and 20.23% sand) having an organic matter content of 1.5% in order to manage timing of its plasticity as a determinant factor inducing compaction created by the traffic of machines. A portable lysimetric measurement system was developed to evaluate soil evaporation trend. An empirical soil evaporation equation was developed using three measurement campaigns according to different temperature and irradiance behaviors. Soil moisture content was evaluated with two sensors using conductivity and matric potential methods. Data were acquired using an Arduino UNO platform. Climatic data obtained from a meteorological station was used for computing evapotranspiration using Penman-Monteith model as reference for evaluation of the evaporation equation output. According to different climatic behaviors, the rate of vertisol evaporation showed a decrease in moisture content in three campaigns that have two repetitions (2 repetitions/3 campaigns). In the first one (C1), the soil moisture content arranged from 46% to 8% and from 43% to 8%. In the C2 the soil moisture varied from 47% to 7% and from 49% to 6%. Similarly, it changed from 47% to 6% and from 46% to 9% in the third campaign (C3). The occurrence of plasticity interval was between the 4th and the 11th day in the first campaign, the 6th and the 15th day in the second campaign and between the 10th and the 22th in the third campaign. Finally, compared with simulated results developed by an equation in Matlab Simulink, an important correlation has been shown. As a conclusion, we can predict plasticity limits by using soil water content measurements and climatic data (Temperature and Irradiance). [ABSTRACT FROM AUTHOR]

Two separate experiments were conducted to investigate the performance of peppermint (Mentha piperita L.) in different water deficit and salinity management in 2017 and 2018, a randomized complete block design factorial experiment with three replications was designed in a lysimeter station in the Department of Water Engineering, Campus Agriculture, and Natural Resources of Razi University, Iran. The experiment included three levels of irrigation: 100%, 80% and 60%, and four salinity levels: (control), 2, 3 and 4 dS/m. The results indicated that the water deficit stress effect on aerial characteristics (leaf fresh weight, shoot fresh weight, leaf area, shoot height) and underground organs (root dry weight, root volume, root area, and root length), was significant. The irrigation water salinity effect in two years of the experiment was significant on leaf wet and dry weight, shoot wet and dry weight, leaf area and root dry weight, root volume, root area and root length. The mean comparison test revealed that the effect of deficit irrigation on shoot wet and dry weight was not significant between the 80% and 60% water requirement treatments. For 100% and 60% of irrigation requirements, the maximum and minimum leaf dry weight was observed at 2.47 and 1.54 g/plant in 2017. The mean comparison test result for salinity on underground organs showed that the highest root length in two years was observed in the control treatment and the lowest value of this parameter was observed in the 4 dS/m treatment. In general, water deficit and salinity had a negative effect on peppermint yield during two years of experiments. Therefore, it is not recommended to apply water stress and use water with a salinity of more than 2 ds/m to achieve the maximum yield. [ABSTRACT FROM AUTHOR]

This study aimed to accurately estimate daily wheat evapotranspiration using two remote sensing algorithms, Surface Energy Balance System (SEBS) and Surface Energy Balance Algorithm for Land (SEBAL), in central Khuzestan province during 2019–2020. The results of two algorithms were compared with lysimeter (as a direct method), FAO-Penman–Monteith (FAO-PM), two temperature-based methods (Hargreaves-Samani and Blaney-Criddle), two radiation-based methods (Priestley–Taylor and Doorenbos–Pruitt), and two mass transfer-based methods (Mahringer and World Meteorology Organization) (as indirect methods). Coefficient of Determination (R2), Root-Mean-Square Error (RMSE), Percentage of Bias (PBIAS), Mean Bias Error, Mean Absolute Percentage Error, and Nash–Sutcliffe indicators used for comparing the results. According to the results, both SEBAL and SEBS algorithms showed the highest compatibility with lysimeter data (R2 = 0.92 and 0.96, RMSE = 2.15 and 1.53 mm/day, respectively). Comparing both algorithms with the FAO-PM method, resulted in RMSE and R2 of 2.42 mm/day and 0.87 for SEBS and 3.14 mm/day and 0.79 for SEBAL. The Hargreaves-Samani method (R2 = 0.72, RMSE = 16.4 mm/day) and (R2 = 0.8, RMSE = 10.4 mm/day) among temperature-based methods, Doorenbos–Pruitt (R2 = 0.71, RMSE = 3.33 mm/day) and (R2 = 0.79, RMSE = 2.63 mm/day) among radiation-based methods, and the Mahringer method (R2 = 0.6, RMSE = 6.8 mm/day mm/day) and (R2 = 0.68, RMSE = 5.51 mm/day) among mass transfer-based methods yielded better estimations than SEBAL and SEBS algorithms, respectively. Owing to the high accuracy of SEBAL and SEBS algorithms, in estimating the amount of evapotranspiration in the study area and close to the actual values in the field, using energy balance algorithms is recommended in Khuzestan province. [ABSTRACT FROM AUTHOR]

【Objective】 Evapotranspiration consists of plant transpiration (Tr) and soil surface evaporation (Es); It is a critical component in the hydrological cycle, often estimated using meteorological and plant data. We present a modified method in this paper to improve its calculation. 【Method】 The method was based on the Penman-Monteith (P-M) equation using the dual crop coefficients as recommended by FAO-56. The methods for calculating the base crop coefficient (Kcb) and soil evaporation coefficient (Ke) in the equation are modified using the leaf area index (LAI), meteorological factors and soil water content. The modified model is then used to estimate real evapotranspiration (ETc) from the reference crop evapotranspiration (ET0) calculated from the P-M model. We test the model against data measured in 2018—2019 from large scale lysimeters grown with summer maize at the Wudaogou Hydrological Experimental Station in Anhui province. 【Result】 The modified dual crop coefficient model improved the accuracy of the estimated evapotranspiration, with the estimated average daily evapotranspiration being 4.89 mm/d (the measured was 4.66 mm/d) in 2018, and 5.72 mm/day (the measured was 5.67 mm/d) in 2019. The R2, RMSE, Ens and AAE of the modified model were 0.89, 0.98 mm/d, 0.86 and 0.73 mm/d, respectively, in 2018; and 0.89, 0.76 mm/d, 0.89 and 0.58 mm/d, respectively, in 2019. 【Conclusion】 The modified dual crop coefficient method is robust and improves the accuracy of the estimated evapotranspiration from summer maize fields, compared with the traditional method.