Effect of vanadium in irrigation water on sunflower and soybean

A representative agricultural area of 150 ha located in a protected ecosystem (Axios River Delta, Thermaikos Gulf-N. Aegean, Greece) was selected in order to investigate water quality parameters [pH, electrical conductivity (EC(w)), NO(3)-N, NH(4)-N, total phosphorus (TP)] in irrigation and drainage water. In the study area, the cultivated crops are mainly rice, maize, cotton, and fodder. Surface irrigation methods are applied using open channels network, and irrigation water is supplied by Axios River, which is facing pollution problems. The return flow from surface runoff and the surplus of irrigation water are collected to drainage network and disposed to Thermaikos Gulf. A 2-year study (2006-2007) was conducted in order to evaluate the effects of land use and irrigation water management on the drainage water quality. The average pH and NO(3)-N concentration was higher in the irrigation water (8.0 and 1.3 mg/L, respectively) than that in the drainage water (7.6 and 1.0 mg/L, respectively). The average EC(W), NH(4)-N, and TP concentration was higher in the drainage water (1,754 muS/cm, 90.3 microg/L, and 0.2 mg/L, respectively) than that in the irrigation water (477.1 muS/cm, 46.7 microg/L, and 0.1 mg/L, respectively). Average irrigation efficiency was estimated at 47% and 51% in 2006 and 2007 growing seasons (April-October), respectively. The loads of NO(3)-N in both seasons were higher in the irrigation water (35.1 kg/ha in 2006 and 24.9 kg/ha in 2007) than those in the drainage water (8.1 kg/ha in 2006 and 7.6 kg/ha in 2007). The load of TP was higher in the irrigation water in season 2006 (2.8 kg/ha) than that in the drainage water (1.1 kg/ha). Total phosphorus load in 2007 was equal in irrigation and drainage water (1.2 kg/ha). Wetland conditions, due to rice irrigation regime, drainage network characteristics, and the crop distribution in the study area, affect the drainage water ending in the protected ecosystem of Thermaikos Gulf.

Rising agricultural water scarcity in China is driven by expansion of irrigated cropland in water scarce regions

Characterization of water use and water balance for the croplands of Kansas using satellite, climate, and irrigation data

We conducted a greenhouse study on large, semi-disturbed soil cores excavated from the vicinity of Verdigris Lake in southern Alberta to assess the suitability of different saline-sodic waters for irrigation. Soil salinization and sodication, surface soil physical properties, and yield of five soft white spring wheat crops (Triticum aestivum L. var. AC Reed) were examined under alternate applications of simulated rain with saline-sodic irrigation waters ranging from "safe" to "potentially hazardous" for irrigation. Increased salinity and sodicity of irrigation waters alternated with simulated rain resulted in increased salinity and sodicity in the upper 0.60 to 0.90 m of the soil. Salt accumulation in the root zone decreased as the leaching fraction increased. Aggregate stability and infiltration properties of the soil were generally adversely affected by the more saline and sodic irrigation waters. Infiltration properties were significantly greater with irrigation water (IW) than with distilled water (DW). The soil infiltration rate at 2 h, with DW as the infiltrating water, was the most sensitive soil physical property for assessment of irrigation water suitability. The infiltration test after five crop cycles gave a better indication of the effects of excess sodicity of irrigation water on soil structural stability than the aggregate stability test. The cumulative effects of long-term supplemental irrigation with saline-sodic waters on soil chemical and physical properties need to be considered when assessing irrigation water suitability. Irrigation waters with electrical conductivity (EC) less than or equal to 1 dS m-1 and a sodium adsorption ratio (SAR) less than or equal to 5 did not result in deterioration of soil physical properties and were considered "safe" for supplemental irrigation of the Masinasin soil. Alternate applications of irrigation and distilled water should be used to evaluate soil infiltration rates and the structural stability of soils to which saline-sodic waters are to be applied. Key words: Saline-sodic irrigation water, soil salinity, soil sodicity, aggregate stability, infiltration, water quali

Effect of irrigation amount and water salinity on water consumption and water productivity of spring wheat in Northwest China

The aim of this study was to assess the color changes in artificially induced incipient caries after photodynamic therapy (PDT) using different concentrations of methylene blue and toluidine blue, along with irrigation using water and hypochlorite. Forty-two sound human premolar teeth were used to create two artificial incipient carious lesions. One lesion was placed on the buccal surface and the other on the lingual surface. The color of these artificial incipient carious surfaces was determined using the CIE L ∗ a ∗ b ∗ color system. The teeth were then randomly assigned to 12 groups (n = 7) based on the PDT method. These methods included methylene blue with concentrations of 50, 100, and 150 µg/mL, followed by water irrigation, methylene blue with concentrations of 50, 100, and 150 µg/mL, followed by hypochlorite solution irrigation, toluidine blue with concentrations of 50, 100, and 150 µg/mL, followed by water irrigation, and toluidine blue with concentrations of 50, 100, and 150 µg/mL, followed by hypochlorite solution irrigation. The teeth underwent a colorimetry procedure again, and the resulting color changes were calculated. A three-way ANOVA was performed to analyze the effects of laser wavelength, concentration of the light-absorbing material, and irrigation solution on ΔE. The results showed that the color changes caused by toluidine blue photosensitizer at a concentration of 100 µg/mL, with both water and hypochlorite irrigation, were not noticeable to the naked eye (ΔEwater = 3.04, ΔEhypochlorite = 2.00). However, in the other study groups, the color changes were perceptible (ΔE > 3.3). There were no significant differences in ΔE between different concentrations of methylene blue and toluidine blue when using either water or hypochlorite irrigation (P > 0.05). A significant difference was observed between methylene blue and toluidine blue at a concentration of 100 µg/mL with water irrigation (P=0.006). Additionally, a significant difference was found between methylene blue and toluidine blue at a concentration of 100 µg/mL with hypochlorite irrigation (P=0.049). However, no significant differences were observed between methylene blue and toluidine blue at other concentrations with either water or hypochlorite irrigation (P > 0.05). In conclusion, tooth color in teeth with incipient caries did not change significantly after PDT using toluidine blue (the photosensitizer) at a concentration of 100 µg/mL with either water or 1% hypochlorite solution irrigation for 5 s.

Estimating irrigation water use accurately is critical for sustainable irrigation and studying terrestrial water cycle in irrigated croplands. However, irrigation is not monitored in most places, and current estimations of irrigation water use has coarse spatial and/or temporal resolutions. This study aims to estimate irrigation water use at the daily and field scale through the proposed model‐data fusion framework, which is achieved by particle filtering with two configurations (concurrent, CON, and sequential, SEQ) by assimilating satellite‐based evapotranspiration (ET) observations into an advanced agroecosystem model, ecosys. Two types of experiments using synthetic and real ET observations were conducted to study the efficacy of the proposed framework for estimating irrigation water use at the irrigated fields in eastern and western Nebraska, United States. The experiments using synthetic ET observations indicated that, for two major sources of uncertainties of ET difference between observations and model simulations, which are bias and noise, noise had larger impacts on degrading the estimation performance of irrigation water use than bias. For the experiments using real ET observations, monthly and annual estimations of irrigation water use matched well with farmer irrigation records, with Pearson correlation coefficient (r) around 0.80 and 0.50, respectively. Although detecting daily irrigation records was very challenging, our method still gave a good performance with RMSE, BIAS, and r around 2.90, 0.03, and 0.4 mm/d, respectively. Our proposed model‐data fusion framework for estimating irrigation water use at high spatio‐temporal resolution could contribute to regional water management, sustainable irrigation, and better tracking terrestrial water cycle.

Applications of modern micro-irrigation methods are inevitable for optimum water use due to the limitations imposed by irrigation water resource scarcity. Regardless of water shortages and associated challenges in dry areas, the irrigation of date palm trees consumes an excessive quantity of water annually using conventional irrigation methods. Therefore, the present study was designed to evaluate the effects of modern surface and subsurface micro-irrigation systems, i.e., subsurface drip irrigation (SSDI), controlled surface irrigation (CSI), and surface drip-irrigation methods (SDI), with different irrigation water regimes, i.e., 50%, 75%, and 100% irrigation water requirements (IWRs), on the yield and fruit quality of date palms (cv. Khalas) and water conservation in the dryland region of Al-Ahsa, Saudi Arabia. The effects of three irrigation methods and IWRs were studied on macronutrients and soil chemical properties at three depths (0–30, 30–60, and 60–90 cm), as well as on water productivity, yield, and the fruit quality of date palms. The study was carried out over two years and was designed using a two-factorial randomized complete block design (RCBD) with nine replications. The results indicated that electrical conductivity (EC) increased as the depth of the soil increased. The soil chemical properties did not change much in all experimental treatments, while soil pH values decreased with the soil depth from 0–30 to 60–90 cm. Although the maximum fruit yield (96.62 kg palm−1) was recorded when 100% irrigation water was applied in the SSDI system, other treatment combinations, such as SDI at 100% IWR (84.86 kg palm−1), SSDI at 75% IWR (84.84 kg palm−1), and CSI at 100% IWR (83.86 kg palm−1) behaved alike and showed promising results. Similarly, the highest irrigation water productivity (2.11 kg m−3) was observed in the SSDI system at 50% IWR, followed by the SSDI at 75% IWR (1.64 kg m−3) and 100% IWR (1.40 kg m−3). Fruit quality attributes were also promoted with the SSDI system at 75% IWR. Hence, the SSDI method at 75% IWR appeared to be an optimal choice for date palm irrigation in arid areas due to its positive impact on water conservation and fruit characteristics without affecting soil chemical properties.

Irrigation of agricultural oases is the main water consumer in semi‐arid and arid regions of Northwestern China. The accurate estimation of evapotranspiration (ET) on the oases is extremely important for evaluating water use efficiency so as to reasonably allocate water resources, particularly in semi‐arid and arid areas. In this study, we integrated the soil moisture information into surface energy balance system (SEBS) for improving irrigated crop water consumption estimation. The new approach fed with the moderate resolution imaging spectro‐radiometer images mapped spatiotemporal ET on the oasis in the middle reach of the Heihe river. The daily ET outputs of the new approach were compared with those of the original SEBS using the eddy correlation observations, and the results demonstrate that the modified SEBS remedied the shortcoming of general overestimating ET without regard to soil water stress. Meanwhile, the crop planting structure and leaf area index spatiotemporal distribution in the studied region were derived from the high‐resolution Chinese satellite HJ‐1/CCD images for helping analyse the pattern of the monthly ET (ETmonthly). The results show that the spatiotemporal variation of ETmonthly is closely related to artificial irrigation and crop growth. Further evaluation of current irrigation water use efficiency was conducted on both irrigation district scale and the whole middle reach of the Heihe river. The results reveal that the average fraction of consumed water on irrigation district scale is 57% in 2012. The current irrigation water system is irrational because only 52% of the total irrigated amount was used to fulfil plant ET requirement and the rest of the irrigation water recharged into groundwater in the oasis in 2012. However, in view of the whole middle reach of the Heihe river, the irrigation water use efficiency could reach to 66% in 2012. But pumping groundwater for reused irrigation wastes mostly energy instead of water. An improved irrigation water allocation system according to actual ET requirement is needed to increase irrigation efficiency per cubic meter water resource in an effort to save both water and energy. Copyright © 2014 John Wiley & Sons, Ltd.

Present study on the assessment of underground water quality for irrigation purpose in different villages of Shahabad block of Kurukshetra district of Haryana was carried out during 2023-2024 to get a comprehensive picture of the groundwater quality for irrigation purposes of the area. Total 64 underground water samples were collected and analyzed for various chemical parameters i.e. EC, pH, dominated cations and anions. Irrigation water parameters such as RSC, SAR, were also computed in the water samples. The EC, pH, RSC and SAR of the groundwater ranged from 0.46-1.83 dSm-1, 7.31 to 8.80, 0.00 - 4.85 meq L-1 and 2.37-12.81 (mmol L-1)1/2, respectively. The trend among the mean ionic concentration of anions was found to be in the order of Cl- > HCO3 > SO42- > CO32- and likewise mean ionic concentration of the cations was in the order Na+> Mg2+ > Ca2+ > K+ showing the dominance of chloride ions among anions and sodium ion among cations in the irrigation water. This study conducted in Shahbad block of Kurukshetra district in Haryana had the outcome that 95.7 and 6.25 per cent samples were found good and marginally alkali respectively as per AICRP, 1989 criteria. Spatial variability maps of EC, SAR and RSC of ground water used for irrigation in the block were also prepared. Marginally alkali irrigation (6.25 %) water in Shahabad block may be used with recommended amount of gypsum based on RSC of the water along with the irrigation water. Thus, the current study suggests to safely use 6.25% of marginally alkali irrigation water with certain amendments and strategic measure so we may prevent the ill effects of alkali water on soil for long run and we may achieve the goal of sustainable agriculture production.

Assessment of socioeconomic aspects in irrigation water use inefficiency in Sudan

Evaluation of the influence of irrigation methods and water quality on sugar beet yield and water use efficiency

Current irrigation scheduling is based on well-established crop coefficient and reference evapotranspiration procedures to estimate daily crop evapotranspiration (ETc). Effective irrigation scheduling and efficient irrigation water use can occur when ETc is calculated with crop coefficients representative of actual crop water use conditions. The objective of this research was to evaluate irrigation scheduling using two approaches to estimate the basal crop coefficient (Kcb) during wheat experiments conducted in 2003-2004 and 2004-2005 at Maricopa, Arizona. Each Kcb approach (main treatment) included six subtreatment combinations (three plant densities and two N managements) imposed to create spatial and temporal variations in water use among experimental plots. The first approach (NDVI treatment) estimated Kcb separately for each plot based on normalized difference vegetation index (NDVI) data obtained by frequent canopy reflectance measurements. The second approach (FAO treatment) estimated Kcb uniformly for all plots based on a Kcb curve developed for standard wheat conditions. The Kcb estimates were incorporated within the FAO-56 dual crop coefficient procedures to calculate daily ETc and root zone soil water depletion (Dr). Plot irrigations were provided when the predicted Dr reached 45% of the available soil water. During both wheat experiments, considerable variations in measured soil water depletion were observed for subtreatments due to differences in crop water use rates. For the FAO treatment, mean absolute percent difference (MAPD) for predicted Dr was 27% and 40% for 2003-2004 and 2004-2005, respectively. Prediction of Dr was improved significantly for NDVI for both experiments where treatment MAPD was 17% (2003-2004) and 18% (2004-2005). Although mean irrigation application efficiency for NDVI (89%) and FAO (88%) was similar for 2003-2004, it was significantly higher for NDVI (86%) than FAO (77%) for 2004-2005. Differences for irrigation scheduling resulted in significantly lower seasonal irrigation water use for the NDVI than FAO treatment, 8% (2003-2004) and 13% (2004-2005), but did not result in appreciable treatment differences for seasonal ETc, final grain yield, and crop water use efficiency (yield per unit ETc). Consequently, a primary outcome for both experiments was significantly higher irrigation water use efficiency (yield per unit irrigation water) for NDVI than FAO. Incorporating Kcb estimates based on NDVI within existing crop coefficient algorithms provides an opportunity to improve wheat irrigation scheduling strategies for conserving irrigation water while maintaining grain yield potentials.

<p>Understanding the dynamics and sources of root water uptake in agricultural systems is becoming increasingly important for implementing efficient and sustainable water resources management and, at the same time, for optimizing crop yield and quality under changing climatic conditions. In this work, we adopted the stable isotope approach to investigate the water sources accessed by apple trees in two orchards growing in the upper Etsch/Adige valley (South Tyrol, Eastern Italian Alps). We tested the general hypothesis that soil water, composed of a mixture of rain and irrigation water, was the main source for tree transpiration but that river water and groundwater mixed with soil water and contributed to root uptake for trees growing close to the river and with higher water table. Our results revealed that apple trees during the 2015 and 2016 growing seasons relied mostly on soil water present in the upper 20-40 cm of soils, with an apparently negligible contribution of groundwater and river water, irrespective of the field position across the valley bottom. The isotopic composition of xylem water did not reflect the one of irrigation water (and neither that of groundwater) but rather of rainfall and throughfall, as well as that of soil water. We related this “hidden” tracer signature of irrigation water to the effect of soil evaporation that strongly modified its original isotopic composition: irrigation and rain water infiltrated into the soil and mixed with isotopically fractionated soil water, and trees took up a mixture of water with different isotopic composition compared to the one of the original irrigation source. This work contributes to improve the understanding of water uptake strategies in Alpine apple orchards and paves the way for further analysis on the proportion of irrigation and rain water used by apple trees in mountain agroecosystems.</p>

Comparing water input and water productivity of transplanted and direct-seeded rice production systems