Alternative Irrigation Research Articles

Evaluation of Antimicrobial Efficacy of 3.8% Silver Diamine Fluoride as a Root Canal Irrigant against Enterococcus Faecalis in Primary Teeth: A Randomised Clinical Trial

Introduction: During a pulpectomy, the infected or inflamed pulp tissues are removed, and the root canal is thoroughly cleaned with mechanical instrumentation and copious irrigation. Various endodontic irrigants are available, such as Sodium Hypochlorite (NaOCl), Chlorhexidine (CHX) gluconate, Ethylene Diamine Tetra Acetic Acid (EDTA), Mixture of doxycycline, citric acid, and a detergent (MTAD), etc. Among these, CHX gluconate is widely used as an endodontic irrigant and medicament due to its antibacterial effect and substantivity. Enterococcus faecalis is the most common bacterial species found in necrotic teeth, with high viability and antibiotic resistance. A 3.8% Silver Diamine Fluoride (SDF) has antimicrobial properties and has been shown to eliminate E. faecalis from the root canals of permanent teeth. However, there are no studies in the literature that have evaluated its efficacy as a root canal irrigant in primary teeth. Aim: To evaluate the antimicrobial efficacy of 3.8% SDF against E. faecalis in primary teeth. Materials and Methods: This was a in-vivo double-blinded randomised clinical trial conducted at Department of Paediatric and Preventive Dentistry, GSL Dental College and Hospital, Rajahmundry, Andhra Pradesh, India in children aged 3-8 years old. The study included 60 primary teeth that required pulpectomy. The teeth were divided into two groups and irrigated: 30 teeth with 3.8% SDF (Group I) and 30 teeth with 2% CHX (Group II). In all cases, two microbiological samples were taken using sterile absorbent paper points: the first after access opening and the second after the final irrigation. All samples were assessed using the agar plate method. The results were analysed statistically using a Student's paired t-test. Results: After analysing the pre- and postirrigation samples, there was a statistically significant reduction in Colony Forming Units (CFU)mL (p<0.05) in both groups. When comparing the two groups, no statistical difference was observed in the percentage reduction of bacterial colonies (p>0.05). Conclusion: The reduction in CFU/mL of E. faecalis was comparable in both groups. Thus, 3.8% SDF can be used as an alternative root canal irrigant to 2% CHX.

Effect of Deficit Irrigation on Maize (Zea Mays L.) Crop Under Conventional, Fixed, and Alternate Furrow Irrigation for Effective Irrigation Water Management

A study was conducted with the objective of determining the effect of deficit irrigation on maize (Zea mays L.) under conventional, fixed, and alternate furrow irrigation. The experiment was conducted at Jimma Agricultural Research Center (JARC) in 2014/2015 and 2015/2016 dry periods. Nine treatments of different deficit irrigation levels were factorial combined and randomized in plots, and all cultural practices were done. The crop water requirement was calculated using the CROPWAT8.0 program. Yield and growth parameter data were recorded, and analyzed using SAS software. The two-year over-all statistical analysis result showed that, different deficit irrigation levels had a significant effect (p<0.05) on grain yield, ear height, fresh biomass, 100 seed weight, girth, and water productivity. However, there was no significant effect (p > 0.05) on plant height and internode length. The result revealed that 100% ETc conventional furrow gave the highest grain yield (106.1 Qun/ha), followed by 75% ETc conventional furrow (101.23 Qun/ha) and 50% ETc conventional furrow (81.86 Qun/ha). The minimum yield of 55.64 Qun/ha was obtained at a fixed 50% furrow irrigation, and there was a 52.44% yield improvement. The maximum fresh biomass of 196.5 Qun/ha was obtained from 100% conventional furrow, and the minimum 103.40 Qun/ha was at 50% fixed furrow irrigation. The maximum and minimum water productivity of 8.007 and 2.8 kg/m3 were obtained at 75% conventional and 100% fixed furrow irrigation, respectively. Considering the water productivity, net economic benefit and sustainable production of the crop in the agroecology of the study area, combination of 55% up to 85% of deficit irrigation level with conventional furrow irrigation system could be recommended for the production of maize in a deficit furrow irrigation method. Based on the observations made and the statistical analysis done, fixed furrow irrigation was not recommended for the study area.

Irrigation Response, Water Use, and Lint Yield of Upland Cotton Cultivars

Highlights In-season crop water use and canopy temperatures after first square did not differ among cultivars. Lint yield was significantly affected by cultivar in all study years. Cultivar effects on lint yield were significant only at higher irrigation levels. Crop water productivity increased with increasing irrigation in two of the three study years. Abstract. Upland cotton (Gossypium hirsutum L.) production requires less irrigation compared with other crops and thus provides an opportunity to reduce risk and maintain profitability in areas where water is limited. Water use, canopy temperature, lint yield, and crop water productivity were evaluated for four early to medium maturity upland cotton cultivars under three levels (100%, 66%, and 33%) of alternate furrow subsurface drip irrigation (SDI) in a thermally limited environment. Crop evapotranspiration (ET) across cultivars and years averaged 627, 547, and 467 mm for the 100%, 66%, and 33% irrigation levels, respectively, and did not differ among cultivars (P > 0.05). Changes in stored soil water within each irrigation level were similar among cultivars, with significant differences occurring infrequently. Measured canopy temperatures from first white flower to two weeks after cutout did not significantly differ among cultivars (P > 0.10) within each irrigation level. Crop water use during boll maturation, as inferred from the developed crop coefficient curve, was considerably less than reported by other studies, signifying that irrigation could be terminated earlier without reducing lint yield. The cultivar effect on lint yield was significant in all study years (P < 0.001), but only at the 66% and 100% irrigation levels, with one cultivar exceeding the average yields of all evaluated cultivars by 13% across the three study years. Medium maturity cultivars usually yielded less than early maturity cultivars, especially for a year with less accumulation of thermal energy. Crop selection and late season irrigation water management were both key to improving cotton water productivity. Keywords: Upland cotton, Subsurface drip irrigation, Water productivity, Root water uptake, Canopy temperature.

IRRIGATION PROCEDURE (MODE) OF TOMATO GROWN BY THE LOW PRESSURE DRIP IRRIGATION METHOD

Presently, the Republic of Kazakhstan, particularly the Kyzylorda region, grapples with a significant water scarcity issue. In light of this, the utilization of the drip irrigation method plays a crucial role in the judicious management of water resources. In regions like Kyzylorda, characterized by pronounced drought conditions, the efficacy of employing a low-pressure drip irrigation system is notably high. This approach results in an augmented land utilization coefficient, savings in material and labor costs, and an enhanced efficiency in the utilization of irrigation water. The implementation of a drip irrigation system contributes to the improvement of soil nutrition, air circulation, and water-physical properties. It mitigates soil erosion risks, ensures optimal water utilization by supplying irrigation water directly to the roots of each plant, and thereby maximizes the plants' water utilization efficiency. The likelihood of achieving abundant, excellent, and consistent harvests from agricultural crops rises. This method offers several advantages compared to alternative irrigation techniques, including reduced labor costs, preservation of the soil's fundamental structure, prevention of surface soil folds, the ability to concurrently apply fertilizers to the root system area, a potential 30-100% increase in crop productivity, a 50-60% decrease in irrigation water usage, and suitability for use in areas with high slopes.

Automated Safe AWD Rice Irrigation Scheduling using Low-Power WAN Technology

Farmers in a particular area of the Southern Philippines have confirmed that droughts have affected their rice farms, compelling them to lessen their cropping annually until enough water resources become available. This influenced them to seek alternative irrigation techniques. This study creates a system that implements an alternate wetting and drying technique-based irrigation scheduling to cover a whole rice cropping season through water level and soil moisture sensing. The system is available to three rice growth varieties; short, medium, and long. System development includes implementing SMS for notification, a low-power wide area network, and utilizing an IoT dashboard for data visualization.

Impacts of long-term irrigation with coalmine effluent contaminated water on trace metal contamination of topsoil and potato tubers in Dinajpur area, Bangladesh

Rapid depletion of groundwater and climate change mediated shifting precipitation pattern is forcing farmers to look for alternative irrigation options like wastewater. However, routine irrigation with trace metal contaminated wastewaters could potentially pollute soil as well as cause health risks through the consumption of food products grown in contaminated soil. Thus, the present study aimed to investigate the trace metals build-up status in topsoil and potato (Solanum tuberosum L.) tubers upon continuous irrigation with coalmine effluent contaminated wastewater compared to irrigation with groundwater and surface water over three consecutive years. Soil pollution status and human health risk associated with consumption of potato tubers grown on wastewater-irrigated soil was also assessed in this study. Three separate experimental sites differing in irrigation source (groundwater, surface water, and coalmine wastewater) were selected near Barapukuria Coal Mining Company Limited located at Parbatipur upazilla of Dinajpur district, Bangladesh. Nine trace metals namely arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) were estimated. Results showed significantly higher trace metal content in both soil and potato tubers due to wastewater irrigation. Wastewater suitability for irrigation regarding Cd, Cr, Cu, Fe, Ni and Pb were off the permissible level although the soil contamination with trace metals and their levels in potato tubers remained within the safety limit. Health risk assessment revealed that, consumption of potato tubers grown in wastewater-irrigated soil remained safe although health risk associated with Cr was almost at the border. The study exclusively highlighted the core massage that, trace metal contamination of both soil and potatoes cultivated in them was increasing alarmingly due to three years of wastewater-irrigation. Although the extent of contamination was below critical limit, it can potentially become hazardous in years to come unless wastewater-irrigation is checked. This study was successful to provide valuable insights regarding the potential environmental and human health threats that might arise due to unmindful irrigation of contaminated coalmine wastewater. Besides, this study should prove useful in strategizing safety measures for cropping under trace metal contaminated soils and for planning industrial effluent disposal to avoid agricultural soil contamination.

Comparison of EDTA and Boric Acid Irrigation in Terms of Root Canal Dentin Microhardness and Sealer Penetration Depth

Chemo mechanical preparation is one of the important stages for successful endodontic treatment, and Boric acid has been proposed as an alternative irrigation solution for root canal treatment. Objective: The purpose of this study was to evaluate the effect of irrigation with boric acid (BA) and EDTA on the mineral content and microhardness of dentin and penetration of the AH Plus root canal sealer. Methods: 63 single-rooted teeth were instrumented. Microhardness analysis, 45 teeth were cut longitudinally and then transversely to obtain dentin. Pre- and post-treatment microhardness values were measured. The samples were randomly assigned into 3 groups (n = 15) for irrigation solution: distilled water, 17% EDTA, and 5% BA. The 18 roots were irrigated with three solutions (n = 6). Nine of the roots were filled with AH-Plus for confocal laser scanning microscopy analysis, and the others were used for XRD analysis. Results: The results were evaluated with the ANOVA test. BA caused a significant decrease in microhardness value in apical and coronal parts (p < 0.05), while EDTA reduced only in coronal parts (p < 0.05). Conclusion: BA provided higher sealer penetration ability. BA reduced the microhardness and provided better sealer penetration.

The Effect of Irrigation Techniques on Sustainable Water Management for Rice Cultivation System - A Review

Rice serves as a fundamental sustenance for approximately half of the global population, particularly in Asia. Nevertheless, the cultivation of rice demands a substantial water supply, and the challenges associated with water deficits have been exacerbated by irregular rainfall patterns induced by global warming. Consequently, there is a critical need to reassess irrigation techniques to effectively tackle these issues. In this comprehensive review, the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) method was employed to systematically explore literature on irrigation techniques aimed at fostering sustainable water management in rice cultivation systems. The primary components of the framework encompass water consumption and water-related characteristics, soil-related characteristics, and plant-related characteristics, encompassing relevant components and indicators. Two alternative irrigation methods, namely alternate wetting and drying (AWD) and saturated soil irrigation (SSI), have been proposed to enhance water use efficiency (WUE) in rice cultivation compared to traditional continuous flooding (CF). These alternative irrigation methods do not adversely affect rice yield, both quantitatively and qualitatively. Furthermore, these alternative irrigation approaches have the potential to mitigate greenhouse gas (GHG) emissions, particularly methane emissions, in rice production. This review underscores the significance of data on alternate irrigation systems, providing valuable insights for researchers and policymakers in formulating strategies that align at every level for practical implementation. This is crucial as it is relevant to multiple organizations and stakeholders. Moreover, in the face of inclement weather conditions resulting from climate change, the study's findings indicate that research on farmers' adaptation, plant stress, and resilience within the rice cultivation system is still in its nascent stages. This highlights the pressing need for further exploration and advancement in these areas to develop effective strategies for coping with the challenges posed by climate change.

Antibacterial Irrigation Solution Cocoa Bean Cuticle Extract (Theobroma cacao L) Against Streptococcus viridans

Background: Pulp necrosis is the demise of the pulp due to persistent infection in the pulp area, such as Streptococcus viridans. Irrigation steps during biomechanical preparation and sterilization play a very important role. The irrigation material often used is 2.5% NaOCl because it has a broad antibacterial spectrum but is irritating and has an unpleasant aroma. The cuticle of cocoa beans (Theobroma cacao L.) might be an alternative root canal irrigation material. The Objective: To determine the antibacterial properties of irrigation solution of cocoa bean cuticle extract against Streptococcus viridans. Materials and Methods: This study was laboratory experimental with a post-test-only control group design by calculating the number of bacterial colonies. Consisting of eight research groups, namely cocoa bean cuticle extract with concentrations of 25% (P1), 12.5% (P2), 6.25% (P3), 3.12% (P4), 1.56% (P6), 0.78% (P6), NaOCl 2.5% (K+), and sterile distilled water. 0.5 ml of each group was taken and then mixed with 0.5 suspension of Streptococcus viridans, diluted 10-4. Next, the extract and bacterial suspension mixture 10-4 were incubated for 24 hours, then 0.1 ml was inoculated on BHIA media and incubated. After that, the colony counter manually counted the number of colonies. Results: The result showed a significance of p<0.5, followed by the Mann-Whitney test, which showed significant differences except in group P1 (25%) with K+ (NaOCl 2.5%). Conclusion: Cocoa bean cuticle extract irrigation solutions with concentrations of 25%, 12.5%, 6.25%, 3.12%, 1.56% and 0.78% presented antibacterial power against Streptococcus viridans. Keywords: Streptococcus viridans, Antibacterial, Cocoa bean epidermis extract, Irrigation solution.

A 15N-Tracing Study to Explore the Coupling Effects of Biochar and Nitrogen Fertilizer on Tomato Growth, Yield, Nitrogen Uptake and Utilization, and the Rhizosphere Soil Environment under Root-Divide Alternative Irrigation

To investigate the coupling effects of biochar and nitrogen fertilizer on tomato growth, nitrogen uptake and utilization (NUU), and the soil environment, a pot experiment was conducted using 15N-tracing technology from March to July 2021 and from September 2021 to January 2022. Three biochar application rates (B0, B1, and B2; 0, 3, and 6 t/hm2, respectively) and three nitrogen levels (N1, N2, and N3; 150, 300, and 450 kg/hm2, respectively) were set up. The results show that the growth, yield, rate of 15N uptake, nitrogen derived from soil (Ndfs), total nitrogen (TN), 15N utilization, and recovery rate of tomatoes were improved under biochar application, but nitrogen derived from fertilizer (Ndff) gradually decreased. A Pearson correlation analysis showed that the 15N uptake, Ndfs, TN, rhizosphere soil organic matter, soil organic carbon, and TN were significantly positively correlated with the yield and lycopene content of tomatoes. The comprehensive benefit to the tomatoes was evaluated based on combination weighting with the help of the technique for order preference by similarity to ideal solution (TOPSIS). This indicates that the best planting mode was the B2N2 treatment, with a biochar rate of 6 t/hm2 and nitrogen levels of 300 kg/hm2, under the alternative partial root-zone irrigation.

The Effect of Adding Poly-γ-Glutamic Acid (γ-PGA) on the Moisture Content of Gypsiferous Soil Under Partial Drip Irrigation System

The alternate partial root-zone irrigation APRI is a modern irrigation method to save irrigation water. A field experiment was conducted to study the effect of the conventional irrigation(CI) system and the APRI system, using different levels of poly-γ-glutamic acid (γ-PGA) (0, 15, 30, 60, and 120) kg ha-1 in Gypsiferous Soil, on soil moisture content and water use efficiency. The APRI method achieved the best water extraction efficiency of 3.25 kg.m-3. The depths of water added in the traditional irrigation method were (435.58, 420.52, 416.71, 410.98, and 398.67) mm, and in the alternating irrigation method, they were (390.42, 370.50, 361.27, 340.40, and 322.40) mm for the additional levels of (γ-). PGA), respectively. The APRI method achieved an abundance of irrigation water compared with the CI of (11.57, 13.50, 15.35, 20.74, and 23.66)% for the different addition levels of (γ-PGA), respectively. The decrease in moisture content with the increase in the applied water voltage. There is a direct relationship between the amount of water available to the plant and the level of addition of (γ-PGA).

Antimicrobial efficacy of sodium hypochlorite and hyper-pure chlorine dioxide in the depth of dentin tubules in vitro

ObjectivesThe study aimed to compare the antibacterial effect of a novel disinfectant, hyper-pure chlorine dioxide (hClO2) to sodium hypochlorite (NaOCl) in various depths of dentin tubules.Materials and methodsThe distal root of the extracted lower molars was infected artificially with Enterococcus faecalis. The control group was rinsed with saline, and the test groups were irrigated with either 5% NaOCl or 0.12% hClO2. The longitudinally split teeth were stained by viability stain. The coronal third of the root was scanned with a confocal laser scanning microscope. The fluorescent intensities were measured, and the percentage of dead bacteria was calculated at depths up to 950 μm along the dentin tubules. The effect of penetration depth, irrigants, and their interaction on antimicrobial efficacy was determined by the linear mixed model.ResultsThe percentage of dead bacteria was higher both in the NaOCl (45.1 ± 2.3%, p < 0.01) and in the hClO2 (44.6 ± 3.8%, p < 0.01) irrigant groups compared to saline (23 ± 4.5%); however, there was no difference between them. The percentage of killed bacteria was not correlated with the depths in any group (p = 0.633).ConclusionsOur results suggest that the functional penetration depth of NaOCl is at least 2–3 times more than published to date. There is no difference in disinfection effectiveness along the dentin tubules between NaOCl and hClO2 until at least the measured 950 μm. However, both were only able to eradicate the intratubular bacteria partially.Clinical relevanceHyper-pure ClO2 could be used as an alternative or final adjuvant irrigant in endodontic treatment.

Comparative evaluation of effect of nisin-incorporated ethylenediamine tetraacetic acid and MTAD on endodontic biofilm eradication, smear layer removal, and depth of sealer penetration.

To comparatively evaluate the nisin-incorporated ethylenediamine tetraacetic acid (N-EDTA) and MTAD on cytotoxicity, endodontic biofilm eradication potential, smear layer removal ability, and sealer penetration depth. N-EDTA was prepared and characterized using high-performance liquid chromatography (HPLC). Minimum inhibitory, minimum bactericidal, and minimum biofilm inhibitory concentration (MBC, MIC, and MBIC) were determined on Enterococcus faecalis (E. faecalis) strain. The cytocompatibility of N-EDTA and MTAD was evaluated using 3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-based colorimetric assay. Dentin specimens (n = 88 for antibacterial analysis, n = 170 for sealer penetration depth) were prepared and subjected to the classical irrigating strategy and obturation, respectively. The scanning electron microscopic evaluation (SEM) was done for the evaluation of biofilm disruption and smear layer removal. Confocal laser scanning microscopy (CLSM) evaluation was done for determining percentage of bacterial viability and sealer penetration depth. Statistical analysis of one-way ANOVA and Tukey's HSD post hoc tests for bacterial viability and Kruskal-Wallis test and Mann-Whitney test for smear layer removal and depth of penetration were done with the significance level set at p < 0.05. MTAD and N-EDTA showed cytocompatibility without any statistical differences from each other. For N-EDTA, the MIC and MBC values were 12.5 μg/ml (1:8), and MBIC values were 36 μg/ml. Biofilm disruption and killed bacterial percentage of N-EDTA was statistically higher than MTAD, whereas both the materials showed similar efficacy in the removal of the smear layer and sealer penetration depth. N-EDTA had negligible cytotoxicity with similar smear layer removal ability, sealer penetration, and better antibiofilm potential than MTAD. N-EDTA can serve as a viable alternative endodontic irrigant.

THE ANTIBACTERIAL EFFECT OF ROSEMARY (ROSMARINUS OFFICINALIS L.) ON ENTEROCOCCUS FAECALIS BACTERIA AS AN ALTERNATIVE FOR ROOT CANAL IRRIGATION

Background: Root canal treatment is one of the endodontic treatments to preserve teeth with bacterially infected pulp tissue. Root canal irrigation is one of the most important processes to eliminate bacteria in root canals. In the root canals of teeth with failed endodontic treatment, Enterococcus Faecalis bacteria were found, so that alternative irrigation materials were needed that were more effective.Purpose: The aim of this study was to explain the effect of the antibacterial power of rosemary (Rosmarinus officinalis L.) on Enterococcus faecalis bacteria.Methods: The samples tested were 24 in the form of Enterococcus faecalis bacteria culture in BHI agar media in petri dishes. This research uses the well method. Each 1 petri dish was divided into 4 wells and each was given rosemary extract (Rosmarinus officinalis L.) at 5% and 10% concentrations, as well as a positive control (NaOCl 2.5%). Bacteria were grown and incubated, then diluted with 0.5 McFarland standard. (1.5X108 bacteria permilliliter).Results: The average inhibitory power of Enterococcus faecalis in rosemary (Rosmarinus officinalis L.) extract at 5% concentration was 16.7 mm and at 10% concentration was 18.8 mm, while in 2.5% NaOCl solution it was 8 mm. The hypothesis test has a value of p = 0.000 (p &lt; 0.05).Conclusion: Rosemary extract (Rosmarinus officinalis L.) has a more effective inhibition of Enterococcus faecalis bacteria.

Assessment of Soil Water Dynamics and Yield Response of Broccoli Under Subsurface Drip Irrigation in the Semi-Arid Region of India

ABSTRACT A field experiment was conducted to investigate the optimum lateral spacing and irrigation frequency of a subsurface drip irrigation system for broccoli crop grown in the semi-arid region of Haryana (India). The effects on soil water dynamics, growth parameters (i.e. plant height, leaf length, no. of leaves/plant, curd weight and curd diameter), irrigation water use efficiency (IWUE), fertilize use efficiency (FUE) and yield response of broccoli were assessed under two lateral spacings (45 cm and 60 cm) and four irrigation frequencies (daily, and after one, two & three days) in the years of 2019–20 and 2020–21. The results show that soil moisture content was higher near the dripper, and it decreased with increasing radial distance from the drippers. Further, the moisture content was high at 45 cm lateral spacing as compared to 60 cm lateral spacing. The effects of selected treatments on growth and yield parameters were found significant and maximum broccoli yield (147. 41 q ha−1) was found at 45 cm lateral spacing with alternate days of irrigation. The highest IWUE and FUE of 9.93 kg/m3 and 30.68 kg/kg, respectively, were also found at alternate days irrigation with 45 cm lateral spacing. It may be concluded from the present study that alternate days irrigation with 45 cm lateral spacing is the best choice to obtain the maximum yield of broccoli grown in winter season in the semi-arid region of India.

Field study of irrigation strategies with treated wastewater and saline water on heavy metal accumulation in barley grain.

This study examines the effects of three irrigation regimes with a combination of saline water and treated wastewater on the accumulation of heavy metals in barley grains. A field experiment was designed as a split-split plot arrangement in a randomized complete block design, in which treatments were different irrigation regimes (50%, 70%, and 100% full irrigation) and irrigation water types (saline water [SW], treated wastewater [TW], mixed water resources [MWR], and alternative irrigation [AI]). After cultivation and harvesting of the barley crop, the grain yield, 1000-grain weight, and contents of heavy metals in the grains were measured. The grain yield was enhanced by TW alone, MWR, and AI to 12.8%, 5%, and 9.5% under 70%-deficit irrigation; and 58.3%, 21.7%, and 8.7% under full irrigation, respectively. Based on the guidelines for safe limits of heavy metals in edible plants and livestock feed, the barley grains were safe for livestock and toxic for humans. The trend of heavy metal contents in the grains was Fe > Zn > Pb > Cu ≥ Cr > Cd. Irrigation with SW compared with TW increased Fe, Cu, Zn, Pb, Cd, and Cr contents in the grains to 11.75%, 10.97%, 5.22%, 19.15%, 3.45%, and 9.21%, respectively. The amounts of toxic elements of Cd and Pb were maximized by using MWR, whereas the Cr content in the grain was maximized by using AI. There were no significant difference in the metal uptake by the grains among all irrigation regimes in any irrigation water resource. However, compared with the other irrigation regimes, the full irrigation resulted in lower Zn, Cu, and Cd contents, whereas the 50%-deficit irrigation led to lower Pb and Cr contents in the grains. Therefore, irrigation with TW is recommended based on the grain yield, whereas AI is suggested due to lower Cu, Pb, and Cd contents in the grain, and MWR is recommended due to lower Cr content. Furthermore, full and 50%-deficit irrigation regimes are recommended to, respectively, maximize grain yield and minimize the toxic metal contents in the grain. PRACTITIONER POINTS: Mixed saline water and treated wastewater and alternative irrigation enhanced grain yield. Saline water versus treated wastewater increased the grain heavy metal contents. Alternative irrigation decreased Fe, Cu, Pb, and Cd amounts in the grain. Grain Cu content had strong relationship with irrigation regime. 50%-deficit irrigation minimized Pb and Cr contents in the grain.

Evaluation of Furrow Irrigation System on Head Cabbage Yield and Water Use Efficiency in Arbegona Woreda, Ethiopia

Available fresh water resources are subjected to an ever-increasing pressure due to extensive agricultural water demand for irrigated lands. A long-term perspective in shortage of fresh water resources, especially in arid and semi-arid area, highlights an urgent solution for innovative irrigation strategies and agricultural water management. The experiment was conducted in Arbegona district, Sidama region of Ethiopia. This experiment was conducted to evaluate and demonstrate of Alternative, Fixed and Conventional furrow irrigations on Head Cabbage yield and water use efficiency. To achieve this objective the treatment were three furrow irrigation method (Conventional, Alternate and Fixed furrow) laid out in a random complete block design (RCBD) with three replications. The result shows that there is no significant difference between alternative and conventional furrow irrigation on Head cabbage yield. But, fixed furrow irrigation system reduces the yield significantly. The maximum yield (48407kg/ha and 43840kg/ha) was obtained from conventional and alternate furrow irrigation method, respectively. The minimum yield (35242kg/ha) was obtained under fixed furrow irrigation. Furrow irrigation method has no significant effect on plant height, head weight and head diameter of head cabbage. The highest water use efficiency was obtained from alternate furrow irrigation and shows significant difference between the other treatments. Therefore, to save water, labour and time without significant yield reduction alternate furrow irrigation is recommended in water scarce area of Ethiopia.

Improved yield-salinity relationship considering salt and root distribution dynamics

Alternate drip irrigation of brackish and freshwater (ADI) is an effective strategy to relieve salt stress in crops and increase crop yield compared to irrigation using only brackish water (B). However, the correlation between the soil salinity as well as maize root distribution dynamics and crop yields under ADI treatment remains unknown. A three-year field experiment under ADI treatment was carried out from 2019 to 2021 to evaluate the effects of irrigation using only freshwater (F), B, or both brackish and freshwater (1B1F, 2B1F, 3B1F; after irrigating with brackish water once, twice, and thrice including alternate irrigation with freshwater) on root growth and crop yield. This study aimed to capture the dynamics of the electric conductivity of a saturated paste extract (ECe) and root length density (RLD) at different soil depths during different crop growth periods under different ADI treatments. Moreover, to unravel the two-dimensional distribution of soil salt and root growth in the soil profile, ECe and RLD in the area under plastic film mulching (the mulched area) and the no mulching area (bare area) were measured. This study also evaluated the yield-salinity relationship using salt and root distribution dynamics (Y-SI) and the response of maize crops on ECe and RLD. The result of this study demonstrated that the estimation accuracy of the Y-SI was higher than the yield-salinity relationship by the Food and Agriculture Organization of the United Nations. MRE decreased by 4.9% for the Y-SI using ECe and RLD with eight positions (Y-SI 8) compared to only one position (Y-SI 1). The salt stress level decreased with increasing soil layer, specifically in the 0–40 cm soil layer in mulched area. The higher irrigation frequency of brackish water was associated with a higher ECe, longer salt stress duration, lower RLD during the last two growth stages, and a lower maize yield. Compared with F treatment, average ECe in the 0–40 cm soil layer under 1B1F, 2B1F, 3B1F, and B treatments increased by 22.7%, 30.6%, 35.1%, and 46.5%, average proportion of high salt stress (>3.8 dS m−1 for ECe) duration increased by 8.9%, 16.9%, 21.0%, and 26.4%, average RLD decreased by 6.6%, 16.9%, 21.7%, and 26.9%, and average relative maize yield decreased by 1.9%, 4.9%, 12.2%, and 16.1%, respectively. In general, the 2B1F treatment could be recommended as the optimal irrigation strategy with a reduction of 1800 t ha–1 for freshwater irrigation compared to the B treatment, but only a 4.9% decrease for maize yield compared to the F treatment.

Optimization of Irrigation of Wine Grapes with Brackish Water for Managing Soil Salinization

Water scarcity and quality are critical impediments to sustainable crop production. In this study, HYDRUS-2D was calibrated using field measurements of water contents and salinities in the soil under wine grapes irrigated with river water (Rw, 0.32 dS/m). The calibrated model was then used to evaluate the impact of (a) four different water qualities ranging from 0.32 (Rw) to 3.2 dS/m (brackish water, Gw) including blended (Mix) and monthly alternating (Alt) irrigation modes; (b) two rainfall conditions (normal and 20% below normal); and (c) two leaching options (with and without 30 mm spring leaching irrigation) during the 2017–2022 growing seasons. Irrigation water quality greatly impacted root water uptake (RWU) by wine grapes and other water balance components. Irrigation with brackish water reduced average RWU by 18.7% compared to river water. Irrigation with blended water or from alternating water sources reduced RWU by 8.8 and 7%, respectively. Relatively small (2.8–8.2%) average annual drainage (Dr) in different scenarios produced a very low (0.05–0.16) leaching fraction. Modeling scenarios showed a tremendous impact of water quality on the salts build-up in the soil. The average electrical conductivity of the saturated soil extract (ECe) increased three times with Gw irrigation compared to Rw (current practices). Blended and alternate irrigation scenarios showed a 21 and 28% reduction in ECe, respectively, compared to Gw. Irrigation water quality substantially impacted site-specific actual basal (Kcb act) and single (Kc act) crop coefficients of grapevine. Threshold leaching efficiency estimated in terms of the salt mass leached vs. added (LEs; kg/kg) for salinity control (LEs &gt; 1) was achieved with LFs of 0.07, 0.12, 0.12, and 0.15 for the Rw, Mix, Alt, and Gw irrigations, respectively. Applying annual leaching irrigation (30 mm) before bud burst (spring) in the Mix and Alt with Rw and Gw scenarios was found to be the best strategy for managing irrigation-induced salinity in the root zone, lowering the ECe to levels comparable to irrigation with Rw. Modeling scenarios suggested that judicious use of water resources and continuous root zone monitoring could be key for salinity management under adverse climate and low water allocation conditions.

Annual greenhouse gas emissions from a rice paddy with different water-nitrogen management strategies in Central China

Current water-nitrogen (N) management strategies are necessary to be improved to increase crop productivity while reducing environmental costs. However, the effects of improved water-N management strategies on paddy CH4 and N2O emissions simultaneously generated during the growing and non-growing seasons have not been explored. Therefore, in this study, four water-N management practices—urea plus conventional irrigation (UREA+CI), urea plus alternate wetting-drying irrigation (UREA+AWD), controlled-release N fertilizer plus CI (CRNF+CI), and CRNF plus AWD (CRNF+AWD)—were evaluated in a 3-year field experiment following a randomized complete block design with three replications each. The results demonstrated that during rice growing seasons, CH4 emissions significantly decreased by 12.6–44.9% under UREA+AWD and by 17.2–32.1% under CRNF+CI, compared to UREA+CI, respectively, and CRNF+SWD showed the highest mitigation potential. N2O emissions were reduced in CRNF treatments (CRNF+CI and CRNF+AWD) but increased by replacing CI with AWD during rice growing seasons, suggesting the potential effects of water regimes on N2O emissions. Furthermore, AWD and CRNF reduced CH4 emissions during the land preparation period before the late rice growing season and the fallow period, whereas CRNF treatments triggered the release of N2O in the fallow period. Moreover, there were no significant differences in soil organic carbon sequestration rates among the treatments. The results indicated that AWD, CRNF and their combination significantly reduced annual net total greenhouse gas emissions without yield loss. Collectively, this study unravels the potential of alternative water-N management strategies to improve rice yields while minimizing GHG emissions in double rice cropping systems.