Irrigation Methods Research Articles

Increased stability of a subtropic bamboo forest soil bacterial communities through integration of water and fertilizer management compared to conventional management.

Conventional management (CM), substantial fertilization and flooding irrigation, hasled to soil acidification, the decrease in soil bacterial diversity in bamboo forests. Integration of water and fertilizer management (IWF) can effectively improve the efficiency of water and fertilizer use, but its effect on soil environment, especially on microbial community, is still unclear. Here, we used next-generation high-throughput sequencing to compare soil properties and bacterial communities through different fertilization and irrigation methods under IWF and CM. Compared to the control group, CM significantly reduced soil pH and bacterial diversity, while IWF improved soil nutrition status, increased soil bacterial diversity and soil pH to a level similar to the control group. Compared with CM, IWF also improved the relative abundance of beneficial bacteria and copiotrophic bacteria community in the soil, and the bacterial community in IWF was similar to CK. The structure of the bacterial community was also significantly correlated with soil organic matter, total nitrogen, hydrolyzable nitrogen, and available potassium, while soil bacterial diversity was mainly associated with soil hydrolyzable nitrogen. IWF can play an important role in preventing soil acidification, the loss of soil bacterial diversity, and improving the structure of the bacterial community under specific conditions.

Enhancing Okra Growth and Yield Through Foliar Nutrient Application in Conjunction with Mulching and Drip Irrigation

Background: Okra (Abelmoschus esculentus) is an important vegetable crop that belongs to family malvaceae and is grown both in tropical and subtropical regions of India. In north-coastal Andhra Pradesh, okra is cultivated frequently so, optimizing the nutrient management practice is an efficient method for increasing yield. Among those practices, foliar fertilizers, mulching and irrigation methods are essential in maximizing the yield and quality of okra. Therefore, the present investigation deals with the combined effects of foliar nutrients, mulching and irrigation methods, providing valuable data for sustainable okra production in a particular area. Methods: The present investigation was conducted during June to September 2023, with seven different treatments using randomized block design. This experiment mainly focuses on combinations of mulching and foliar sprays of 19:19:19 and 13:0:45 at different concentrations. Collected data were analyzed using ANOVA and fisher’s least significant difference test at a 5% significance level. Result: Among all the treatments, 100% RDF along with the foliar application of 19:19:19 @ 1.0% + 13:0:45 @ 2% at 30, 45 and 60 days after sowing has proven the best treatment, where it recorded the highest yield of 101 q per hectare (Q/ha) due to the application of sufficient nutrients. Whereas, the lowest yield was recorded with control plot due to insufficient nutrient supply in relation to growth and yield parameters.

Yield Gap Analysis in Adoption of Production Technology and Economics of Coconut at Farmers Field of Tumkuru District, India

The study was conducted with analysis of yield gap in adoption of production technology and economics of coconut through frontline demonstrations(FLD) at farmer’s field of Tumkur district, Karnataka state during the year from 2017-18 to 2019-20.The demonstrated plot yield obtained through frontline demonstrations was higher (9,932 nuts/ha) than the actual yield obtained by the farmers on their farm under own management practices (7,852 nuts/ha), but lower than the potential yield of coconut (12,300 nuts/ha).The data revealed that the total yield gap between potential yield and actual yield of coconut was 36.16 per cent, in which 20.92 per cent of yield gap between demonstration plot and actual farmers plot yield and 19.25 per cent of technological gap. The maximum number of coconut growers adopted intercropping system (90.00 %) followed by irrigation method (86.66 %), whereas lesser adoption of harvesting of coconuts by coconut climber (26.67 %). More number of farmers were found to increase in adoption per cent of growing of green manure crops & incorporation (56.67 %) and soil sample analysis from coconut plot (53.33 %) and also improved soil fertility status of demonstrated plot as compared to farmers practices. There was significantly increased the yield of coconut (26.49%) after conducted the frontline demonstrations. The gross return, net return and B:C ratio was also found to increased in demonstrated plots as compared to farmers’ practice. The adoption of different production package of practices in coconut shows positive impact on yield and economics of coconut through adoption of demonstrated technology.

Investigating the effects of various irrigation methods on bacterial communities in paddy soil

Different irrigation methods can impact the micro-ecological environment of paddy soil, affecting crop growth. This study focuses on County A, a key grain production area on China’s East Coast, where 20 plots each of intermittent and flood irrigation were selected and labeled as Group I and Group F, respectively. Soil's basic physicochemical properties and heavy metal content were measured in the laboratory, and high-throughput sequencing was used to analyze soil bacterial communities. The study evaluated the impact mechanisms of different irrigation methods on these bacterial communities. Results indicate: (1) Intermittent irrigation significantly increased bacterial richness, evenness, and diversity, enhancing microbial community diversity and stability. (2) Intermittent irrigation notably raised the abundance of 9 bacterial genera (e.g., Nitrospira, H16) while reducing the abundance of 7 genera (e.g., Geobacter, Sphingomonas). (3) The soil environment in Group I was stable, with bacterial communities influenced by SMC, pH, and Cu; Group F was affected by multiple environmental factors. Intermittent irrigation provides a stable environment that supports bacterial diversity and abundance, contributing to a richer community structure. (4) Intermittent irrigation optimizes moisture, significantly enhancing bacterial functions such as energy production, cell wall biosynthesis, repair, and signal transduction. These findings suggest that intermittent irrigation improves bacterial community stability and diversity, which is crucial for enhancing the overall quality of paddy fields.

Comparison of the safety of flexible ureteroscopy with the different irrigation methods in a 3D print kidney model.

To compare intrarenal pressure (IRP) and irrigation flow by varying suspended water heights and hand-held pressure pumping during flexible ureteroscopy using an in vitro 3D printed kidney model. A 3D-printed silicone model was used to simulate the kidney. The ureteral access sheath(UAS) was connected to the kidney model and positioned at the ureteropelvic junction. Central venous pressure tubing was used to monitor the pressure in the renal pelvis under different conditions. Sheath sizes of 12Fr and 14Fr were tested with flexible ureteroscope (fURS) sizes of 7.5, 8.5, and 9.5Fr, respectively. The irrigation was gravity-based, with suspended water heights set at 60, 90, 120, 150, and 180cm. The manual pumping as another set of measurement is used to measure the maximum intrarenal pressure. Using a 12Fr sheath with a 9.5Fr fURS loading without additional accessories resulted in IRP ranging from 8.4 to 17.5 cmH2O, while manual pumping perfusion pressure exceeded 60 cmH2O. Loading a 200-um laser fiber reduced the pressure to 6.4-10.5 cmH2O, and using a stone basket decreased it to 4.0-5.0 cmH2O. Using a 14Fr sheath with a 9.5Fr fURS resulted in an IRP of 2.5-6.0 cmH2O, compared to 17 cmH2O with manual pumping. With a 12Fr sheath and a 7.5Fr fURS, the IRP ranged from 5.4 to 8.2 cmH2O, while manual pumping resulted in 25.5 cmH2O. With a 14Fr sheath and a 7.5Fr fURS, the IRP ranged from 1.5 to 4.3 cmH2O, and manual pumping resulted in 9.0 cmH2O. When using a UAS in a flexible ureteroscopy, the IRP can be maintained within a safe range with different fURS/UAS combos with a suspended water height of less than 180cm. However, with specific fURS/UAS(9.5Fr/12Fr) combos, the IRP exceeded the safe limit when using manual pumping. Gravity irrigation with a suspended water height of less than 180cm is safe in this simulated clinical environment.

Combined Effects of Magnetized Irrigation and Water Source on Italian Lettuce (Lactuca sativa L. var. ramosa Hort.) Growth and Gene Expression

Agricultural water scarcity has become a global issue. Optimizing irrigation water quality and effectively utilizing non-conventional water resources are essential strategies to alleviate pressure on agricultural water use and achieve sustainable development. This study employed Italian lettuce as the test crop to explore the effects of magnetization treatment (M) at a magnetic field strength of 0.2 T and various irrigation water sources (T) on its growth. The following six treatments were established: fresh water irrigation (M0T1), recycled water irrigation (M0T2), saline water irrigation (M0T3), magnetized fresh water irrigation (M1T1), magnetized recycled water irrigation (M1T2), and magnetized saline water irrigation (M1T3). The results showed that the magnetization treatment increased the electrical conductivity (EC), power of hydrogen (pH), and dissolved oxygen (DO) of the three water sources compared to the non-magnetized treatment. Furthermore, magnetized irrigation with fresh water, recycled water, and saline water increased the contents of nitrogen (N), potassium (K), calcium (Ca), and magnesium (Mg) in lettuce. It also led to increases in the contents of soluble proteins (by 9.27% to 22.25%), soluble sugars (by 13.45% to 20.50%), and vitamin C (VitC) (by 4.18% to 19.33%) in lettuce. Additionally, it enhanced the above-ground fresh weight of lettuce (by 9.36% to 8.81%) and water productivity (WPc) (by 5.85% to 10.40%), while reducing water consumption. Among these treatments, magnetized fresh water irrigation was the most effective in improving quality, fresh weight, and WPc, followed by magnetized recycled water. Gene expression analysis revealed that differentially expressed genes (DEGs) were primarily enriched in metabolic pathways such as the MAPK signaling pathway—plant, phytohormone signaling, and cysteine and methionine metabolism. In summary, magnetized irrigation significantly enhanced DO levels in irrigation water, along with the fresh weight, quality, and WPc of lettuce, demonstrating its effectiveness as an efficient method for agricultural irrigation.

Drip irrigation and mulching reduce weed interference and improve water productivity of spring maize

Abstract Drip irrigation and mulching were tested to minimize unproductive water loss through evaporation and weed interference. A field experiment was conducted during spring season of 2020 and 2021 in split plot design with three replications. The study includes six treatment combinations of drip irrigation methods (surface drip and subsurface drip irrigation) and mulching (black plastic, paddy straw and no mulch) along with one conventional furrow irrigation without mulching (as control) in main plots. Four weed control treatments (atrazine 1000 g a.i./ha as pre-emergence, two hand weedings at 30 and 60 days after sowing [DAS], weed free and weedy for whole crop growth period) were kept in the subplots. The combination of drip irrigation and mulches significantly enhanced leaf area index and crop biomass at 60 DAS than furrow irrigation. Integration of subsurface drip irrigation with plastic mulching resulted in the lowest weed density and biomass among main plots. Drip irrigation coupled with plastic and straw mulching resulted in 86 and 50% reduction in weed density and biomass, respectively, as compared to no mulching. Integration of subsurface drip with paddy straw mulch and black plastic mulch resulted in 17.1 and 15.5% higher maize grain yield, respectively, as compared to furrow irrigation. The highest irrigation water productivity (3.58 kg/m3) was observed in combination of subsurface drip and paddy straw mulch followed by combination of subsurface drip and black plastic mulch (3.51 kg/m3). Overall, straw mulching in drip irrigation system proved economical in terms of maize productivity.

Progress and Hotspot Analysis of Bibliometric-Based Research on Agricultural Irrigation Patterns on Non-Point Pollution

With the constant advancement of irrigation technology and the continuous expansion of irrigation areas, non-point source pollution (NPS) caused by agricultural activities has posed a persistent threat to ecosystems and biological safety. Against this backdrop, it is imperative to lay scientific foundations for green, sustainable, and high-quality agricultural development through a thorough review of the relevant research progress. In this study, bibliometric methods are adopted to comprehensively analyze and visualize the current state and key literature on agricultural irrigation and NPS pollution from 2010 to July 2024. The focus of this study is specifically on summarizing the research hotspots and development trends of different irrigation methods and the mechanisms behind their impacts on NPS pollution. The results indicate that publications from the United States and China account for 63.8% of the total, but the fragmentation of research efforts remains, suggesting a necessity to strengthen international and regional collaboration. There are three institutions with the highest publication output, namely Northwest A&F University, Hohai University, and the Chinese Academy of Sciences. The subjects identified as the key areas of research on irrigation-related NPS pollution (IRR-NPS) include precision irrigation, rapid water pollution response, spatiotemporal management, interdisciplinary integration, wastewater treatment, and crop models. Regarding future research, it is necessary to focus attention on real-time precision irrigation, standardized crop models, data accuracy, spatiotemporal pollution coordination, pollution purification technology development, interdisciplinary integrated governance, and the innovative applications of soil improvement technologies. In addition to offering theoretical support and practical guidance for the management of agricultural NPS pollution, this study also provides management and technical support for policymakers, which is beneficial for advancing agricultural irrigation technology and environmental preservation.

Nitrogen cycling and associated grey water footprint in croplands under different irrigation practices

The pervasive application of nitrogen (N) fertilisers in agriculture poses a significant threat to freshwater ecosystems. The grey water footprint (GWF) is a measure of the volume of freshwater required to assimilate the relative water pollutants resulted from N leaching-runoff processes. The responses of N cycling and associated regional GWF to crop production under different irrigation methods have not been investigated. In this study, the N leaching-runoff rate, N₂O, and NH₃ emissions in croplands and the associated GWF per unit crop yield (UGWF) and annual total GWF (TGWF) of winter wheat-summer maize crop rotations across the Hebei, Shandong, and Henan Region (HSHR) of China were simulated and evaluated at the prefecture level over the 2004–2020 period. Four irrigation scenarios were modelled: furrow, sprinkler, surface drip, and subsurface drip irrigation. The results showed significant spatial and temporal heterogeneity in N leaching-runoff rates and emissions of N2O, and NH3. The N leaching-runoff rates for winter wheat and summer maize ranged from 3.9% to 10.9% and 15.0%–32.3%, respectively. With changing different irrigation methods, N leaching-runoff rates exhibited greater sensitivity than N₂O and NH₃ emissions; this sensitivity was more pronounced in winter wheat than in summer maize. Findings reveal that N pollution is influenced not only by irrigation methods but also by weather conditions, crop-specific rooting characteristics, sowing time, and soil texture. Winter wheat UGWF under the four irrigation methods mostly followed the order of furrow > sprinkler irrigation > surface drip irrigation > subsurface drip irrigation. Conversely, for summer maize, subsurface drip irrigation resulted in a higher UGWF compared to furrow irrigation, mainly due to increased water percolation thus higher N leaching-runoff rate in near-saturated soil with higher rainfall. This result reveals the potential conflict between water-saving irrigation and N pollution control. This analysis underscores the necessity of recognising the combined effects of agricultural management practices on water conservation and environmental safeguarding.

Phosphorus Supply Under Micro-Nano Bubble Water Drip Irrigation Enhances Maize Yield and Phosphorus Use Efficiency.

This study aimed to explore the combined effects of micro-nano bubble water drip irrigation and different phosphorus (P) application rates (P0: 0 kg·hm-2; P1: 86 kg·hm-2; P2: 172 kg·hm-2; P3: 258 kg·hm-2) on maize growth, soil phosphorus dynamics, and phosphorus use efficiency to optimize irrigation and P fertilizer use efficiency. Through a field column experiment, the impact of micro-nano bubble water drip irrigation on maize plant height, stem diameter, leaf SPAD values, biomass, and yield was evaluated. The results showed that (1) irrigation methods significantly affected maize growth indicators such as plant height, stem diameter, and root dry weight. Micro-nano bubble water drip irrigation consistently promoted growth during all growth stages, especially under higher P application. (2) P application significantly increased the dry weight and P concentration in maize roots, stems, leaves, ears, and grains. Under micro-nano bubble water drip irrigation, the P concentrations in roots and grains increased by 59.28% to 92.59%. (3) Micro-nano bubble water drip irrigation significantly enhanced P uptake efficiency, partial factor productivity of P, and agronomic P use efficiency. Particularly under P1 and P2 treatments, the increases were 134.91% and 45.42%, respectively. Although the effect on apparent P recovery efficiency was relatively small, micro-nano bubble water drip irrigation still improved P utilization under moderate P levels. (4) Structural equation modeling indicated that P supply under micro-nano bubble water drip irrigation primarily regulated alkaline protease and alkaline phosphatase, enhancing soil P availability, which in turn promoted maize P accumulation and increased yield. In conclusion, this study demonstrated that the combination of micro-nano bubble water drip irrigation and appropriate P application can effectively promote maize growth and nutrient utilization, providing a theoretical basis for optimizing irrigation and fertilization strategies in maize production.

Отглеждане на соя при висока почвена влажност

The aim of this work is to study the biological and economic effect of growing soybeans at high soil moisture. The experiment is two-year and was conducted in the experimental field of AU - Plovdiv in 2009 and 2010. The variants are: 1) No irrigation, 2) Irrigation at 80% FC (field capacity), 3) Irrigation at 90% FC. When maintaining higher pre-irrigation moisture, the number of irrigation applications increases by an average of 3, and irrigation rates decrease by between 22 and 53%. The duration of the irrigation period increases by ten days. According to the results, the maintenance of high soil moisture for soybean is unjustified from a biological point of view, since the increase in the productive potential of the plants is not realized in reality. It can be considered that regardless of the irrigation method, the pre-irrigation humidity should be no higher than 80% FC for the soil layer 0-60 cm. When maintaining high soil moisture (above 90% FC), production costs increase by an average of 11%, without increasing the cost price and hardly affecting the net income, and the results for this indicator are not unidirectional.

Reinforcement Learning Algorithm for Optimising Durian Irrigation Systems: Maximising Growth and Water Efficiency

This study presents a Reinforcement Learning-based algorithm designed to optimise irrigation for Durio Zibethinus (i.e., durian) trees, aiming to maximise tree growth and reduce water usage. Traditional irrigation methods, as well as current machine learning models, often focus only on soil moisture and weather data, neglecting critical factors like actual tree growth. This study proposed a reinforcement learning irrigation (RL-Irr) algorithm incorporating tree growth stages, soil moisture, and weather conditions to determine precise irrigation needs. The algorithm was developed by calibrating the AQUACROP model using data from actual durian plantations where rain-fed irrigation (rain-fed) was practised. Daily irrigation volumes were calculated based on real-time soil moisture, weather forecasts, and weekly tree growth measurements. The reinforcement learning method was used to optimise irrigation schedules, with rewards based on soil moisture, tree growth, rainfall, and weather conditions. The algorithm was tested using AQUACROP simulations and compared against soil moisture balance irrigation (SMB-Irr) and rain-fed. The results showed that the RL-Irr reduced water use by up to 75 percent while maintaining tree growth. These findings suggest the algorithm could significantly improve water efficiency in durian farming, though real-world applications should consider potential model limitations.

Stakeholder-based management of ecosystem services in agricultural areas: Integrating the leader-follower game and a conflict resolution model

Given the substantial effects of agricultural practices on the environment, this paper introduces a novel stakeholder-based framework for assessing the ecosystem services (ESs) provided by agricultural areas. Ecosystem services include essential functions such as water supply, food production, carbon storage, soil erosion control, and habitat support. In addition to ESs, water footprint is also taken into account to evaluate the impacts of agricultural activities on water resources. Some of the mentioned ESs are assessed using the Soil and Water Assessment Tool (SWAT). Then, by extending and combining the Conflict Resolution Model with the Composition of Probabilistic Preferences (CRMCPP) method and the leader-follower game (LFG), while considering the hierarchical structure of decision-makers, the best scenario for enhancing the ESs is selected.The Zarrinehroud River Basin (ZRB) in Iran has been chosen as a case study to evaluate the performance of the proposed framework, as this basin is vital for supplying water to Lake Urmia, the largest hypersaline lake in the Middle East. In this paper, 16 Water and Environmental Resources Management (WERM) scenarios have been defined according to the Urmia Lake Restoration National Committee (ULRNC) projects. Then, the mentioned ESs have been evaluated under different WERM scenarios. Ultimately, by utilizing the CRMCPP-LFG method and taking into account the hierarchical structure of decision-makers, we can identify the optimal WERM scenario. The criteria for making this decision include various factors, such as ecosystem services and the costs involved in implementing the WERM scenarios. In the selected scenario, the average water inflow into Lake Urmia is projected to rise to 1329 million cubic meters per year, which is 6.3% more than the average inflow in the current condition. Key initiatives in this scenario include reducing cultivated areas, altering irrigation methods, changing crop patterns, and incorporating water-efficient plant species.

Integrated modeling of surface water and groundwater interactions in the Eastern Mitidja Plain, North Algeria: investigating the impact of human activities and climate change

ABSTRACT The study aims to investigate surface water (SW)–groundwater (GW) interactions in the Mitidja Plain (northern Algeria), taking into account the impacts of human activity and climate change emphasizing the alignment with Sustainable Development Goals, Clean Water and Sanitation, and Climate Action. The dynamic interactions between the El Hamiz River and the alluvial aquifer were studied using MODFLOW 6. A typical scenario analysis approach was employed, considering historical and projected climate conditions based on Coupled Model Intercomparison Project version 5 and Coupled Model Intercomparison Project phase 6 models, as well as current and projected GW abstraction rates. The findings reveal substantial changes in flow dynamics over time. In 1982, the aquifer refilled the river at a rate of 2.59 m3/s. In 2019, a new state was observed where the opposite occurred the river recharged the aquifer at a rate of 0.73 m3/s. This reduction in the flow rate can be attributed to over-pumping and declining recharge rates, and this pattern is anticipated to persist in the future. Furthermore, future forecasts indicate that GW overuse has a greater impact on GW dynamics compared to climate change. However, the adoption of saltwater desalination and enhanced irrigation methods could make a significant contribution to the sustainable development of GW resources, with an increase of up to approximately 14 m.

Assessment of Farmer’s Attitude towards Drip and Traditional Irrigation System in Junagadh District, Gujarat

Cotton (Gossypium herbaceum) is a leading natural fiber crop that is cultivated for its soft, fluffy staple fiber. Drip irrigation is a method of irrigation wherein water is carried to the plant under low pressure, through small diameter plastic pipes and delivered at the root zone drop by drop through an emitting device. The research was conducted in Junagadh district, utilizing a multistage sampling technique. A total of 160 farmers comprising 80 drip irrigation user and 80 conventional irrigation system users were surveyed. Likert’s scale with three point scale was used to analyse attitude towards the drip and traditional irrigation system by using 10 statements for each respondents. The farmers in the research area having positive attitudes toward the drip irrigationmethods as positive trend with value 66.25% was observed among drip respondents. This positive attitude reflects the behavioural intention towards the acceptance of irrigation systems. The study also revealed that 48.75% of the non-adopter farmers had the positive attitude toward the traditional irrigation methods whereas 51.25% of them had a negative and neutral attitude.

Crop Water Stress Index and Yield Relationships for Winter Wheat (Triticum aestivum) Crops Grown Under Different Drip and Flood Irrigated Treatments

ABSTRACTThe Crop Water Stress Index (CWSI) is a widely used method for quantifying crop water status and predicting yield. However, its evaluation across different irrigation methods and its stage‐specific response to crop yield is rarely evaluated. In this study, controlled field experiments were conducted on winter wheat using drip irrigation (DI) and flood irrigation (FI) during the 2021–2022 and 2022–2023 seasons in western Uttar Pradesh, India. The irrigation treatments included 50% MAD (maximum allowable depletion) (DI), 55% MAD (DI), 60% MAD (DI), 50% MAD (FI), local farmer's field replication (FI), rain‐fed, and well‐watered treatment (DI). The derived mean CWSI values for the irrigation treatments ranged from 0.03 to 0.66 in season 1 and 0.06 to 0.57 in season 2 across treatments. The seasonal mean CWSI for 50% MAD (DI) was 0.12 (season 1) and 0.11 (season 2), while 50% MAD (FI) yielded higher mean CWSI values of 0.29 (season 1) and 0.22 (season 2). The 50% MAD (DI) treatment produced the highest grain yield and water use efficiency in both seasons. A comprehensive analysis of stage‐specific CWSI values and grain yields revealed that grain yield was more sensitive to post‐heading CWSI as compared to pre‐heading CWSI values. Among the growth stages, CWSI values during the flowering stage were the most critical for predicting wheat yield. The study recommends that the CWSI values in the flowering and post‐heading stages are more relevant in predicting wheat yield accurately as compared to the pre‐heading and seasonal mean CWSI.

Water Use Efficiency in Rice Under Alternative Wetting and Drying Technique Using Energy Balance Model with UAV Information and AquaCrop in Lambayeque, Peru

In the context of global warming, rising air temperatures are increasing evapotranspiration (ETc) in all agricultural crops, including rice, a staple food worldwide. Simultaneously, the occurrence of droughts is reducing water availability, affecting traditional irrigation methods for rice cultivation (flood irrigation). The objective of this study was to determine ETc (water use) and yield performance in rice crop under different irrigation regimes: treatments with continuous flood irrigation (CF) and irrigations with alternating wetting and drying (AWD5, AWD10, and AWD20) in an experimental area in INIA–Vista Florida. Water balance, rice physiological data, and yield were measured in the field, and local weather data and thermal and multispectral images were collected with a meteorological station and a UAV (a total of 13 flights). ETc values obtained by applying the METRICTM (Mapping Evapotranspiration at High Resolution using Internalized Calibration) energy balance model ranged from 2.4 to 8.9 mm d−1 for the AWD and CF irrigation regimes. In addition, ETc was estimated by a water balance using the AquaCrop model, previously parameterized with RGB image data and field weather data, soil, irrigation water, and crops, obtaining values between 4.3 and 7.1 mm d−1 for the AWD and CF irrigation regimes. The results indicated that AWD irrigation allows for water savings of 27 to 28%, although it entails a yield reduction of from 2 to 15%, which translates into an increase in water use efficiency (WUE) of from 18 to 36%, allowing for optimizing water use and improving irrigation management.

Modified Surface Drip Irrigation and Hydraulic Barrier Impacts on Soil Moisture and Water Productivity for Tomatoes in a Greenhouse

Considerable amounts of irrigation water of vegetable crops grown in homogenous sandy soil profiles could be subjected to deep percolation water losses due to inappropriately designed surface or subsurface drip irrigation methods. This study aimed to investigate the combined influence of implementing clay soil layer in homogenous sandy soil profile of low-tech greenhouse ridges and using modified surface drip irrigation (M-DI) on soil moisture distribution and water productivity of tomatoes. In the greenhouse, a 7.5 cm thick clay soil layer was implemented 15 cm from the soil surface of each ridge as a hydraulic barrier. Three irrigation regimes (100%, 70% and 50% of ETo) were imposed with the M-DI on tomato plants and 100%ETo with surface drip irrigation (DI) as control. Regarding economic valuation, viability was preserved for the M-DI and DI methods. The outcome indicated that soil moisture spreads more horizontally than vertically on the sandy soil above the clay soil layer. The combined effect of the homogenous sandy soil profile amendment and full irrigation (100%ETo) with the M-DI irrigation method increased the tomato fruit yield by 64.5%. Furthermore, the combined influence enhanced water productivity by the M-DI to 54.7 kg/m3 compared to 32 kg/m3 by the DI. However, M-DI demonstrated dominance over DI regarding returns, yield, and profit. Economic-wise, the M-DI requires 50% less of the lateral pipelines needed by the DI in low-tech greenhouses. Adopting the M-DI with a hydraulic barrier can improve soil moisture, water productivity, yield, and returns for tomato crops in low-tech greenhouses under sandy soil conditions. Also, the M-DI with the hydraulic clay barriers was an economically viable investment compared to the DI without clay barriers for growing tomatoes in low-tech greenhouses.

Bonding and Cleaning Effects of Irrigation Protocols Using Calcium Hypochlorite on the Post-space Radicular Dentin.

This study evaluated the effect of 2.5% sodium hypochlorite (SH) or calcium hypochlorite (CH) submitted to passive ultrasonic irrigation (PUI) or conventional irrigation (CI) on the incidence of residues and the bond strength of the cementation system to post-space dentin. Distilled water (DW) and 2.5% SH followed by 17% EDTA (SH-ED) were used as negative and positive control groups, respectively. The cervical, middle, and apical thirds of the post space were evaluated. One hundred and twenty bovine incisors were endodontically treated and post-space preparation was performed. The specimens were randomly assigned to six groups, according to the solution and irrigation method: DW-CI, SH-ED-CI-SH, SH-CI, SH-PUI, CH-CI, and CH-PUI. The incidence of residues (n=10) over the dentin was evaluated by scores using SEM images. Other specimens were irrigated as previously described and the post cementation was immediately performed using a conventional dual resin cement and a two-step etch-and-rinse adhesive system. Push-out and failure modes were performed for bonding evaluation. Kruskal-Wallis and Dunn test for incidence of residues data and one-way ANOVA and Tukey tests for bond strength data were used at a significance level of 5%. The protocols that showed a lower incidence of residues were: SH-ED-CI-SH, SH-PUI, and CH-PUI for the cervical third and SHED-CI-SH for the middle third (p<0.05). In the apical third, the protocols were similar to each other (p>0.05). Bond strength values were higher after irrigation with DW-CI for all thirds (p<0.05). 2.5% sodium or calcium hypochlorite negatively impacted the adhesion interface and exhibited a greater incidence of residues over the post-space radicular dentin.

Microplastics in different nasal irrigation options.

We aimed to assess the presence of microplastics in nasal irrigation methods commonly used in the treatment of sinusitis and rhinitis, and to evaluate human exposure. A total of 150 samples were included in the study, consisting of nasal wash bottles containing nasal irrigation solution, seawater spray, syringes for nasal irrigation with isotonic solution. The amount of microplastics per millilitre in the samples and patient exposure during single use were assessed separately for each method and product. All samples were filtered using a stainless steel vacuum filter on filter paper with a pore size of 1.2μm, washed at least three times with distilled water and incubated at 45°C for 24h to prevent mould growth. Identification and counting of microplastics was performed using a Leica Flexacam C1 camera connected to an M80 stereomicroscope. The presence of microplastics was confirmed by the hot needle method and Nile red staining. An average of 6.49 ± 13.08 microplastics/product was detected in all filtered samples. The lowest microplastic count was 0 microplastics/product in syringes and the highest was 92 microplastics/product in nasal wash bottles. Significant differences in the amount of microplastics individuals were exposed to during a single use were found between nasal wash bottles and seawater brands, while no significant differences were found between syringe brands. When nasal wash kits, seawater sprays and isotonic nasal rinses were evaluated separately, significant differences were found in the number of microplastics, the microplastics/ml ratio and the number of microplastics exposed during a single use. The highest microplastic exposure was found in nasal irrigation bottles. The exposure of individuals to microplastics increases with medical support treatments, regardless of intranasal or intravenous administration. Due to the inflammation, oxidative stress and proliferation caused by microplastics, new regulations and inspections of production conditions should be implemented worldwide to reduce exposure.