Irrigation Volume Research Articles

How Different Mulch Materials Regulate Soil Moisture and Microbiological Activity?

As a result of climate change, the frequency of droughts across Europe is showing an increasing trend. The solution to this problem can be various soil cover techniques, which help to preserve soil moisture and soil biological activity, thereby increasing crop yield. In our research, we examined how different mulch materials affect the regulation of soil moisture and the microbiological activity of the soil. The experiments were set up on two sites: a sandy soil with a low soil organic matter content (Királyhalom, Serbia) and an coarse loamy soil with a higher water capacity (Thessaloniki, Greece). The treatments were set up in 4 repetitions with pepper plants (Capsicum annuum L.). Daily intensive irrigation with wool mulch, agrotextile, straw mulch and control treatments was used on the Serbian site. The irrigation was carried out every 6 days at the Greek site, where the treatments were as follows: wool mulch with plants, wool mulch without plants, plants without mulch and the control without plants. The yield was measured, and the moisture content, β-glucosidase activity and active (permanganate oxidizable) carbon content of the soils at the time of sampling were examined every 2 weeks. In the Serbian area, wool mulch showed significantly lower β-glucosidase activity compared to the other treatments. This was presumably due to the good water absorption capacity of the wool mulch and the fact that the soil could not aerate in addition to the intensive irrigation, thus the enzyme activity decreased. All mulch treatments increased the active carbon content compared to the untreated control, with the straw mulch to the greatest extent. In the extensively irrigated Greek soil, β-glucosidase was significantly higher in pepper plots covered with wool mulch compared to the control area without plants, but also higher compared to pepper plots not covered with wool mulch. The higher yield results measured on the mulched plots indicate that, in addition to water retention, biological activity also plays a major role in the development of yields. The effect of each mulching method on soil biological activity depends on the degradability of the mulch material, the frequency of irrigation, and the soil's water-holding capacity.

Evaluation of Crop Diversification on Indian Farming Practices: A Panel Regression Approach

Crop diversification is considered as a means to promote agricultural development while lowering its environmental implications. Diversified food production must substantially increase to fulfil the needs of food security and sustainability for the world’s future population. This study identified the finer details of diversification in India’s 20 agriculturally prosperous states through analyzing the regional trends in agricultural diversification. The analysis, which covered the period from 1971–1972 to 2017–2018, showed that agricultural diversification has taken place in several states of India. This study revealed that, due to the significant heterogeneity in agro-climatic and socio-economic conditions, the type of diversification varies among the regions. In these periods, cash- crop percentage in the gross-cropped area has increased from 18 percent to 37 percent, reflecting a major impact on the Shannon-Wiener diversification index. Crop diversification has been influenced by rural literacy, irrigation intensity, road infrastructure, per-capita, gross-state-domestic products, regional-rural-branch intensity, rainfall deviation, credit intensity, and India’s growing urban population, whereas cropping intensity has not affected crop diversification in India.

An agro-hydrological process-based export coefficient model for estimating monthly non-point source loads in a semiarid agricultural area

Export coefficient models (ECM) with few parameters and simple structures have been widely used to estimate nonpoint source (NPS) pollution loads. However, they are unsuitable to simulate characteristics and distributions of NPS pollution over semiarid agricultural watersheds of intensive irrigation, infrequent precipitation, and shallow groundwater. In this study, field monitoring was conducted to identify key impact factors of total nitrogen (TN) loads from NPS pollution over a typical semiarid agricultural watershed in northern China. Sources and characteristics of TN loads were examined by integrating the monitoring, a Pearson correlation analysis, an agro-hydrologic model, and a genetic algorithm into an ECM framework. This study quantitatively revealed the relationship between agro-hydrologic features and NPS nitrogen pollution in semiarid agricultural areas; it also simplified quantification of nutrient distributions in various seasons under pollution-source diversity. An accurate ECM was constructed to simulate variation of TN loads with seasons. Compared with traditional ones, the developed model reduces the simulation error of TN loads from 16.2% to 8.9% and improves R2 from 0.072 to 0.692. Simulation results show that the dominant TN nutrient source, i.e., farmland, accounts for 49% of annual TN loads. If water use efficiency increases from 40% to 50%, the largest reduction of TN loads would occur on farmland (about 14.4%), followed by grassland (12.0%), construction land (11.5%), bare land (11.0%), and woodland (8.3%). Improving water use efficiency and optimizing irrigation schemes and land use types should be preferentially recommended for NPS pollution control over semiarid agricultural regions.

Medium-Term Outcomes of Antegrade Continent Enema (ACE): Cairo University Specialized Pediatric Hospital (CUSPH) Experience

Aim of the studyTo assess the medium-term outcomes of ACE in children with fecal incontinence (FI). MethodEligible children were recruited from the colorectal clinic between December 2016 and January 2020 and were followed prospectively for 2–6 years. A series of questionnaires were used to assess QOL, patients and parent satisfaction, and to assess the outcomes of the ACE. Result24 children aged 6–12 years (mean age 8.17 ± 1.95), including 18 males (75%) and 6 females (25% were studied. Cases included anorectal malformations (45.83%)., Hirschsprung disease (25%), neural tube defects (16.66%), sacrococcygeal teratoma (4.16%), and intractable pseudoincontinence (8.33%). QOL improved from (3) [3 -3] to (16) [16-16],p < 0.05. Fecal incontinence index showed significant improvement: 20 [20-20] versus 3 [0–4],p < 0.05. Bowel symptoms demonstrated improvement in the ability to decide when to pass stools and a decrease in soiling. Stooling survey showed lower scores representing better outcome. ACE questionnaire showed that the range of irrigation volumes used by parents is wide, and that all families recommend the ACE for children with similar condition. Postoperative complications were stenosis (16.66%), stomal prolapse (12.5%), leakage (4.16%), and false passage (4.16%). Satisfaction questionnaire showed a median score of 9 (range, 5–10). ConclusionACE is an effective method to keep the child with FI clean, more socially active, and with a better QOL and FII in the medium-term. The reported complications were stenosis, false passage, and leakage. ACE mucosa prolapse is a novel complication picked up on medium-term follow up.

Sustainability Assessment of Productive Palm Tree Plantation in the Arid Regions of Urban Landscapes: A Dubai Case Study

Dubai has imported elegant plants and trees to maintain a green and attractive outdoor atmosphere. However, a substantial proportion of the imported plants are not suitable for the arid climate of United Arab Emirates (UAE) and require intensive irrigation. This poses the potential of replacing all the greenery with date palm trees that are compatible with the region&amp;rsquo;s climate and require more moderate irrigation. The availability and value of reclaimed irrigation water, the local soil quality, the cost analysis of date palm tree plantation, the productivity of palm trees, the appropriateness of types of palm trees, the nutritional value of dates, the required gardening workforce, maintenance schedule, and its positioning in relation to seasonal business activities are also explored. Dubai has the capacity to accommodate sixteen times the number palm trees it currently has.

Enhancing resource use efficiency of alfalfa with appropriate irrigation and fertilization strategy mitigate greenhouse gases emissions in the arid region of Northwest China

With the increasing global warming concerns, appropriate agronomic practices for improving crop yields while reducing greenhouse gases (GHGs) emissions are essential for sustainable agricultural production. However, little information is available if these benefits can be achieved simultaneously in arid pastoral agriculture systems with irrigation and nitrogen (N) management. We assumed that the local practiced irrigation (600 mm) and N (300 kg ha −1 ) applications for spring wheat in the arid regions of Northwest China are excessive, and optimizing irrigation-N rates would improve the resource use efficiency of alfalfa and reduce GHGs emissions. A two-year field study (2015–2016) was conducted to investigate the effects of irrigation regimes (I L , 300 mm; I M , 450 mm; and I H , 600 mm) and N application rates (F 0 , 0; F L , 150; F M , 225; and F H , 300 kg ha −1 ) on forage yield, resource use efficiency, and GHGs emissions from alfalfa fields. The GHGs emissions during alfalfa growing seasons were assessed by analyzing gas samples using the static chamber-gas chromatography method. High irrigation and N application (I H F H ) was associated with elevated GHGs emissions, global warming potential, and greenhouse gas intensity, but lower irrigation water productivity (IWP) and partial factor productivity of N (PFP N ). Reducing the irrigation and N rates decreased the GHGs emissions but differently affected alfalfa yield and resource use efficiencies. Among all the treatments, I M F L and I H F L resulted in the highest alfalfa yields, IWP, and PFP N . However, I M F L showed a good trade-off between yield benefits and environmental performance manifested by lower GHGs emissions, GWP, and GHGI. The I M F L reduced the cumulative emissions of nitrous oxide by 67.83% and 67.16%, carbon dioxide by 31.05% and 34.60%, GWP by 61.72% and 70.40%, and GHGI by 74.37% and 79.78%, while increased alfalfa yield by 49.24% and 46.45%, IWP by 99.05% and 94.97%, and PFP N by 198.44% and 192.90% compared to I H F H . Regardless of all the treatments, the alfalfa field acted as a CH 4 sink during both crop-growing seasons. Our results suggest that the application of 450 mm irrigation and 150 kg N ha −1 could be used as an appropriate management strategy for enhancing resource use efficiencies and mitigating GHGs emissions, GHGI, and GWP from alfalfa fields. The findings can provide an opportunity for greenhouse gas mitigation without alfalfa forage yield reduction following the proper irrigation and fertilization regimes in the arid region of northwest China and areas with similar agro-climatic conditions. • Intensive irrigation and fertilization increase GHGs emissions and global warming potential. • Enhancing resource use efficiency with suitable irrigation and N rates mitigate GHGs emissions. • Soil moistures and inorganic N contents are the major factors regulating GHGs emissions. • 450 mm irrigation and 150 kg N ha –1 maintain high alfalfa yields and minimize environmental impacts.

Hydraulic calculation lateral in drip irrigation

Drip irrigation systems are widely used worldwide to satisfy the water demand of agricultural crops. It is known that drip irrigation technology has a number of other advantages, such as intensive irrigation, automation, and water economical benefits. The methods which is available in hydraulics are widely used in the calculation of drip irrigation design. One of the most important issues in the drip irrigation system is the correct estimation of the discharge coming out of the drippers. As known from hydraulic calculations, it is necessary to take into account the pressure when determining the discharge coming out of the emitters. It should also be noted that discharge from emitters has a special effect on pressure losses in drip irrigation systems. The article presents the results of the research conducted in natural field conditions on the assessment of hydraulic processes in drip irrigation systems. As an object of research, the cultivated field of the “Sharifjan oglu Akhmadjon” farm in Rishton district, Fergana region was selected. The results of measurement work at 36 points of the research object are highlighted. As a result of the conducted research, recommendations for determining discharge in irrigation pipes were developed.

Matching crop row and dripline distance in subsurface drip irrigation increases yield and mitigates N2O emissions

Intensive irrigation and nitrogen (N) fertilization are often linked to low N-fertilizer efficiency, and to high emissions of the greenhouse gas nitrous oxide (N 2 O). Efficient irrigation systems (e.g. subsurface drip irrigation [SDI]) combined with N-fertigation in a no-till agroecosystem can promote N-use efficiency, thereby curbing N 2 O emissions without depressing crop yield. Yet, crop type and SDI plant settings (and management) such as dripline spacing may determine the agronomic and environmental performance of SDI. In this two-year field study on maize ( Zea mays L.) - soybean ( Glycine max [L.] Merr.) rotation with conservation agriculture management (no-till and cover crops), we investigated the effects of three different irrigation/fertilization systems (SDI with a narrow dripline spacing (70 cm) + fertigation with ammonium sulphate, SDI with a large dripline spacing (140 cm) + fertigation with ammonium sulphate, and sprinkler irrigation [SPR] + granular urea application) on yield, N-fertilizer efficiency, and N 2 O emissions in a fine-textured soil. We hypothesized that SDI systems (especially with narrow dripline distance) would increase yield and mitigate N 2 O compared with SPR, and particularly for maize due to its higher water and nutrient demand. We found that SDI increased maize yield (+31%) and N-fertilizer efficiency (+43–71%). These positive results were only observed during the drier year in which irrigation supplied ca. 80% of maize water requirements. The narrower dripline spacing mitigated N 2 O emissions compared with sprinkler irrigation (by 44%) and with the wider spacing (by 36%), due to a more homogeneous distribution of N in soil, and to a lower soil moisture content. Soybean yield and N-use efficiency were not affected by the irrigation systems. We also found that SPR enhanced cover crop residue decomposition, thus promoting the release of C and N into the soil and increasing N 2 O emissions. Overall, our study provides important insights on key management decisions that define the sustainability of novel irrigation systems; in particular SDI with a 70 cm dripline distance should be promoted for maize to increase productivity and decrease N 2 O emissions in fine-textured soils. • Benefits of SDI increases with high water and N demanding crops. • SDI increases maize yield and N-fertilizer efficiency during dry years. • Narrow dripline distance (0.70 m) mitigates N 2 O emissions. • N release from litter decomposition may play a major role in N 2 O emissions.

An enhanced version of the D-Risk decision support webtool for multi-scale management of water abstraction and drought risks in irrigated agriculture

Due to it having the lowest priority for water allocation during drought events and the consequent agronomic and economic impacts of abstraction restrictions, UK irrigated agriculture has been identified as a key business sector ‘at risk’. An enhanced version of the D-Risk webtool has been developed to help agricultural stakeholders and catchment water managers to evaluate the joint multi-scale risks of abstraction restrictions (voluntary and mandatory) and having insufficient irrigation volumes during drought events. The webtool uses annual maximum potential soil moisture deficit as the agroclimate index to calculate monthly and annual volumetric irrigation demand for the selected crop mix, soil available water capacity and location. Simulated river flows are used to identify days not under abstraction restrictions. Annual probability distributions of irrigation deficit and licence utilisation (headroom) are derived from a monthly time-step water balance model that calculates whether the farm irrigation demand in each month can be met, taking account of river flow-based abstraction restrictions, daily and annual volumetric licensed abstraction limits, the licenced abstraction period(s) and any on-farm reservoir storage. The enhanced D-Risk tool provides a more holistic understanding of drought risk on irrigated agriculture from individual farm to catchment scales and supports improved collaborative decision-making regarding future water sharing, water trading and on-farm reservoir investment to reduce business vulnerability to drought and regulatory change.

Effects of postharvest deficit irrigation on sweet cherry (Prunus avium) in five Okanagan Valley, Canada, orchards: I. Tree water status, photosynthesis, and growth

The timing and availability of water supply are changing in the Okanagan Valley, and the availability of irrigation water in the late summers is a growing concern. Postharvest deficit irrigation (PDI) is a strategy that can be used to reduce water demands in sweet cherry orchards; previous studies in this region have reported no change in plant physiology or tree growth with irrigation volume reductions of up to 25%, postharvest. However, the effects of more severe postharvest reductions in irrigation volume remain unknown. We compared the effects of full irrigation (100% of conventional grower practice through the growing season) with 27%–33% reductions in irrigation postharvest (∼70% of conventional grower practice) and 47%–52% reductions in irrigation postharvest (∼50% of conventional grower practice) over a 3-year period (2019–2021) in five commercial sweet cherry orchards that ranged in elevation and latitude across the Okanagan Valley, BC, Canada. In the growing season following treatment application, PDI had no effect on stem water potential or photosynthesis in any year and at any site; there were also no effects of PDI treatment on tree growth. Findings from this study suggest that postharvest stem water potentials from −0.5 to −1.3 MPa, and one-time stem water potentials as low as −2.0 MPa, have no lasting effects on future plant water status, rates of photosynthesis, or plant growth. PDI shows potential as an effective water-saving measure in sweet cherry orchards in the Okanagan Valley.

Nitrogen and phosphorus budget in an intensive irrigation area and effects on littoral water and groundwater (Yaqui Valley, Northwestern Mexico).

The Yaqui River Irrigation District is a region in Mexico with intensive agricultural production; thus, large quantities of fertilizers are used, and excess fertilizer can affect the quality of water bodies. The aim of this work was to estimate the water budget and nitrogen (N) and phosphorous (P) mass budgets to evaluate possible contamination of a littoral water body (Tóbari Bay) and leachates into an aquifer (Yaqui Valley aquifer). Wheat and corn crops were studied, climate information was compiled, and soil and water samples were collected for analysis. The water budget showed excess irrigation occurred due to the need for soil washing to prevent salinization. A total of 24% of all irrigation water was used for crops, 60% was discharged into the bay through runoff of the drainage system, and 16% corresponded to effective infiltration (aquifer recharge). The N budget showed that of the 100% N input, the highest percentage was used by plants (63%), and only minimal loss occurred through runoff (11%) and leachate into the aquifer (7%). The remaining N stayed in the soil (18%) or was volatilized (1%). These results indicate that the drainage system prevented large amounts of N from entering the aquifer; thus, the N concentrations in the groundwater did not exceed the regulated maximum limit for drinking water (10mgN-NO3/L). In terms of the water pollution level in the bay, the presence of NO3- was minimal (concentrations below the quasintifiable limit). Of the 100% of P that was applied, 55% was used by the plants, and 40% remained in the soil; therefore, the P that was transported by runoff or was leached was minimal (3 and 2%, respectively). However, this minimal amount of P ranged from 0.1 to 0.2mg/L in the bay, and these values exceeded the suggested values for the protection of aquatic life (0.01mg/L). The administrators of the irrigation district must pay special attention to phosphate fertilizer management and implement irrigation techniques that increase water use efficiency.

Water regime enhances the effects of flue gas desulfurization gypsum on the reclamation of highly saline‐sodic soil

AbstractFlue gas desulfurization (FGD) gypsum‐based reclamation of saline‐sodic soil has been widely used in the Songnen Plain of China, but its reclamation effect depends on the water regime. A pot experiment was conducted to identify the optimal water regimes for reclaiming a highly saline‐sodic soil [pH, electrical conductivity (EC) and exchangeable sodium percentage (ESP) were 10.4, 5.5 dS m‒1 and 68.1%, respectively] by using FGD gypsum. Three water regimes with drainage times [irrigation amounts of 3‐, 5‐, and 7‐times the soil pore volume (PV)] were selected and FGD gypsum was added to a portion of the regimes before the final drainage operation. Then the saline‐sodic parameters of drainage and soil were measured and analyzed. Na+, Cl−, HCO3−, and SO42− were the main ions in the drainage of all the treatments. With the increase in drainage times, the water regime without FGD gypsum notably decreased soil EC by 17.8%–52.0%. In contrast to the FGD gypsum treatment, the water regime failed to decrease the soil ESP. FGD gypsum application with three drainage times had optimal reclamation with reductions in soil pH and ESP of 0.5–2.3 units and 5.1%–20.1%, respectivley. But the associated water consumption was more than 40% higher than that of one‐ or two‐drainage operations. In terms of water reduction (irrigation volume was 5 times PV), sodicity reduction and salt removal (soil pH, ESP, and EC were reduced by 1.7 units, 12.3%, and 1.12 dS m−1), FGD gypsum application with two‐time drainage could be a more suitable measure to reclaim highly saline‐sodic soil.

A Revised Equation of Water Application Efficiency in a Center Pivot System Used in Crop Rotation in No Tillage

Correctly quantifying total losses of irrigation in a center pivot system is important for improving application management and efficiency (Ea). The equations usually used to estimate Ea in sprinkler irrigation systems do not consider certain aspects, such as height of sprinklers relative to crop height, leaf interception (LI) of tall-growing crops or partial residue retention (PRR). The aim of this study was to incorporate these components into a new Ea equation adapted to the center pivot system. The trials were conducted in corn grown under no tillage in Córdoba, Argentina. To determine the distribution uniformity (DUpa), 96 catch cans were arranged at a spacing of 3 m, and the sprinklers with similar discharge flow from a center pivot of five towers (27.8 ha) were grouped together. Four irrigation depths (40, 24, 12 and 6 mm) were evaluated at different phenological stages, as well as the control condition without crop. Twenty-eight measurements were taken, and DUpa was statistically compared with respect to the different depths applied and phenological stages as well as the impact on yield. For the 11 grouped segments, with irrigation intensity between 5.7 and 77.4 mm h−1, DUpa for the control condition ranged from very good to excellent (85 to 90%) but decreased significantly with crop growth. Neither the different intensities nor the irrigation depths influenced DUpa up to V10, when it decreased significantly for the 6 mm depth. The spacing between sprinklers had an effect on DUpa and crop yield, decreasing from 18 to 14 ton ha−1 with the largest spacing (5 m). PRR and LI were statistically adjusted, and a revised equation of application efficiency was obtained.

Evaluation of citrus grove floor management strategies for water use efficiency and conservation

Perennial crops require water year-round, straining water resources, particularly in arid and semi-arid regions throught the world. Of those regions, the Lower Rio Grande Valley of Texas, USA, depends on flood irrigation to meet water demands of crops. Approximately 60–70% of citrus producers use flood irrigation to irrigate their groves, which is less efficient than other irrigation methods such as micro-jet or drip irrigation. Flood irrigation is to reduce cost, equipment, and energy required, and no land needs to be taken out of production to be used for holding ponds. Therefore, conservation practices that are adapted for flood irrigation are necessary in these areas where infrastructure is less conducive to other practices. Water use efficiency and potential water savings in different grove-floor management strategies, citrus tree growth, soil moisture, and irrigation volume were measured over the course of 3 years (from establishment to first harvest) in four different grove floor management strategies. These strategies, flat-bed no plastic mesh groundcover (traditional), flat-bed with plastic mesh groundcover, raised bed no groundcover, and raised bed with groundcover showed varying impacts on young citrus tree growth, soil moisture, and water savings over this study period. By the end of the study, 2.2% water savings (44,403 L over 4 years) were found in the flat bed with groundcover treatment compared to traditional grove floor management. This treatment also resulted in higher water use efficiency and greater initial growth of young citrus. Overall, the use of ground cover showed much potential for conserving water compared to traditional, uncovered flat bed management methods. These grove floor management practices can improve tree growth and establishment in young citrus trees in addition to improving water use efficiency. However, it is yet to see how these benefits will translate to more mature trees.

Shared centre pivot. An experience of smallholder irrigation in Midwest Brazil

Irrigation enables crop intensification and improves the smallholder’s household livelihood. Centre pivot irrigation, a system predominantly used in medium to large individual farms, has recently been promoted for smallholder collective irrigation in developing countries. The objective of this research was to assess the irrigation performance and evolution of shared centre pivot systems at the Itamarati Rural Settlement in the Midwest of Brazil, where around 1000 smallholders were organized in small groups between 2001 and 2004, to farm 85 centre pivots collectively. Quantitative and qualitative data were collected in a mixed-approach, and used to characterize the evolution and sustainability of the centre pivots shared. We collected information from published and unpublished reports, and we conducted our own surveys, interviewing twenty-five farm groups and forming focus groups in a 3-year phased process. Irrigation intensity (the ratio of irrigated area over the area equipped for irrigation) declined sharply from 0.75 in 2004/2005–0.12 in 2020. The immediate pressures triggering the abandonment process were: the farmers’ insufficient technical capability, low productivity of the irrigated crops, and high operational and maintenance costs. At the root of these drivers was the incapacity to exert the collective action required by the highly centralized shared centre pivot system. The progressive giving up of collective management and the concentration of land in larger farms seems to be inexorable. The Itamarati experience was a paradigm of a top-down project whose lessons are important for policymakers. We concluded that centralized collective systems are unsustainable unless the community that adopts them has a high sense of union and a capacity for collective action.

Experimental Investigations on Influence of Fracture Networks on Overland Flow and Water Infiltration in Soil

Soil preferential flow is an essential process that affects the movement and relocation of soil water and solutes. This study was conducted on cropland in an arid and semi-arid area in Zhongning County, Ningxia. According to the different cracks, rain intensity, rainfall duration, and slope, there were three groups, and 17 dye tracer experiments were conducted in the field. We quantified the characteristics of soil preferential flow by investigating and analyzing the infiltration depth, dyeing area, saturation, runoff coefficient, and rainfall infiltration coefficient using the dye tracer method. The results showed that increasing the rainfall or irrigation intensity could promote the activation of the fracture channel as the preferential flow channel, which is advantageous to the preferential flow formation. The fractures dominated the formation of the preferential flow. The fractures slowed the formation of runoff, reduced the velocity of slope flow, reduced the flow of the slope, and increased the amount of soil water infiltration. These results have theoretical and practical significance for understanding soil water transportation, especially for agricultural irrigation management and improving cropland water use efficiency in arid and semi-arid areas.

Effects of Drip Irrigation Volumes on Plant Growth and Yield of Tomato Grown in Perlite

Effects of Drip Irrigation Volumes on Plant Growth and Yield of Tomato Grown in Perlite

Lavage Volume of Arthrocentesis in the Management of Temporomandibular Disorders: A Systematic Review and Meta-Analysis.

The aim of this study was to investigate the most effective lavage volume of arthrocentesis in the management of temporomandibular disorders. A comprehensive electronic search, based on the PRISMA guidelines, was performed, which included a computer search with specific keywords, a reference list search and a manual search. The inclusion criteria were the following: a randomized controlled trial, at least 20 subjects who underwent arthrocentesis, mention of the irrigation materials used for the arthrocentesis, mention of the irrigation volumes used for the arthrocentesis, MMO and pain measured as VAS or NRS, were reported as outcome figures, mention of a specific diagnosis or signs and symptoms, and inclusion of the data on the MMO or VAS/NRS at 6-month follow-up. Sixteen publications were enrolled in the meta-analysis, comparing arthrocentesis with a lavage volume &lt;150 mL and arthrocentesis with a lavage volume ≥150 mL, in the efficacy of the improvement in the mouth opening and pain reduction. The results revealed the group with a lavage volume &lt;150 mL had a greater improvement in the mouth opening and pain reduction. However, results are to be interpreted with caution, due to the paucity of the randomized controlled literature and other confounding factors. Further high-quality studies are required to provide a better conclusion to the treatment outcomes of the different lavage volumes.

Distribution of legacy and novel per- and polyfluoroalkyl substances in surface and groundwater affected by irrigation in an arid region

Frequent exchange of surface water and groundwater occurs in arid/semi-arid areas due to high evaporation and intensive irrigation activities, affecting the migration and transformation of per- and polyfluoroalkyl substances (PFASs) and threatening drinking water safety. This study analyzed legacy PFASs and potential precursors in surface water, groundwater, soil, and aquifer solid samples collected from a typical arid area, the Hetao Irrigation District of Northern China, to explore PFASs distribution and transformation between surface and ground. Total PFASs (ΣPFASs) in surface water was 29–232 ng/L, higher than 2–77 ng/L in groundwater. ΣPFASs in soil were 0.29–0.59 ng/g, higher than 0.09–0.27 in the aquifer solids. Regarding horizontal distribution, the concentration of PFASs in groundwater increased in downtowns and the areas recharged with lake water. In terms of vertical distribution, ΣPFASs decreased with the increase of depth, and more PFASs adsorbed on clay particles in the aquifer. The total oxidable precursor analysis showed that 8:2 FT and 4:2 FT were the dominant precursors of PFASs, resulting in an increment of 0.1–4 ng/L PFASs. Hydrogen and oxygen stable isotope compositions suggest similar sources between surface water and groundwater in the study area, while principal component analysis and Bayesian inference also indicate that surface water is an important source of groundwater PFASs. The annual infiltration PFASs to groundwater from Ulansuhai was estimated by the water balance approach to be 9.39 kg. Results highlight the influence of agricultural irrigation activities and lake infiltration on groundwater PFASs in the arid region.

Effects of global climate change on the hydrological cycle and crop growth under heavily irrigated management – A comparison between CMIP5 and CMIP6

Quantifying the impact of global climate change on the water cycle and crop production is essential for water resource management and agricultural production planning. This study compared multiple GCM (General Circulation Model) projections of CMIP5 (Coupled Model Intercomparison Project 5) and CMIP6 and further used the selected GCMs to quantify the impact of future climate change on hydrology and crop production under intensive irrigation management in the North China Plain using an improved SWAT model (SWAT-MAD). Taylor’s skill score was used firstly to screen out six groups of GCMs with better simulation performance from 10 pairs of homologous GCMs of CMIP5 and CMIP6. The selected GCMs of CMIP5 and CMIP6 were further used to drive SWAT-MAD for a robust evaluation of climate change impacts. Results showed that during winter wheat growing season, average actual evapotranspiration (ETa) increased by 3%, 3%, 4%, and 5%, respectively, under 2041–2070 RCP4.5, 2041–2070 SSP2-4.5, 2041–2100 RCP4.5, and 2071–2100 SSP2-4.5 scenarios, compared to the historical period (1971–2000). During summer maize growing season, those changes in ETa were 4%, 2%, −0.2%, and −3%. Predicted future precipitation, air temperatures, and surface runoff could increase, while irrigation could decrease as precipitation increased. The dynamic patterns of leaf area index of winter wheat and summer maize indicated that there is a tendency for early emergence and maturity of both crops in the future, and the daily total biomass elevated with a corresponding increase in final yields. The highest increases in yields of winter wheat and summer maize were 18.9% and 16.7%. The findings not only contribute to enhancing the confidence of future projections using CMIP6 but also facilitate our understanding of the relative uncertainty of GCMs. This study provides technical and data support for pre-selections of GCMs and decision making in best management practices for groundwater conservation and agricultural production.