Pulsed Irrigation Research Articles

Accumulation and exportation of macronutrients by peanut crops under pulse irrigation with brackish water

Accumulation and exportation of macronutrients by peanut crops under pulse irrigation with brackish water

Weather-based Scheduling and Pulse Drip Irrigation Increase Growth and Production of Northern Highbush Blueberry

Northern highbush blueberry (Vaccinium corymbosum L.) often requires frequent irrigation for commercial production, but irrigation is becoming increasingly challenging for many growers because of warmer and drier weather conditions, increased water regulations, and other water-use limitations. The purpose of this study was to develop improved methods of irrigation to prepare the industry more effectively against future water uncertainties. Treatments were applied for 2 years (2021 and 2022) and included a combination of weather-based or fixed irrigation schedules using continuous or pulse irrigation in a commercial field of ‘Draper’ blueberry in eastern Washington, USA. The soil at the site was a silt loam, and irrigation was applied using two laterals of drip tubing per row. Plants on a fixed schedule were irrigated for 12 to 13 hours per application (set by the grower), whereas those on a weather-based schedule were irrigated according to daily estimates of crop evapotranspiration (downloaded from an automated weather station). In both cases, irrigation was applied every 2 to 4 days as a single, continuous application or in 30- to 50-minute pulses every 2 hours (up to nine times per day) with the same amount of water as the continuous treatment. During the first year of the study, weather-based scheduling maintained greater stem water potentials in the plants and, on average, increased yield by 3.4 t⋅ha–1, berry weight by 0.14 g/berry, berry diameter by 0.4 mm, and fruit bud set by 4.3% when compared with fixed scheduling. Likewise, pulse irrigation maintained greater stem water potentials and, on average, increased berry weight and diameter by 0.10 g and 0.4 mm, respectively, fruit bud set by 3.3%, and canopy cover by 2.4% relative to continuous irrigation. Yield and canopy cover were unaffected by any treatment in the second year, which was likely a result of uncharacteristically cool, wet weather in the spring. However, weather-based scheduling continued to maintain greater stem water potentials and, when combined with pulse irrigation, increased berry weight and diameter by 3.7 g and 1.0 mm, respectively, relative to continuous irrigation on a fixed schedule. Pulse drip irrigation also increased fruit bud set by 5.1% during the second year. These results demonstrate the potential benefits of using weather-based scheduling and pulse drip in northern highbush blueberry, especially when the plants are grown on light-textured soils in hot, dry climates.

Feasibility of Using Pulse Drip Irrigation for Increasing Growth, Yield, and Water Productivity of Red Raspberry

Pulse irrigation, the practice of applying water in small doses over time, is known to reduce deep percolation and runoff and, relative to irrigating in single continuous applications, can increase plant growth and production by supplying water and nutrients at an optimal rate. The objective of the present study was to determine whether pulse irrigation was beneficial in red raspberry (Rubus idaeus L. ‘Wakefield’). Treatments included continuous or pulse drip irrigation and were evaluated for three growing seasons (2018–20) in a commercial field with silt loam soil. Continuous irrigation was applied up to 4 hours/day, whereas pulse irrigation was programmed to run for 30 minutes every 2 hours, up to eight times/day, using the same amount of water as the continuous treatment. Pulsing improved soil water availability relative to continuous irrigation and, by the second and third year, increased fruit production by 1210 to 1230 kg·ha−1, which, based on recent market prices, was equivalent to $2420 to $2460/ha per year. Much of this yield increase occurred during the latter 3 to 4 weeks of the harvest season and was primarily due to larger fruit size during the second year and more berries per plant during the third year. In 1 or both years, pulse irrigation also produced more canopy cover, larger cane diameters, and higher concentrations of Mg and S in the leaves than continuous irrigation, but it reduced K and B in the soil and had variable effects on sugar-to-acid ratio in the berries. On the basis of these results, pulsing appears to be an effective means of irrigating raspberry plants in sandy or silty loam soils, but more research is needed to determine whether it is useful technique in heavier soil types.

Statistical process control in pulsed drip irrigation systems

Pulse drip application is a management option to prevent clogging and improve water-use efficiency. The measurement of distribution uniformity is opportune for pulse irrigation projects to ensure efficiency since the shorter the pulse time, the more negative influence the transition periods have. The objective of the present work was to monitor the quality of a drip irrigation system with different emitter models and different pulse times. The experiment was conducted under laboratory bench conditions, and 25 tests were performed for each pulse application (2, 3, 6 and 12 minutes) and emitter model (non-compensated and auto-compensated). Uniformity was determined using Christiansen's uniformity coefficient (CUC) and distribution uniformity coefficient (DUC) and monitored by Shewhart control charts and exponentially weighted moving average (EWMA). The decrease in pulse time caused a decrease in flow rate and uniformity only in drip irrigation systems with non auto-compensated emitters. However, this decrease is subtle, to the point that uniformity presented an excellent performance for all pulses tested. The use of the Shewhart and EWMA control charts were effective in monitoring the uniformity of the pulsed drip irrigation system. The Shewhart control chart was more robust in identifying isolated non-compensated uniformities, while the EWMA control chart was more sensitive in identifying unstable propensity. In the treatments with the non-compensated emitter, the statistical process control was able to identify that shorter pulse times resulted in greater application instability. As for the auto-compensated emitters, the statistical process control highlighted the concern with application uniformity after maintenance interference.
 Keywords: anti-drain emitter, high-frequency irrigation, irrigation interval, statistical quality control.

The quality of endozoochorous depositions: Effect of dung on seed germination and seedling growth of Neltuma flexuosa (DC.) C.E. Hughes & G.P. Lewis

The qualitative component of the effectiveness of seed dispersal by endozoochory encompasses seed deposition. Neltuma flexuosa, a keystone tree of the Monte biome, is dispersed by several animals and in this paper we aimed to study the qualitative aspect of its dispersal. We studied the effect of the dung of Bos taurus (cow), Equus ferus caballus (horse) and Dolichotis patagonum (mara) on seed germination and growth of N. flexuosa seedlings. We conducted greenhouse experiments using dung or field soil as substrate, under two water regimes: pot capacity and pulsed irrigation; testing manually scarified seeds collected from trees. We observed that the effect of dung on the two key processes of plant regeneration was different and depended on the animal species: it either reduced or did not affect maximum germination, and promoted or did not affect seedling growth, compared to the soil. Horse and mara manure reduced germination, while manure from both domestic animals promoted seedling growth. The water storage capacity, drying rate and nutrient level of the substrates did not directly explain the results obtained. Overall, cow dung appeared as the best microsite for early regeneration of N. flexuosa, while mara manure was the most restrictive for this process.

Saline irrigation for reducing the recurrence of common bile duct stones after lithotripsy: a randomized controlled trial.

Mechanical lithotripsy produces stone fragments that are not easily detected by cholangiography and is a potential cause of recurrence of common bile duct stones (CBDS). This study aims to clarify whether 100ml saline irrigation after mechanical lithotripsy reduces the recurrent rate of CBDS. In this randomized controlled trial performed at the Surgical Endoscopy Center, the First Hospital of Lanzhou University between May 10, 2019, and Dec 31, 2020, patients undergoing endoscopic mechanical lithotripsy were randomly assigned to receive saline irrigation (study group) or no irrigation (control group). The saline irrigation was given 100ml saline pulse irrigation after cholangiography showed no residual stones. Patients were followed up for at least 24 months after endoscopic stone removal to assess the recurrence of CBDS. This study was registered with ClinicalTrials.gov (NCT03937037). During the median follow-up period of 35.6 months (interquartile range, 26.0-40.7), 43 of the 180 patients had stone recurrence (24%). The frequency of recurrence of CBD stones was 12.22% in the saline irrigation group and 35.56% in the control group, with a difference of 23.33% between the two groups (95% confidence interval [CI], 11.35%-35.32%, p<0.001). Multivariable Cox proportional hazards analyses showed that constipation (hazard risk [HR] 2.42; 95% CI, 1.22-4.80, p=0.012), periampullary diverticulum (PAD) (HR 3.06; 95% CI, 1.62-5.79, p<0.001), and total to direct bilirubin ratio (HR 1.48; 95% CI, 1.21-1.81, p<0.001) were independent risk factors for the recurrence of CBDS. Saline irrigation was the only preventive factor for the recurrence of CBDS (HR 0.22; 95% CI, 0.11-0.44, p<0.001). For patients with CBDS requiring mechanical lithotripsy, 100ml saline irrigation effectively reduces the recurrent rate of CBDS after endoscopic stone removal. This work was supported by National Natural Science Foundation of China (32160255); Natural Science Foundation of Gansu Province (22JR5RA898, 20JR10RA676); Science and Technology Planning Project of Chengguan District in Lanzhou (2020JSCX0043).

DETERMINATION OF THE PARAMETERS OF SUBSURFACE DRIP IRRIGATION SYSTEMS ON THE BASE OF MOISTURE TRANSPORT MODELING

The paper considers the problem of determining the depth of drip pipelines installation and the distance between the pipelines within the design of subsurface drip irrigation systems along with the assessment of pulse irrigation regime efficiency. The corresponding optimization problem has an objective function that assesses costs of creating and operating the system and is solved by a genetic algorithm. For each set of system parameters' values the scheduling of irrigation during the growing season is modeled according to the specified pre-irrigation threshold. The simulation is based on the two-dimensional Richards equation approximated by a finite-difference scheme. The characteristics of crop development are determined according to the model based on the change of development stages with the accumulation of a given amount of active temperatures. To take into account the variability of weather conditions modeling is performed for a series of randomly generated weather scenarios.

PRODUÇÃO E CONSUMO HÍDRICO DA BERINJELA SOB ESTRESSE SALINO IRRIGADA POR GOTEJAMENTO CONTÍNUO E PULSOS

ABSTRACT Eggplant is a vegetable considered as moderately sensitive to salinity, and its production is affected by water deficit in the soil, mainly in the reproductive phase of the crop. The objective of this study was to evaluate the use of irrigation with brackish water using continuous drip and pulse in production, water consumption, water use efficiency, and soil salinization. The experimental design was in randomized blocks, in a 4 × 4 factorial scheme, with five replicates, totaling 80 plots. The treatments consisted of four forms of water application, continuous drip, and pulse throughout the cycle; continuous drip in the vegetative phase and pulse in the reproductive phase, and pulse in the vegetative phase and drip in the reproductive phase and four levels of irrigation water salinity - ECw (0.3; 1.5; 3.0; 4.5 dS m−1). The inversion of irrigation treatments occurred 65 days after transplanting. Increase in water salinity from 0.3 to 4.5 dS m−1, the total production (-11.96%), fruit length (-5.05%), and water use efficiency (-7.01%) reduced while there was no significant effect for the forms of water application and interaction between the studied factors. Pulse irrigation provided greater water savings and resulted in higher electrical conductivity in the soil saturation extract. The efficiency of water use did not show statistical difference when continuous drip or pulse irrigation was used throughout the cycle.

Salvage of Infected Penile Prosthesis using Novel High-Pressure Pulse Irrigation System Adapted to Urological Use in Conjunction with a new Antimicrobial Solution

ABSTRACT Introduction Infection of a penile implant is a catastrophic event necessitating removal of the infected device. Removal of an infected implant is associated with significant morbidity, including penile fibrosis with associated shortening. Delayed reimplantation is associated with difficulty or maybe technically impossible. Mulcahy salvage protocol with modifications is the preferred approach when possible. Adequate irrigation is a challenge given the ‘deep-in-a-hole’ surgical anatomy where the implants are placed. In addition, there is no agreed-upon irrigant that is ideal for irrigation infected wounds. Objective We describe adaptation and modification of orthopedic high-pressure irrigation system for use in the salvage of penile prosthesis. In addition, we describe novel use in urology of a hypochlorous washing solution capable of removing microorganisms, disrupting biofilm, while being non-cytotoxic and skin-neutral. Methods Stryker Interpulse Pulsed Lavage System generating 15 pounds per square inch (PSI) of pressure was adapted for urological use in deep cavities using 16F red rubber Bard urethral catheter. Infected implant in a high-risk multiple comorbidities vasculopath was successfully salvaged without complications. Results Successful salvage of an infected penile prosthesis with a novel adaptation of existing high-pressure irrigation system. Demonstrated safely of use of antibiotic solution for penile irrigation. Conclusions In-vivo studies show significantly greater effectiveness of high-pressure pulsed salvage irrigation compared to bulb syringe irrigation. We present a practical, accessible, and effective modification of an existing high-pressure irrigation syringe for use in deep cavities, proximal and distal penile shaft. In addition, we report safe use of a new antimicrobial irrigant, hypochloric acid, for salvage of infected penile prosthesis. Disclosure No

Impact of impulse irrigation in different phases of the growing season on rice yield in the Krasnodar Territory

The article presents a study of water consumption of rice crops during periodic irrigation in various interphase periods of the growing season. The experiments were carried out on a plot of 21.2 hectares in the rice-growing enterprise of the RBF “Krasnoarmeysky”. The object of the study is an intensive variety of Rapan rice of Russian selection. The subject of the study is the water regime during the growing season of rice. It was found that the transition to intermittent irrigation during the growing season of rice “germination-tillering”, “loading-flowering” and “maturation” allowed to reduce the irrigation rate by 11.4, 5.1, 1.5%, respectively, compared with traditional methods of rice irrigation. The results of harvesting rice grains showed that the average yield according to the experiment was 75.7 c/ha, which is more than in the control by 1.2 c/ha. Additional profit from increasing the yield on the experimental variants ranged from 1,440 rubles/ha to 2,880 rubles/ha, net profit - from 480 rubles/ha to 960 rubles/ha. The total economic effect of the introduction of the pulse irrigation mode into production in various interphase periods of rice cultivation ranged from 549.83 rubles/ha to 1490.71 rubles/ha.

Flood Pulse Irrigation of Meadows Shapes Soil Chemical and Microbial Parameters More Than Mineral Fertilization

While mineral fertilization increases agricultural yields, it also bears the risk of contaminating non-target ecosystems and negatively affecting soil chemical parameters and microbial communities. This calls for alternative and more sustainable agricultural practices that reduce the use of fertilizers. Flood pulse irrigation could be an alternative to mineral fertilization of hay meadows, since it increases the yield with little or no application of fertilizer. However, the positive and negative implications of flood pulse irrigation on soil chemical parameters and particularly soil microbial communities are still largely unknown. In this study, we assessed shifts in soil microbial communities (SMC) as a response to changes in soil chemical parameters after flood pulse irrigation and/or fertilization of meadows. We determined soil chemical (Corg, Ntot, water extractable N, P, K, pH) and microbial (phospholipid-derived fatty acids, PLFA) parameters of 12 meadows in a 2 × 2 factorial design, comprising flood pulse irrigation and fertilization. Corg, Ntot, and water content as well as microbial biomass were higher in flood-irrigated than in non-flooded soils. Soil microbial biomass positively correlated with Corg, Ntot, and water extractable N. Gram-negative bacteria significantly increased, whereas the fungi/bacteria ratio significantly decreased in flood-irrigated soils compared to non-flooded soils. Arbuscular mycorrhizal fungi were positively correlated with soil pH. Flood pulse irrigation seemed to promote the build-up of a larger soil carbon and nitrogen pool as well as higher water content and microbial biomass. By this, it potentially mitigated negative mineral fertilization effects such as changed soil pH and reduced carbon use efficiency. We conclude that flood pulse irrigation may represent a sustainable alternative to mineral fertilization.

Pearls: Removing Modular Metal-on-Metal Liners using a Battery-powered Handheld Impaction System.

The number of dislocations following THA is increasing in tandem with the increased number of primary and revision THAs being performed [2, 4]. Dual mobility (DM) articulations can address this complication by allowing the use of larger diameter femoral heads [5], which may contribute to a reduced risk of dislocation associated with DM components. Perhaps for these reasons, the use of DM implants in both primary and revision THA is increasing as well [1, 3, 6-8]. Most DM implants used in the United States employ a modular cobalt chrome liner that engages the acetabular shell with a mated Morse taper. In order to perform acetabular revision on one of these modular components, the modular liner must first be dissociated from the acetabular component. Many manufacturers provide instruments or technique suggestions, but despite these, dissociating a modular DM liner from its shell can be very difficult to do. Design-specific challenges, mechanical and chemical degeneration resulting in cold welding, and corrosion causing abnormal mating of the taper interface can make these liners resistant to removal. We propose a liner removal technique that makes it easier. Techniques to loosen the taper engagement of modular cobalt chrome bearings typically involve introducing mechanical vibration to the rim or face of the acetabular component to disengage the taper using tamps or extractor “plates” [9]. This can be challenging because the force and frequency of vibration required to disengage the liner may be inconsistent and unpredictable. We found that a battery-powered, handheld impaction system (Fig. 1) provides vibration with consistent and sufficient force, frequency, and direction to loosen the modular taper junction of modular DM liners or modular metal liners without damaging the existing well-fixed acetabular shell behind the liner. The battery-powered, handheld impaction system is a standard device that is made by any of the companies that offer drill/reamer power kits.Fig. 1: The battery-powered, handheld impaction system is shown. The system shown here is provided free of charge with the DePuy primary hip system. This particular system offers several modular attachments that can be used for THA. We utilized the bullet tip attachment for this technique.To use this system, we perform a revision approach to the hip of the surgeon’s choosing, and following removal or retraction of the femoral component, we obtain adequate exposure of the acetabular component. We then position the handheld system with the tip of the adaptor on the exposed rim of the acetabular component (Fig. 2). This system typically uses an adapter to attach to the acetabular component and femoral broaches; however, a bullet tip adapter that does not require component attachment is also available. In the example depicted here, we demonstrate the bullet tip stem insertion adaptor provided by the manufacturer. After several (three to five) consistent strikes to the rim of the acetabular component, the liner usually is unseated from the acetabular shell behind it, and its displacement is both visible (Fig. 3) and palpable to the surgeon.Fig. 2: The bullet tip for the impaction system is positioned on the rim of the well-fixed acetabular component after full exposure.Fig. 3: In some cases, the cobalt chrome liner can be visualized to disengage from the acetabular component. In this view, the liner is no longer sitting flush with the rim of the component, indicating disengagement.In modular DM design in this demonstration, the liner frequently seats flush with the rim of the component, making it difficult to grasp the liner for removal from the shell even after it is unseated. Sometimes, though, visual disengagement is not clearly observed; however, in our experience, three to five taps is enough to disengage it. Therefore, in our technique, we would either use a suction device provided by the manufacturer (Fig. 4) or the suction provided by the pulse irrigation system to grasp the liner and remove it from the component (Fig. 5). Once the liner has been removed, the surfaces of the shell and liner can be assessed for corrosion and the revision operation can proceed as planned. We have successfully used this technique to remove the modular DM liner from a number of different manufacturers and modular metal liners from metal-on-metal THA with similar consistency and success.Fig. 4: A suction device is utilized to grasp the unseated liner for removal.Fig. 5: The liner is removed after it is unseated using the suction device.

Assessing the productivity of coriander under different irrigation depths and fertilizers applied with continuous and pulsed drip systems

Abstract In this study, the authors analyzed the consequences of irrigation management strategies as an essential factor to save water and maintain high crop yields. The present research aimed at comparing coriander (Coriandrum sativum L.), cv. Verdão, yields under fertigation via drip irrigation with a continuous application and in pulses, with 40, 60, 80, 100 and 120% of the crop evapotranspiration (ETc) being recovered. These treatments were distributed in randomized blocks in a 2 × 5 factorial scheme, with three replications, in a greenhouse located at the Federal Rural University of Pernambuco, northeast Brazil (08°01′6.50″ S and 34°56′46″ W, average elevation 6.5 m). The continuous irrigation consisted of the application of water depth in a single daily event, while pulsed irrigation comprised the application of the same irrigation depth split up into five events with a 1-hour interval between pulses. Crop evapotranspiration (ETc) was determined via the water balance by lysimetric drainage. The fertilizers were applied in every watering. The biometric and productivity crop pointed that pulsed irrigation to a mean depth of 58% of the ETc corresponds to the results obtained with the application of the depth equivalent to 100% of the ETc by continuous irrigation, consequently with reduced input costs.

PRODUCTIVITY OF IRRIGATED PEANUT PLANTS UNDER PULSE AND CONTINUOUS DRIPPING IRRIGATION WITH BRACKISH WATER1 2

ABSTRACT Pulse irrigation may be more advantageous for peanut crops than continuous irrigation, when using brackish water. However, studies on pulse irrigation with brackish water considering the environmental conditions of the Northeast region of Brazil using are incipient. Therefore, the objective of this study was to evaluate the effect of using brackish water for pulse and continuous dripping irrigations on the grain yield and production characteristics of peanut (Arachis hypogaea L.) crops. A completely randomized block design with four repetitions was used, in a 6*2 factorial arrangement consisted of six electrical conductivities of the irrigation water (EC; 0.2, 1.6, 2.8, 4.0, 5.2, and 6.4 dS m-1) set by adding NaCl to the irrigation water, which originally had 0.2 dS m-1, until reaching the respective EC; and two irrigation methods (pulse and continuous). The evaluated variables were fresh and dry weights of shoot, 10 grains, pods, grains, and production; number of pods and grains; and percentages of empty pods (EP%) and perfect grains (PG%). The addition of salt to the irrigation water negatively affected all variables studied, except for EP% and PG%. The lowest EP% were found for the pulse irrigation, which increased the pod and grain yields, regardless of the EC of the irrigation water. Under the conditions of the present study, the use of brackish waters with electrical conductivities of up to 2.98 dS m-1 is viable for peanut production.

Development of effective methods and means of normalizing the atmosphere of working zones of open-cast mines

The search for technical solutions for effective air exchange in the space of deep open-cast mines. Since intensive air exchange is necessary to remove and disperse harmful impurities from the open-cast mines, improvement can be achieved mainly by intensifying natural air exchange based on phase transformations of liquids in the lower atmosphere of the working zones of the open-cast mines by creating a positive or negative temperature gradient. New technical solutions are considered that provide support for the sanitary-hygienic parameters of the atmosphere of the deep open-cast mines at the normative level. The formation of an ascending gas stream by a cascade explosion of a fuel-air mixture has the greatest efficiency. The proposed method allows for the implementation of a pulsed ventilation mode with a power of the outgoing air flow of more than 1010 W with a blasting fuel mass of 30 tons. It has been established by analytical and experimental studies that it is advisable to use pulsed fine irrigation systems to intensify air exchange in a deep open-cast mines, using the double effect, ventilating gaseous working zones and cleaning them from harmful substances with the help of a fine aerosol freely floating in space. It is also advisable to use such facilities to reduce peak loads on emissions of harmful substances from the open-cast mines into the environment and to normalize the composition of the atmosphere of the deep open-cast mines. Significant peak emissions of harmful impurities in open-cast mines include mass explosions and situations involving the creation of internal inversion zones. In a computational experiment, there are two water guns: big gun (the water jet range is 200 m, water volume per one cycle is 1000 dm3) and small gun(the water jet range is 100 m, water volume per one cycle is 200 dm3). The results of the experiment indicate greater efficiency in the use of a large water gun for airing the lower horizons of the deep open-cast mines. The use of pulsed fine irrigation systems will allow for carrying out internal technological work at a depth of more than 500 meters using a motorized ore delivery system to transfer points of cyclic-flow technology.

PRODUCTION AND QUALITY OF MINI WATERMELON UNDER DRIP IRRIGATION WITH BRACKISH WATER

ABSTRACT Watermelon plays an important role in Brazilian agribusiness. The objective of present study was to evaluate the effect of different irrigation managements and water salinity levels, on the main productive and postharvest characteristics of mini-watermelon (Citrullus lanatus) cv. ‘Sugar Baby’. The experiment was conducted in a greenhouse in a completely randomized design, arranged in a 2 x 4 factorial scheme, with four replicates. The treatments consisted of two types of irrigation management (conventional and pulse) and four saline levels of nutrient solution of fertigation (2.5; 4.5; 5.5; 6.5 dS m-1). The control treatment corresponded to the electrical conductivity of the nutrient solution prepared with local supply water. The irrigation depth was calculated by the product of reference evapotranspiration and crop coefficient. The number of pulses were defined and fractionated according to the atmospheric demand. The salinity of the fertigation solution affects some variables of the production, but does not reduce the quality of the mini-fruit cv. ‘Sugar Baby’. The management of pulse irrigation shows better results in low salinity, while conventional drip management is more suitable for high salinity (6.5 dS m-1).

Tensiometer‐based irrigation scheduling and water use efficiency of field‐grown strawberries

AbstractIn recent decades, moisture‐based subsurface drip irrigation management strategies lead to water savings while maintaining strawberry yields in open fields. Most soils in the Québec City area are characterized by a high proportion of schist fragments and high hydraulic conductivity, causing substantial water losses following irrigation. Until now, little was known about the efficiency of soil‐moisture‐based irrigation strategies used on moderately coarse‐textured soils and their potential to improve water use efficiency (WUE). The first objective of this study was to test two tensiometer‐based irrigation managements for strawberry plants grown in a conventional system. Since field fumigation is increasingly restricted in field‐grown strawberries, we designed a raised‐bed trough system for use in the field and tested its productivity potential. The two irrigation methods included two treatments using pulsed irrigation: one with a constant irrigation threshold of −15 kPa (Pl), and the other with a variable threshold (−15/−30 kPa) adjusted daily to the predicted crop evapotranspiration (PlETc), in addition to a soilless treatment (SL) using a peat substrate and an irrigation threshold of −5 kPa. Compared to conventional irrigation, the PlETc treatment increased the WUE by 8 to 44% while maintaining marketable yields and fruit quality. Thus, this pulsed irrigation strategy is recommended for strawberry plants grown in clay loam soils. Strawberry plants grown in the soilless system gave 73 to 98% higher early marketable yield than soil cultivation. These results may encourage North American farmers to consider the soilless raised‐bed trough system as a viable alternative to conventional strawberry production systems.

Application of Variable Pulsed Irrigation Algorithm (VPIA) for Runoff Losses Reduction: Case Study of Different Soil Types

The low-pressure sprinklers have been widely used to replace the high-pressure impact sprinklers in the lateral move sprinkler irrigation system due to its low operating cost and high efficiency. However, runoff losses under the low-pressure sprinkler irrigation machine can be significant. This study aims to evaluate the performance of the variable pulsed irrigation algorithm (VPIA) in reducing the runoff losses under low-pressure lateral move sprinkler irrigation machine for three different soil types. The VPIA uses the ON-OFF pulsing technique to reduce the runoff losses by controlling the number and width of the pulses considering the soil and the irrigation machine properties. Also, the VPIA aims to achieve a balance between four critical goals: reduce the runoff losses, deliver the highest possible irrigation depth, ensure a high level of water distribution uniformity in the direction movement, and with the lowest number of pulses. From a wide range of pulses numbers and widths tested applying a certain water depth to three soil types (Loamy Sand, Sandy Loam, Loam), the best solution that satisfies the algorithm goals was selected. A MATLAB code was written to simulate the soil infiltration rate, the sprinkler application rate, and to apply the proposed algorithm. The simulation results show a runoff reduction of at least 91.76% for Loamy sand, 90.7% for Sandy Loam, and 97.79% for Loam soils with a high level of distribution uniformity while delivering the highest possible irrigation depth using the lowest number of pulses.

Pulse drip irrigation and fertigation water depths in the water relations of coriander

ABSTRACT This study was installed to evaluate the effect of pulse drip irrigation under different water depth levels (fertigation) in the main water relations of coriander crop (Coriandrum sativum). The experiment was installed under protected environment conditions, at UFRPE, Recife, Brazil. The experimental design was randomized blocks in a 2x5 factorial scheme, with three replications. Treatments consisted of two application types (continuous and pulsed irrigation), and five water depths with replacement of 40, 60, 80, 100 and 120% of crop evapotranspiration (ETc). Water demand was estimated through water balance using a drainage lysimetry. Six irrigation pulses were defined with a 60-minute-rest interval between two successive applications. Plants irrigated by pulses showed higher water productivity values (fresh and dry mass), higher water content (shoot and root), higher shoot mass production index and lower root mass production index and root-shoot ratio. The reduction of applied fertigation water depths increased plant water stress index. The irrigation pulses used ensured water content able to maintain the crop’s marketable quality. Pulse application in irrigation system increased shoot mass production index and reduced root mass production index.

A prospective comparative study of efficacy of pulse jet irrigation and conventional irrigation techniques in prevention of surgical site infections in laparotomy wounds

Background: Surgical Site Infections (SSIs) are infections of tissues, organs or spaces exposed by surgeons during performance of an invasive procedure and continue to be a major source of morbidity following operative procedures. Wound irrigation is the steady flow of a solution across an open wound surface meant to remove cellular debris and surface pathogens contained in wound exudates or residue from topically applied wound care products.Methods: This prospective comparative study was conducted to compare the effectiveness of Pressurized Pulse Irrigation (PPI) and Standard Irrigation Technique (SIT) in laparotomy wounds. Duration of the study was for a period of 12 months and included 100 consecutive patients undergoing laparotomy.Results: 13% of patients who underwent laparotomy had SSI out of which 9 patients had superficial infection only. 8% of 50 patients who had PPI developed SSI, whereas 18% of those who underwent SIT had SSI. Though PPI had less incidence of SSI, statistically it was insignificant.Conclusions: The study showed a decrease in the incidence of postoperative SSI in both elective and emergency laparotomy wounds irrigated with PPI compared to SIT, though the study was statistically insignificant since the p value was less than 0.005 with a odds ratio of 2.52. The study results suggested that there was decrease in the incidence of SSI in PPI patients and also that it decreases the postoperative stay, morbidity and cost.