Pressurized Irrigation Systems Research Articles

Effects of the Agri-environmental Program Implemented in Sultan Reeds Area of Kayseri, Turkey

This study was initiated to evaluate the effects of agri-environment program implemented in the Sultan reeds area of Kayseri province, Turkey. The specific objectives of the study were to compare the farmers who enrolled in the program with those who didn’t enroll regarding their application of different sustainable agricultural practices, and to determine factors affecting their enrolment in the program. The main comparative indicators were selected from different sustainable agricultural practices either promoted by the agri-environmental program or not promoted but considered very useful for the locality. Two stratified samples of farmers (enrolled and not enrolled) were selected based on their farm size. Chi-square tests of independence were used to compare farmers on the selected sustainable agricultural practices. Logistic regression model was used to determine factors affecting the enrolment of the agri-environment program. The findings of the chi-square test showed that enrolled farmers use grow more forage legumes, are more conscious about pesticides use and chemical applications, and they use more pressurized irrigation systems. Findings of the logistic regression model sowed that using rental land negatively, but contacts with extension personnel, and using long term loans for farming investments positively influenced the enrolment of the agri-environment program. Governmental effort must concentrate on these issues when promoting agri-environmental programs in the region.

Linear mixed modeling and artificial neural network techniques for predicting wind drift and evaporation losses under moving sprinkler irrigation systems

Pressurized irrigation systems, center pivots, and linear moves are used worldwide on a large scale. Accurate predictions of wind drift and evaporation losses (WDEL) could help in improving the system’s uniformity and efficiency. The current study evaluates data analysis techniques for accurately estimating WDEL under moving sprinkler irrigation systems. A total of 72 experiments (2015–2017) were conducted at the research and extension center in Prosser, WA, under a wide variety of climate conditions. Two data analysis techniques, namely linear mixed modeling (LMM) and artificial neural networks (ANN), were used to identify the significant drivers of WDEL from the given weather-related inputs. Four published datasets were also used to check the generalization capabilities of the developed models. The results revealed an average of ~ 20% WDEL under Prosser, WA, conditions. Vapor pressure deficit and wind speed were the only significant weather variables at a 0.05 level of significance. Both in training and in testing, the ANN models (root mean squared error (RMSE = 2%)) worked better than the LMM (RMSE = 5%). Testing results revealed the high generalization and predictive power of ANN models with a RMSE of 1% for the (Yazar 1984) datasets. The best LMM model was with the Sanchez et al. (2011) dataset with a RMSE of 14%. The above results showed that ANN models can be used to accurately predict WDEL. This should help in further research for efficiency improvements in sprinkler irrigation systems.

Efficacy evaluation of a cordless ultrasonic unit in achieving reduction of bacterial load within a root canal system as compared to a conventional ultrasonic unit and negative pressure irrigation

IntroductionIncrease in efficacy during root canal irrigation may contribute to better treatment outcomes. This study investigated the efficacy of ultrasonic and negative pressure irrigation systems using sodium hypochlorite (NaOCl) in the reduction of bacterial load in human teeth.One hundred thirty-one single-rooted teeth were cleaned and shaped, autoclaved, and incubated with E. faecalis. Teeth were randomly assigned to three experimental groups (n = 40) and treated in the presence of 1% sodium hypochlorite using EndoUltra cordless ultrasonic, conventional ultrasonic, and Endovac negative pressure irrigation. Syringe irrigation controls were treated with 1% sodium hypochlorite and phosphate-buffered saline via side-vented needle irrigation. All groups with NaOCl received 5% sodium thiosulfate neutralization for 5 min after treatment. Samples of root canal fluid and dentin chips were acquired from canals before and after treatment, incubated on BHI agar, and colony forming units categorized according to quantity. Wilcoxon rank-sum and Bonferroni tests were used for statistical analysis. p values less than 0.05 were considered significant.ResultsEndovac group was significantly better in eliminating bacteria from the root canals than 1% NaOCl (p = 0.006) and PBS syringe irrigation (p = 0.015). However, it was not significantly different from the two ultrasonic groups (p > 0.05). Both ultrasonic groups showed better performance than 1% NaOCl and PBS syringe irrigation, however, not statistically significant (p < 0.03). There was no significant difference between the two ultrasonic devices (p > 0.05).ConclusionEndoVac may be an important tool for bacterial load reduction in oval canals.

Site Selection of Different Irrigation Systems Using an Analytical Hierarchy Process Integrated with GIS in a Semi-Arid Region

Site selection of different irrigation systems can lead to higher water productivity in drought conditions. The present study intends to evaluate suitable regions along the Izeh plain (Iran) for different pressurized and gravitational irrigation systems using Analytical Hierarchy Process (AHP) based on Geographic Information System (GIS). To that end, a variety of inputs such as climate, topography, skilled labor and system costs, etc. were identified and classified into two main categories of socio-economic and environmental criteria. Each criterion was subdivided into several criteria to make the site selection more specific. A matrix of the pair-wise comparison was, in turn, used to compare these criteria and sub-criteria, and to evaluate them based on their relative importance based on the region’s suitability for different irrigation system alternatives. Geographical layers were then obtained for each sub-criterion to select the most suitable sites for different irrigation systems in the study area. Pressurized irrigation systems including wheel move irrigation system, drip irrigation system and solid-set sprinkler irrigation system, together with gravitational irrigation systems consisting of surface irrigation system, and low-pressure irrigation system were considered as irrigation system alternatives during the site selection process in this study. The result map of site selection for different alternatives showed that surface irrigation, drip irrigation and low pressure systems were the best irrigation system alternatives for the region studied.

Evaluation of Negative Economic-Environmental Externalities of Overextraction of Groundwater.

In recent decades, increased extraction of groundwater for human and agriculture consumption has led to a substantial drop in groundwater level in large areas of across the world. Declining groundwater levels is a serious problem in itself and has multiple economic, social, cultural, political, security-related, and environmental externalities. The negative economic-environmental externalities of overextraction of groundwater in the Orzouiyeh plain in the Kerman Province, Iran, were evaluated using methods such as replacement cost, production function, market prices, shadow price, and the value of the input marginal product. After evaluating externalities, the Positive Mathematical Programming method was used to evaluate different water policies to reduce the consumption of groundwater. The total economic losses due to the externalities were calculated to equal 2.8 U.S. million dollars. The damages caused by environmental externalities were calculated to equal 436.1 U.S. million dollars. The results related to the positive planning model show that the best policy among different options, such as deficit irrigation policy or combined policies, involves implementation of pressurized irrigation systems.

Design of solar photovoltaic pressurized drip irrigation pumping system at al-salman district in samawa governorate

The seasonal climate changes have direct effects on determination of crop water requirement, irrigation scheduling and the potential of solar energy generation to operate the pumping system for watering crops. This research paper studied the technical evaluation of solar pumping and pressurized drip irrigation systems to investigate the recommended water required for suggested tomatoes crop in area of (one hectare) at AL-Salman district using measured climatic data from AL-Salman Agro-meteorological weather station for a period (2013-2017). The maximum average monthly of solar radiation was 7.6 kWh/m&lt;sup&gt;2 &lt;/sup&gt;at June in all the years of recording data, while the minimum average monthly value was 3.37kWh/m&lt;sup&gt;2&lt;/sup&gt; at December where the sun at lowest point across the sky. The annual average hours of peak sun that corresponds to the operation time of the pumping system at maximum water consumption was calculated at eight months from March to October with a value of 7.2 hours/day, while it was 5.2 hours/day during the other four months (January, February, November and December). The Solar pumping sizing based on H-Q performance curve of a maximum flow rate of 64.45 m3/h and pump capacity of 16.79 kW with compounds motor pump efficiency of 61.2%. The total water production was 230000 m³/per year which indicates compatible overall system design and adequate to irrigate more planting land with same or other crop types.

Investigation of different sodium hypochlorite volumes, concentrations and times of irrigation in endodontic therapy: a systematic review

Investigation of different sodium hypochlorite volumes, concentrations and times of irrigation in endodontic therapy: a systematic review

Agriculture in semiarid ecosystems favors the increase fossorial rodent’s activity in La Pampa, Argentina

Technological advancements and new production systems modify the conditions of natural environments. Transformations in an arid landscape caused by alfalfa cropping under pressurized irrigation systems have generated a conflict between farmers and Azara’s tuco-tucos (Ctenomys azarae). Mounds produced by this species damage the alfalfa cutting equipment, reduce the lifespan of harvesting machinery, and results in high production costs. The goal of this study was to determine the production variables that influence density and spatial distribution pattern of Azara’s tuco-tucos’ mounds within the alfalfa plots under center-pivot irrigation. We assessed the frequency and distribution of Azara’s tuco-tuco mounds in plots under center-pivot irrigation during two alfalfa crop seasons. Using generalized linear models, we determined that the total number of mounds and the number of active mounds were positively related to alfalfa’s stand age and height. However, there are likely other variables that we did not include that should be considered to reduce the number of mounds and, therefore, mitigate damage. Considering the emerging implementation of new agricultural practices and the distribution area of the genus Ctenomys, this unprecedented work in Latin America contributes necessary and important information for better pest control management.

Head loss in laser-perforated thin-walled polyethylene pipes for irrigation

ABSTRACT For reducing fixed and operational costs in pressurized irrigation systems, thin-walled polyethylene pipes with laser-perforated orifices are manufactured to operate under low pressure (up to 100 kPa). Hydraulic characterization of these materials is essential for designing irrigation systems. Considering the material elasticity and the thin wall thickness (about 200 μm), the internal diameter of these pipes may vary according to the operating pressure, resulting in changes of head losses. The purpose of this study was to analyze the head loss in flexible pipes with laser-perforated orifices, and to estimate the maximum length of laterals based on criteria of water distribution uniformity. Non-perforated pipe samples were tested to obtain equations of friction loss. Equations were fitted as a function of flow rate and pressure head at the pipe inlet, and, alternatively, the Darcy-Weisbach equation was modified considering the diameter expressed as a power-law function of pressure head. The equation of head loss as a function of flow rate and pressure head provided proper estimations and considered effects related to changes in the diameter of plastic pipes due to variations in the pressure head. The Darcy-Weisbach equation can be employed for estimating head loss in flexible pipes, whose diameter varies due to pressure, but the diameter must be calculated as a function of the pressure head at the lateral inlet.

Pressure-discharge and Hydraulic Gradient along the Lateral of the Drip Irrigation System for Okra

Micro irrigation system should ensure relatively same amount of water to each plant along the total length of lateral line. In general, the drip irrigation systems are low to medium operating pressure head systems with a pressure requirement in range of 0.5 kg/cm2 to 2.5 kg/cm2 depending on the area irrigated and field layout geometry. However, since these systems are pressure irrigation systems which require appropriate operating pressure heads to deliver the required rates of flow, the inevitable frictional head losses are to be compensated for maintaining uniformity in water application. Hence, the hydraulic gradient compensation needs to be achieved by some viable mechanism so that the inequality in pressure heads and discharges can be eliminated or minimized. The crop production will have its maximum yield and water use efficiency only one the water distribution uniformities at its the highest. Hydraulic gradient compensation assumes a vital role in compensating the operating pressure heads as well as the emitter discharges. The hydraulic gradient compensated drip lateral layout registered high order of water distribution uniformity in the range of 97.8% and irrigation usage efficiency in the range of 17.98 kg/ha/mm to 20.69 kg/ha/mm for 2 lph emitter arrangements.

Assessing the ground water quality for pressurized irrigation systems in Kerman Province, Iran using GIS

Ground water quality assessment is important for use in various industries, for drinking, and for agriculture. This paper tries to evaluate the quality of ground water used in agricultural sector in Kerman province. Kerman province, with an area of 180,726 km2, is one of the largest provinces of Iran. Agriculture is common in this region and ground water is mostly used for irrigation. Using zonation with GIS and standard tables, it was tried to examine the use of this ground water in drip and sprinkler irrigation systems. The results of zoning water quality in agricultural sector showed that water quality is classified into three groups of good, moderate, and unsuitable according to Wilcox classification. In term of TDS, a small amount of water has limitations and in term of EC, high amount of water is unauthorized. Also, the results of zoning showed that for drip irrigation, a small amount of water is unallowable in terms of CL and TDS, but regarding pH, the water of the total area is allowable. So, if the sprinkler irrigation system is implemented, in terms of acidity the total area has acceptable level, but in term of sodium and chlorine levels will be unauthorized.

Perturbation Indicators for On-Demand Pressurized Irrigation Systems

The perturbation in hydraulic networks for irrigation systems is often created when sudden changes in flow rates occur in the pipes. This is essentially due to the manipulation of hydrants and depends mainly on the gate closure time. Such a perturbation may lead to a significant pressure variation that may cause a pipe breakage. In a recent study, computer code simulating unsteady flow in pressurized irrigation systems—generated by the farmers’ behavior—was developed and the obtained results led to the introduction of an indicator called the relative pressure variation (RPV) to evaluate the pressure variation occurring into the system, with respect to the steady-state pressure. In the present study, two indicators have been set up: The hydrant risk indicator (HRI), defined as the ratio between the participation of the hydrant in the riskiest configurations and its total number of participations; and the relative pressure exceedance (RPE), which provides the variation of the unsteady state pressure with respect to the nominal pressure. The two indicators could help managers better understand the network behavior with respect to the perturbation by defining the riskiest hydrants and the potentially affected pipes. The present study was applied to an on-demand pressurized irrigation system in Southern Italy.

Sensitivity Indicator for Pressurized Irrigation Distribution Systems

Providing adequate pressure at the hydrant is an issue of great importance in the operation of pressurized irrigation distribution systems (PIDS). The hydraulic performance of these systems can be quantified by selected performance indicators to describe the performance of an irrigation system with regard to the objectives set for that system. Several indicators have been developed and used so far for the performance analysis of pressurized irrigation systems. However, none of them provides a comprehensive definition of the sensitivity of operating hydrants to the variation in the upstream discharge. The objective of this study is to develop an indicator that can quantify the sensitivity of a hydrant to the changes occurring upstream of an irrigation system. A new definition of the indicator is proposed, by considering the changes in the hydrant reliability to the changes in the upstream discharge. In other words, the sensitivity of a hydrant is simulated on the basis of the variation of its reliability to satisfy the required pressure for adequate on-farm service. This concept was applied to a case study in Italy and it showed the importance of the sensitivity indicator as defined herein in the decision-making process for proper operation of pressurized irrigation systems.

A financial comparative study of solar and regular irrigation pumps: Case studies in eastern and southern Iran

While pressurized irrigation systems can be effectively powered using renewable energy sources, no serious related study is found in Iran in this regard. In the present study, in two different climatic conditions in Iran, development of small-scale solar irrigation were evaluated financially and compared with that of systems powered by the fossil fuel and electricity grid. Financial analysis of systems was provided using life cycle cost (LCC) method. Results showed that in the case of 4.5 and 5.5 kW pumps (for citrus orchard and a vineyard, respectively), photovoltaic irrigation pumps with batteries for energy storage are comparable to the systems in which the electricity used to drive pumps is transmitted through 0.25 km and 1.8 km private lines. It was concluded that, generally, if the required power of irrigation pumps exceeds 3 kW, the electricity supplied by a private power transmission line is more affordable than in-situ generated photovoltaic electricity, if the length of transmission line is less than 2 km. It was also observed that for required power less than 4.5 kW, photovoltaic energy is somewhat comparable to fossil fuel. As Iran is dependent upon its highly subsidized fossil fuels, the financing of solar irrigation projects will not be possible without the help of new policies and laws.

Calibration and Global Sensitivity Analysis for a Salinity Model Used in Evaluating Fields Irrigated with Treated Wastewater in the Salinas Valley

Treated wastewater irrigation began two decades ago in the Salinas Valley of California and provides a unique opportunity to evaluate the long-term effects of this strategy on soil salinization. We used data from a long-term field experiment that included application of a range of blended water salinity on vegetables, strawberries and artichoke crops using surface and pressurized irrigation systems to calibrate and validate a root zone salinity model. We first applied the method of Morris to screen model parameters that have negligible influence on the output (soil‐water electrical conductivity (ECsw)), and then the variance-based method of Sobol to select parameter values and complete model calibration and validation. While model simulations successfully captured long-term trends in soil salinity, model predictions underestimated ECsw for high ECsw samples. The model prediction error for the validation case ranged from 2.6% to 39%. The degree of soil salinization due to continuous application of water with electrical conductivity (ECw) of 0.57 dS/m to 1.76 dS/m depends on multiple factors; ECw and actual crop evapotranspiration had a positive effect on ECsw, while rainfall amounts and fallow had a negative effect. A 50-year simulation indicated that soil water equilibrium (ECsw ≤ 2dS/m, the initial ECsw) was reached after 8 to 14 years for vegetable crops irrigated with ECw of 0.95 to 1.76. Annual salt output loads for the 50-year simulation with runoff was a magnitude greater (from 305 to 1028 kg/ha/year) than that in deep percolation (up to 64 kg/ha/year). However, for all sites throughout the 50-year simulation, seasonal root zone salinity (saturated paste extract) did not exceed thresholds for salt tolerance for the selected crop rotations for the range of blended applied water salinities.

Factors Determining the Adoption of the Pressurized Irrigation Systems by Farmers in Ardabil Province

Purpose- One of the most important strategies facing drought and agriculture water shortage in North-West Iran is developing pressurized irrigation systems (PISs). In this regard, the present study aims to investigate the factors determining the adoption of the PISs by farmers in Ardabil Province. Design/methodology/approach- First, by drought zoning of Ardabil Province (by SPI method and GIS software), three regions including regions with mild, moderate and severe drought levels were determined. In the second step, using multi-stage cluster sampling, adopter and non-adopter farmers of the PISs were selected from three regions of study (n= 415). Also, the logistic regression was used to determine the affective and distinctive factors of farmers' groups. Findings- According to the results of logistic regression analysis, the predictive power of model was 0.622 and the sensitivity of the regression model to determine the model validation was obtained as 85.8%. Also, from among 17 factors of study, 7 factors of education level, farm income, knowledge about the PISs, the infrastructure for PISs, the effect of local weather conditions, the trust towards the optimality of PISs and the improvement in farm water management, positively impacted on the adoption and use of PISs. Among effective factors, knowledge about the PISs (Wald: 32.676), the trust towards the optimality of PISs (Wald: 27.855) and the infrastructure for PISs (Wald: 21.648) were the most important factors predicting to the decision to adopt and use PISs among farmers. Research limitations/implications- Since the study was carried out in a large area of the province, accessing the farmers and experts in the Ardabil Province was difficult and time consuming. Practical implications- The agricultural extension and education programs and PRA method, can provide the basis for the adoption of PISs among most of the farmers. Also, the infrastructure programs for the implementation and setting up of PISs are the priority of governmental projects to develop the PISs in the regions of the study. Originality/value- It seems that identifying and providing the necessary infrastructure for implementing pressurized irrigation programs should be based on the scientific needs assessment of the agricultural fields’ conditions in different regions. Also, proper the appropriate government funding and financial support for the appropriate infrastructure of PISs will increase the willingness of farmers to adopt and use of the PISs.

A 2D curvilinear coupled surface–subsurface flow model for simulation of basin/border irrigation: theory, validation and application

Despite the development of pressurized irrigation systems in the second half of the twentieth century, surface irrigation continues to be the most used system in the world. Computer tools are required to support performance improvements leading to its sustainability. A simulation model of basin/border irrigation is presented in this paper combining two-dimensional overland hydraulics based on Saint–Venant equations with three-dimensional infiltration based on the mixed form of Richards’ equation. The coupling of these equations is attained by enforcing continuity of pressure at the soil surface. The model applies a finite-volume approach using the diffusion-wave approximation form of the shallow water equations. Water flow on undulated topographies is simulated using a non-orthogonal curvilinear coordinate system. An underrelaxed-modified Picard iteration algorithm is used for Richards’ equation, and an underrelaxed Picard iteration algorithm is used for Saint–Venant equations. The model was validated using experiments from the literature. Model performance was robust and accurate, even in complex theoretical cases with strong soil-surface undulations. Mass conservation was judged satisfactory in all cases, with the long-term ratio of mass balance error in the order of 10−2 in the most complex simulations. Soil type, mesh non-orthogonality, and the interaction of these variables had a strong effect on CPU time. Additional research will be required to transform this simulation model into an operational tool for surface irrigation. Attention will need to be paid to additional surface irrigation systems, soil types, and the optimization of computational speed.

Multi-Crop Production Decisions and Economic Irrigation Water Use Efficiency: The Effects of Water Costs, Pressure Irrigation Adoption, and Climatic Determinants

In an irrigated multi-crop production system, farmers make decisions on the land allocated to each crop, and the subsequent irrigation water application, which determines the crop yield and irrigation water use efficiency. This study analyzes the effects of the multiple factors on farmers’ decision making and economic irrigation water use efficiency (EIWUE) using a national dataset from the USDA Farm and Ranch Irrigation Survey. To better deal with the farm-level data embedded in each state of the U.S., multilevel models are employed, which permit the incorporation of state-level variables in addition to the farm-level factors. The results show higher costs of surface water are not effective in reducing water use, while groundwater costs show a positive association with water use on both corn and soybean farms. The adoption of pressure irrigation systems reduces the soybean water use and increases the soybean yield. A higher EIWUE can be achieved with the adoption of enhanced irrigation systems on both corn and soybean farms. A high temperature promotes more the efficient water use and higher yield, and a high precipitation is associated with lower water application and higher crop yield. Intraclass correlation coefficients (ICC) suggest a moderate variability in water application and EIWUE is accounted by the state-level factors with ICC values greater than 0.10.

The Identification of Factors Affecting the Use of Pressurized Irrigation Systems by Farmers in Iran

Climate change and water scarcity are the most important challenges of the agricultural sector, and pressurized irrigation systems (PISs) are one of the most significant ways to improve agricultural water productivity. The main purpose of this research was to identify the factors affecting the use of PISs by farmers. The statistical research population was a total of 2396 Iranian model farmers. The Cochran formula was used to determine the number of statistical samples. Accordingly, this comprised 331 people. The methodology of the study was mixed method research. The structural equation modeling technique, Mann–Whitney U, and Kruskal–Wallis tests were used to test the hypotheses. The results showed that the personal characteristics, tendency, attitude, self-efficacy, subjective norms, governmental support, environmental tensions, and technological features were the most important factors which influenced the farmers. It was found that all of these variables had a positive and significant relationship with the using of PISs by farmers, and they were able to predict 52% of the behavioral changes (R2) of the farmers. Among these variables, the attitude, with a path coefficient (β) of 0.48, had the highest impact on the using of PISs by the farmers.

English

Water demand is continuously increasing worldwide parallel with the growing population. Because agriculture is considered as a significant water consumption sector, water demand in this sector may be reduced by improving water use efficiency to make farming more irrigated and sustainable. This study was planned to estimate the technical and water use efficiency of hazelnut growers in Carsamba district of Samsun, Turkey. For this purpose, a sample of 350 farmers representing this district was drawn in advance. Hazelnut growers were identified from this sample, and they were contacted in Spring 2016 season to administer a questionnaire regarding their farming practices, particularly irrigation. Results of the study showed that only 27.70% hazelnut growers were irrigating their hazelnut orchards by a specific source of water (canal, reservoir, or groundwater). Among these farmers who used irrigation for hazelnuts only 13.40% adopted the pressurized irrigation systems, namely sprinkler or drip irrigation, and the remaining farmers were using the floating irrigation method. The adopters used lower quantity of water and received higher yields as compared to non-adopters. Similarly, they were 98% technically efficient, and their water use efficiency level was 78%. The same figures for non-adopters were 94 and 54%, respectively. It was concluded that both of the two groups were technically efficient, but hazelnut growers may focus on water saving by adopting the pressurized irrigation systems which reduce water wastage and enable the growers to use water sources efficiently. Key words: Water use efficiency, technical efficiency, pressurized irrigation, sprinkler irrigation, drip irrigation, floating irrigation, hazelnut farming, data envelopment analysis (DEA). &nbsp