Drip Irrigation Technology Research Articles

Drip irrigation technology in semi-arid regions and international cooperation.

Mise au point des connaissances. Description detaillee des systemes et des applications agricoles

One of frontiers in agricultural and environmental biotechnology for the arid regions: Micro-pressure drip irrigation technology theory and practices

With the goal of reducing cost and energy consumption of drip irrigation systems, the relationship between pressure and cost of drip irrigation systems, as well as the feasibility of reducing the operating pressure, were analyzed. The irrigation quality and reliability of micro-pressure drip irrigation systems were also studied. A theory of micro-pressure drip irrigation technology is proposed, and the components of this type of irrigation system are presented. The results indicate that micro-pressure drip irrigation technology is feasible and that it can significantly decrease initial drip irrigation system cost and recurring operating expenses. Micro-pressure drip irrigation can also overcome some of the clogging problems of conventional drip irrigation systems. It is suggested that micro-pressure drip irrigation will be a topic of importance in the future of agriculture and environmental biotechnology.

SUGAR BEET PRODUCTION UNDER DRIP IRRIGATION IN HEAVY CLAY SOIL

Sugarbeet is an important crop in Egypt where overuse of water and agro chemicals is a concern in furrow-irrigated areas. Drip irrigation technology, is not well developed for row crops within the old land. Field experiment was carried out in the Experimental farm, Faculty of Agriculture Kaferelsheik University. Egypt, during the successive season 2005/2006.Therefore, the objective of the present work was evaluation of drip irrigation practice for sugar beet production in Delta region and its effect on soil salinity. The present research includes the following factors:- -Irrigation method : drip and furrow irrigation (main treatments); - Irrigation intervals :Three irrigation intervals for drip, once, twice and triple per week, while the intervals for furrow irrigation was 18 days. (sub treatments), and - Length of furrow and drip lines: Three different of furrow and drip lines were used in the present study ( 20; 30 and 40 m). (sub-sub treatments). The experimental design was split-split plot with four replicates. The important results that obtained from the present work were as follows:- - The average value of total water applied was decreased by about of 1.01 and 0.47 % by using 20 and 30 m as a drip line length comparing with 40 m drip line length. - There was no significant difference among the irrigation treatments on average values of root and sugar yield, Where there are no significant differences in the amount of water added to the unit area during the season. - The highest value of water application efficiency was 91.63 % with drip irrigation, 20 m lateral length and once irrigation per week, while the lowest value was 69.10 % with furrow irrigation. - Increasing number of irrigation per week tended to increase field water use efficiency which the values of field water efficiency were 10.83, 9.73 and 9.12 Kg/m3 by using drip irrigation triple, twice and once per week, respectively. - The increasing values of soil salinity were 0.11, 0.20 and 0.26 dsm-1 for irrigation intervals: triple, twice and once per week, respectively. it could be concluded that the salt accumulation in the root zone can be easily leached by increasing more amounts of irrigation water before the start of the next season.

Rapid Evaluations of Anticlogging Performance of Drip Emitters by Laboratorial Short-Cycle Tests

Emitter clogging is the most annoying problem that restrains the development of drip irrigation technologies, but so far, there have been no effective evaluation methods for the anticlogging performance of drip emitters. In this study, a kind of short-cycle experiment was conducted in the laboratory by mixing sands with various concentrates and particle sizes in irrigation water. Through these tests, the clogging rates that quantitatively represent the clogging status of drip emitters in various experimental conditions were obtained, as well as the variation rules of emitter discharges. The statistical calculation results indicated that the anticlogging performance of predepositing drippers was better than round-flow drip tapes, but less than eddy drip arrows. The discharges of every emitter tested differed from each other and most were lower than nominal discharge rates. However, a few emitters had a contrary result. An important modification had been done for the Christiansen uniformity coefficient to accurately evaluate irrigation uniformity and the clogging status of drip emitters. As a result, a new method of rapid evaluation for the anticlogging performance of drip emitters was proposed.

Technical evaluation and development of low‐head drip irrigation systems in Kenya

AbstractLow‐head drip irrigation technology was recently introduced in Kenya. Imported drip systems are delicate to handle and require special maintenance. No guidelines regarding the optimum combination of lateral length, land slope and operating head were provided. To address the constraints, farmers appealed for technical assistance from research institutions. The objective of the present research was to address the farmers' challenges by evaluating existing low‐head drip irrigation systems to ascertain their performance in terms of water distribution/emission uniformity and to develop simple locally assembled drip irrigation kits. The research work focused on evaluation of emission uniformity and flow variation at different water supply heads, lateral lengths and land slopes. A number of the existing high‐head drip systems were evaluated under low‐head conditions with satisfactory results. Low‐head drip irrigation systems can be used effectively at 0.5–1.5 m water heads without compromising emission uniformity. Based on the technical evaluation, locally assembled drip irrigation systems “dream drip kits” were developed. The paper presents the methodology used for technical evaluation of different drip systems, results of the evaluation and a brief description of the design and development of locally assembled drip irrigation systems. Copyright © 2008 John Wiley & Sons, Ltd.

Evaluation of parameters affecting emitter discharge of some low-head drip irrigation technologies in Kenya

The use of low-head drip irrigation technology is a new development in Kenya due to the need to save water as a resource, among other advantages. However, during its adoption, high variations in emitter discharge occur on various drip tapes when water supply head of about 1.0m is adopted. The objective of this study was therefore to determine the effect of slope, lateral length and water supply head on emitter discharge of the most commonly used low head drip irrigation tapes under field conditions. Four tapes, sold as Chapin, Dream, T-tape, and Typhoon 25, were evaluated. Slopes were varied from 0% to 4%; lateral lengths varied from 5.0m to 20.0m; and water supply heads varied from 0.5m to 2.0m. The results showed that emitter discharges for Chapin were between 0.43 and 0.51 l/hr for 0-2% slopes with standard deviation of 0.05. Higher slopes resulted in increased flow variations as indicated by an emitter discharge of 0.53 l/hr at a standard deviation of 0.12 for the 4% slope. This would lead to low water distribution uniformity at higher slopes. Dream kit was also sensitive to change in slope. However, discharges from T-Tape and Typhoon 25 were less sensitive to change in slope and were suitable even for the 4% slope for 15 m laterals at a head of 1.0 m. Typhoon 25 system could also be adopted for longer laterals without affecting emitter discharges. Emitter discharge characteristic equations were also developed in which emitter discharge varied as the square -root of water supply head for T-tape (R 2 of 97%) and Typhoon 25 (R 2 of 98%) for 0% slope, indicating turbulent flow and less sensitivity to slopes. However, relationships for Chapin and Dream kit systems were nearly linear at R 2 of 96% and 97%, respectively. This indicated that emitter discharge tended towards laminar flow; the tapes were therefore quite sensitive to pressure differences within the respective systems. Keywords : Low head drip irrigation technologies, data points, coefficient of variation, emitter discharge characteristics, and field conditions Journal of Agriculture, Science & Technology Vol. 9 (1) 2007: pp. 28-43

On farm evaluation of the effect of low cost drip irrigation on water and crop productivity compared to conventional surface irrigation system

This on-farm research study was carried out at Zholube irrigation scheme in a semi-arid agro tropical climate of Zimbabwe to determine how low cost drip irrigation technologies compare with conventional surface irrigation systems in terms of water and crop productivity. A total of nine farmers who were practicing surface irrigation were chosen to participate in the study. The vegetable English giant rape ( Brassica napus) was grown under the two irrigation systems with three fertilizer treatments in each system: ordinary granular fertilizer, liquid fertilizer (fertigation) and the last treatment with no fertilizer. These trials were replicated three times in a randomized block design. Biometric parameters of leaf area index (LAI) and fresh weight of the produce, water use efficiency (WUE) were used to compare the performance of the two irrigation systems. A water balance of the inflows and outflows was kept for analysis of WUE. The economic profitability and the operation, maintenance and management requirements of the different systems were also evaluated. There was no significant difference in vegetable yield between the irrigation systems at 8.5 ton/ha for drip compared to 7.8 ton/ha in surface irrigation. There were significant increases in yields due to use of fertilizers. Drip irrigation used about 35% of the water used by the surface irrigation systems thus giving much higher water use efficiencies. The leaf area indices were comparable in both systems with the same fertilizer treatment ranging between 0.05 for surface without fertilizer to 6.8 for low cost drip with fertigation. Low cost drip systems did not reflect any labour saving especially when manually lifting the water into the drum compared to the use of siphons in surface irrigation systems. The gross margin level for surface irrigation was lower than for low cost drip irrigation but the gross margin to total variable cost ratio was higher in surface irrigation systems, which meant that surface irrigation systems gave higher returns per variable costs incurred. It was concluded that low cost drip systems achieved water saving of more than 50% compared to surface irrigation systems and that it was not the type of irrigation system that influenced the yield of vegetables significantly but instead it is the type of fertilizer application method that contribute to the increase in the yield of vegetables. It was recommended that low cost technologies should be used in conjunction with good water and nutrient management if higher water and crop productivity are to be realized than surface irrigation systems.

Pepsee systems: grassroots innovation under groundwater stress

Drip irrigation, in its various forms, is the dominant mode of micro-irrigation in India. The benefits of these technologies in water scarce regions have been widely studied all over the world. A review of literature on dripirrigation technologies strongly suggests that there are significant financial, economic and social benefits in the adoption of these technologies. However, the spread of drip irrigation in the Indian context has been far below potential and expectations. In the Maikaal region of Central India, a grassroots innovation called ‘Pepsee’ has become a popular choice for farmers. At less than half the cost of conventional drip systems, this innovation promises comparable returns. What is most interesting is that while government and non-government agencies have struggled to promote water-saving technologies across the country, the people in this area have adapted and adopted these technologies on their own. This paper looks at the various aspects of this grassroots innovation, its spread, adoption behavior and impacts. The authors find that while Pepsee and other water-saving technologies do lead to farm level improvements in water efficiency, they will not contribute to system level ‘real’ water saving unless a favorable policy environment encourages their adoption on a large scale.

Comparison of HYDRUS-2D Simulations of Drip Irrigation with Experimental Observations

Realizing the full potential of drip irrigation technology requires optimizing the operational parameters that are available to irrigators, such as the frequency, rate, and duration of water application and the placement of drip tubing. Numerical simulation is a fast and inexpensive approach to studying optimal management practices. Unfortunately, little work has been done to investigate the accuracy of numerical simulations, leading some to question the usefulness of simulation as a research and design tool. In this study, we compare HYDRUS-2D simulations of drip irrigation with experimental data. A Hanford sandy loam soil was irrigated using thin-walled drip tubing installed at a depth of 6 cm. Three trials (20, 40, and 60 L⋅m-1 applied water) were carried out. At the end of each irrigation and approximately 24 h later, the water content distribution in the soil was determined by gravimetric sampling. The HYDRUS-2D predictions of the water content distribution are found to be in very good agreement with the data. The results support the use of HYDRUS-2D as a tool for investigating and designing drip irrigation management practices.

The Economics of Water‐Conserving Technology Adoption in Tunisia: An Empirical Estimation of Farmer Technology Choice

Economic theory tells us that increases in the relative prices of natural resources should cause farmers to switch to techniques that use fewer farming resources. The adoption of resource-conserving technology is one possible response that can lead toward a more environmentally sustainable outcome. Do farmers respond to changes in natural resource prices and quality by adopting available resource-conserving technology? This article investigates a case study of decisions made by Tunisian farmers as to whether or not they should invest in water-conserving drip-irrigation technology as a function of natural resource prices and quality along with farm and farmer characteristics. In contrast to many studies of technology adoption this work uses both the standard revealed preference analysis of who adopts and a direct elicitation of the reasons for adoption or nonadoption by farmers. By reviving an ancient methodology—the direct question—to elicit real preferences from farmers the research goes beyond the restrictive assumptions of the commonly used random utility models. The combination of these techniques allows triangulation on the causes of technology adoption and helps insure that the results are more than a statistical artifact. (excerpt)

Impacts of Recent Climate Trends on Agriculture in Southwestern Ontario

In this paper, precipitation, temperature and crop water deficit during the past 80 years in southwestern Ontario are reviewed in terms of their impacts on the region’s present and future field-crop production. Although the generally drier (average annual precipitation ≈ 750 mm) and warmer (average annual air temperature ≈ 9.5 °C) weather in the region during the last decade produced greater average annual crop water deficits (≈ 150 mm yr−1) than during the previous 30 to 40 years, the situation is not as severe as during the 1930s. It is likely, however, that the negative impacts of climate on the region’s field-crop production (yields often ≤ 50% of potential) are greater now than ever before because of more intensive agriculture, fewer pastures/wetlands/woodlots, and greater water demands by increasing population and industry. To mitigate the current negative weather effects, the region’s field-crop sector is adopting drip irrigation technologies (more efficient than the traditional overhead gun systems) which have been shown in recent trials to increase tomato yields by 50–80% over those not irrigated. In addition, combined drainage-surface runoff-irrigation technologies (’closed loop’ water management systems) are being developed which can increase corn and soybean yields by up to 90% and 50%, respectively, while simultaneously decreasing agrochemical and sediment degradation of the off-field environment. If the current climate trend persists, it may be necessary to develop new drought- and heat-resistant field crops as well as updated guidelines for nutrient and pest management.

Predicting drip irrigation use and adoption in a desert region

The possibility that drip irrigation technology could increase yields, reduce the incidence of crop diseases, and improve fruit quality has been identified as a critical research issue for the New Mexico chile pepper industry. Numerous hypotheses have been expressed regarding the low incidence of drip irrigation usage among New Mexico farmers. A survey of farmers was conducted in 1999 to assess commercial chile pepper producers’ attitudes toward and knowledge of drip irrigation technology. The survey data were used in logistic regression models that predict current high-tech irrigation system usage, drip irrigation usage, and plans for future drip irrigation adoption by chile pepper producers. The results of this research provide information useful to extension personnel, other researchers, and chile industry members. Results also raise questions about the impact of widespread drip irrigation adoption on multi-user irrigation systems, such as those found in New Mexico.

Adoption and Diffusion of Drip Irrigation Technology: An Econometric Analysis

A growing body of literature on "threshold" adoption models argues that adoption and diffusion patterns of a new technology are the result of explicit maximizing behavior of a heterogeneous population. Unlike the views of "epidemic" models of Z. Griliches and E. Mansfield, where diffusion is considered as a process of imitation and its speed is affected by profitability and other economic considerations alone,1 the threshold approach requires identification of the various dimensions of heterogeneity in the population that are relevant for the adoption of specific technology and incorporates them in the analytical study.2 M. Caswell and D. Zilberman have identified land quality and well depth as important factors in the choice of irrigation technology.3 Therefore, economic analyses of adoption and diffusion of irrigation technology choices should explicitly incorporate physical (engineering and agronomic) and irrigation-specific features of the new technology, such as irrigation efficiency and capital and equipment costs, as well as locational characteristics such as land quality, water quality, and so on, in addition to economic factors. It is important for farmers, manufacturers of irrigation equipment, and policymakers to understand the conditions under which a specific technology, such as drip, is .desirable and is likely to be adopted, as well as the forces that affect the diffusion. Understanding the adoption patterns of drip irrigation technology is required for the formulation of water, energy, and land management policies. Furthermore, it is not sufficient to know whether drip irrigation is likely to be adopted in a particular field; it is equally important to determine to what extent it will be used.

Adoption of drip irrigation in cotton: The case of kibbutz cotton‐growers in Israel

Abstract The subject of technological innovations in agriculture has attracted considerable attention among development economists because new technologies offer opportunities to increase income substantially. Immediate and uniform adoption of agricultural innovations is quite rare. Some innovations have been well received while others have been adopted by only a very small group of farmers. The aim of this paper is to identify, estimate and explain the parameters which promote the adoption and speed the rate of diffusion of drip irrigation technology in cotton‐growing. Using cross‐section time‐series regression models, the analysis was applied to a sample of 38 kibbutz cotton‐growers in two regions of Israel. It was found that profitability is the major motive for adoption of drip irrigation in cotton by a profit‐maximizer kibbutz farm. Additional significant explanatory variables which affect the rate of diffusion are detailed in the paper.

Use of a Portable Pumping and Filtering Unit for On-farm Plastic Mulch–Drip Irrigation Demonstrations

Abstract One of the primary missions of the Agricultural Extension Service in each state is to reach agricultural producers with new technology. One of the best educational resources available to accomplish this mission is the on-farm demonstration program. Demonstrations provide a vital link between the researchers and the agricultural producers. The use of the portable pumping and filtering unit in an extension on-farm demonstration provides growers with the opportunity to observe plastic-mulch–drip-irrigation technology and also allows extension specialists to provide valuable training to county extension personnel.

REGULATION OF THE HYDROTHERMAL REGIME OF EARLY POTATO PLANTINGS

The article deals within matters of the mineral elements removal with drainage water on reclaimed lands, on the Central Russian and Volga Uplands in an unstable hydrothermal regime. The reuse of drainage water for irrigation with the use of sprinkler and drip irrigation are assessed. Taking the example of drip irrigation is being considered the possibility of the most effective influence during the plant growing season on the hydrothermal regime of the soil and the ground-level pollution both in a dry year and in case of excessive rainfall. The features of drip irrigation technology with use of a mulching screen made of a membrane film with selective moisture permeability are described. The proposed method of drip irrigation of early varieties of potatoes due to more intensive condensation of water vapor on the inner layer of the screen allows to maintain a more stable daily soil temperature. The screen opaqueness inhibits the germination of weeds in wet row spacing, capillary humidification of the tuber formation zone in combination with the screen permeability for air prevent anaerobic processes in this part of the furrows and its overmoisturazing. The application of the proposed method of potato cultivation during drip irrigation provides the rational use of rainfall, increasing the uniformity of field moistening and reducing moisture loss, and also prevents the soil overwetting in the zone of tuber formation and provides aeration of the soil under the screen.