Session 27. One-On-One Poster Presentations
Economic Analysis of Microirrigation of Pomegranate in India
S. K. Bendale, H. S. Chauhan and K. N. Shukla
Field survey studies were conducted to study the economics of drip irrigation on pomegranates in Sangli area of Maharashtra State, India. The cost of installation was found to be Rs.30934 ($997) per ha. Total cash outflow and inflow per ha at the end of ten years, was found as Rs.52588 ($1699) and Rs.250,565 ($8082) respectively. Net cash inflow per ha was found to be Rs.197,976 ($6386) at the end of ten years and benefit cost ratio was estimated as 2.12.
Keywords: Pomegranate, Microirrigation, Drip/Trickle irrigation, Cost analysis
Abstract taken from paper found on pages 818 to 823 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Studies on Drip Irrigation Installation for Grapes Around Hyderabad (India)
G. Ravi Babu, K. N. Shukla and H. S. Chauhan
Studies were conducted on yield, water requirement and economics of installation of two varieties of grapes (Anab-e-Shahi and Thompson Seedless) planted around Hyderabad, India. The studies were based on field survey of farmers, collection of information from industries, and analysis of actual installation of drip irrigation systems in the farmers fields. Based on the studies, it was found that the yield of grapes (Anab-e-Shahi) ranged between 27.181 and 33.375 t/ha for 2 to 8 years age of the crop. The quantity of water applied per year per hectare ranged between 6042.0 and 7774.8 m3 for 2 to 8 years age of the crop. The average initial investment on the drip system per hectare was found to be Rs. 33,190.00 ($1070). The total cash outflow and total cash inflow per hectare for this grape variety at the end of ten years, was found to be Rs. 1,98,641.00 ($6407) and Rs. 14,07,455.00 ($45401) respectively. Net cash inflow per hectare was found to be Rs. 12,08,814.00 ($38994) at the end of ten years. The yield of the other variety of grape (Thompson Seedless) varied from 20.65 to 27.54 t/ha. The volume of water applied ranged from 11,830.0 to 15,222.0 m3/ha for 2 to 4 years age of the crop. The average initial cost of drip system for grapes (Thompson Seedless) was found as Rs. 42,000 ($1354) and the net cash inflow for ten years as Rs. 12,39,311 ($39977).
Keywords: Drip/Trickle irrigation, Microirrigation, Grapes, Cost analysis
Abstract taken from paper found on pages 824 to 829 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Present Status of Microirrigation in Tamilnadu, India
M. V. Somasundaram, V. Duraisaminathan, N. V. Pundarikanthan
Tamilnadu, the southernmost state of Peninsular India, has already accounted for utilization of its surface water resources in 34 major irrigation schemes, 57 minor irrigation schemes and 40,000 tanks and groundwater resources from 1.75 million wells. 95% of the surface water resources have already been harnessed. At the time of independence in 1947 the groundwater reserves were 10 times that of annual rainfall. However at present in many places they are either equal to or less than that of annual rainfall. Population explosion and the advent of power driven pumpsets have resulted in rapidly declining water levels. Due to these conditions awareness is already there to conserve water and utilize microirrigation concepts.
Concepts and applications of microirrigation as advocated by various organizations such as Centre for Water Resources of Anna University, Tamilnadu Agricultural University, Agricultural Engineering Department, Department of Agriculture, nongovernmental organizations, promoters and vendors are described. The results indicate that drip irrigation is attaining popularity. But sprinkler irrigation is not popular due to high humidity, wind drift and poor uniformity coefficient. Microirrigation concepts were not utilized to the maximum extent possible due to such factors as lack of sufficient knowledge and training for farmers, lack of follow up maintenance by farmers and vendors, high initial expenses and small land holdings.
Keywords: Yield response, Areal coverage, Manufacturer's role, Government subsidy, Performance evaluation
Abstract taken from paper found on pages 830 to 834 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Apple Coloring and Yield Studies under Micro-sprinkler Systems
Kuiwen Zhang, Yongliang Dang, Fengqiang Miao
The preharvest one month and more is the period of fastest fruit growth and optimal fruit coloring. In order to improve the yield and quality of fruit, and to increase the economic benefits, it is important to determine the main technical points for apple growth under the "Dusk spraying" new methods. The "Dusk spraying" means spraying a little water over fruit trees at dusk (16:00-17:00) everyday.
The focal point of this paper concerns coloring and yield increase technique for Xiaoguoguang apple during the preharvest period under micro-sprinkler irrigation. The mechanism of coloring and yield increase technique for apple and the sensitive reaction to water is shown. By means of experimental contrast, the paper sets forth the optimum spraying time, spraying amount, atomization index, water content of soil and miscellaneous technical parameters. The experiment indicates that over trees "Dusk spraying" under micro-sprinkler systems was the best method compared with other different treatments for the increase of yields, percentage of first-class fruit, and percentage of double-red fruit (the concentration coloring surface of an apple > 70%). Remarkable economic benefits have been produced.
Keywords: fruit production, microirrigation
Abstract taken from paper found on pages 835 to 839 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Modelling the Soil Water Balance under Microirrigation
J. G Annandale and G. S. Campbell
The soil water balance under microirrigation is best described in three dimensions (3-D). A step by step derivation of a 3-D soil water flux model is presented. Required soil inputs are bulk density and at least two points on a moisture release curve. Three dimensional soil variability can be taken into account with this approach if the detailed soil data is available.
Keywords: Three-dimensional, Soil water balance, Matric flux potential, Microirrigation
Abstract taken from paper found on pages 840 to 850 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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A Simple Equation to Estimate Soil-water Movement from a Drip Irrigation Source
F. S. Zazueta, G. A. Clark, A. G. Smajstrla and M. Carrillo
This work describes a simple equation to estimate the diameter of the wetted-bulb resulting from infiltration into a dry, deep, uniform soil from a drip irrigation source. To develop the proposed equation the dimensional analysis technique was used. The equation compares well with other equations determined from analytical and regression models. Measurements of wetted bulb parameters for Florida soils were made to calibrate the equation.
Keywords: Infiltration, drip, microirrigation
Abstract taken from paper found on pages 851 to 856 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Distribution Characteristics of Microsprinklers
A. K. Pandey, H. S. Chauhan, K. K. Singh and K. N. Shukla
Single nozzle studies were conducted on five makes of microsprinklers of 1 mm to 2 mm sizes manufactured in India. The experiments were conducted at four pressures and four riser heights for the study of radius of throw, effective radius and distribution characteristics. Radius of throw was determined by BIS method, whereas effective radius and distribution characteristics were evaluated by Keller and Boman methods.
Keywords: Microirrigation, Microsprinkler
Abstract taken from paper found on pages 857 to 862 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Studies on Single Nozzle Performance of Microsprinklers
A. K. Pandey, H. S. Chauhan, K. N. Shukla and K. K. Singh
Performance parameters such as average application rate, effective maximum depth (Dxe), absolute maximum depth (Dxa) and coefficient of variation (CV) were determined by single nozzle test for five makes of commercially available microsprinklers designated for reference as A, B, C, D and E. The average application rate computed by Keller method was found to have lower values at lower pressures. The Boman method gave higher values of application rate as compared to Keller method at all riser heights and pressures for microsprinklers A, C and D.
The range of mean depth at varying pressures and heights for microsprinklers A, B, C, D and E respectively were found to be 6.0 to 2.0 mm, 6.0 to 4.0 mm, 16.0 to 5.0 mm, 3.0 to 2.0 mm and 9.0 to 2.0 mm respectively. The range of CV for microsprinklers A, B, C, D and E were found to be 254.0 to 76.0, 207.0 to 90.0, 189.0 to 66.0, 199.0 to 105.0 and 215.0 to 63.0 percent respectively.
Keywords: Microsprinkler, Microirrigation, Irrigation equipment, Testing
Abstract taken from paper found on pages 863 to 868 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Reducing Lateral Head Loss by Hemispherical Emitter Barb Protrusion
M. S. M. Amin
The connection of on-line point source outlets such as emitters and microsprinklers to laterals usually causes additional head loss. The presence of emitter barbs obstruct the flow in the otherwise smooth PE pipes. The head loss increases with increased turbulence caused by the barb shape and size, especially in the high Reynolds number flow regime at the upstream end of the lateral pipe. By reducing the head loss due to barb protrusion, longer or smaller size laterals can be laid in the field for a specified amount of allowable head loss. This paper reports work done to reduce the drag force on the barb protrusion. Several combinations of emitter barb shape and location of offtake were evaluated in a laboratory. The pressure compensating effect of upstream protrusion on orifice emitters was evaluated. An orifice immediately downstream of a hemispherical protrusion was found to be pressure compensating. Such an emitter requires low operating pressure, has turbulent flow regime, and a large opening. Head loss across the hemispherical protrusion was very low due to delayed separation.
Keywords: lateral headloss, emitter barb protrusion, microirrigation
Abstract taken from paper found on pages 869 to 874 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Clean Pressure drop and Loss Coefficients for Trickle Irrigation Screen Filters
D. S. Parwal, H. S. Chauhan and C. S. Jaiswal
A procedure was outlined by International Standards Organization (IS0) for determination of clean pressure drop for strainer type filters. Because of possible difficulties encountered in determining clean pressure drop, the item was postponed/deleted, considering it a subject of a future international standard.
The feasibility of the outlined procedure was practically determined for commercially available strainer filter of four makes, designated as A, B, D and E with discharge varying from 1.38 L/s to 8.33 L/s and mesh number 200, 160, 160 and 120 respectively. According to the procedure outlined, minimum and maximum discharges were found for all the four filters. Screen head losses and inlet pressures were also found corresponding to the five discharges for each filter.
The applicability of well screen theory of Peterson et al. (1953) to drip irrigation screen filters was explored. According to this theory loss coefficients were computed and found to have values 35 to 38, 1100 to 1330, 17 to 20 and 17 to 21 for the filters A, B, D and E respectively. The loss coefficients at nearly equal velocities of 0.20 m/s 0.18 m/s and 0.22 m/s were found to be 36.67, 20.43 and 17.22 and thus having a decreasing trend, for filters A, D and E having apertures of 200, 160, and 120 mesh respectively.
Keywords: Drip/Trickle irrigation, Irrigation equipment, Filters
Abstract taken from paper found on pages 875 to 880 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Hydraulic Response of Drip Irrigation Sand Filters
V. K. Sood and H. S. Chauhan
Commercially available drip irrigation media filters, one a 5X5 cm horizontal single medium filter and the other a 5X5 cm vertical multimedia filter, were studied for various sets of values of discharge versus clean water pressure drop. For the horizontal filter, the minimum and maximum discharges were found as 5.5 and 5.9 L/s, corresponding to an inlet pressure and max differential pressures of 200.0 kPa and 14.93 kPa, respectively. Similarly, for the vertical sand filter minimum and maximum discharges were found as 1.86 and 2.55 L/s corresponding to an inlet pressure of 300.0 kPa and a maximum differential pressure of 8.82 kPa respectively. The method used to determine head loss was found to be cumbersome. The maximum head losses estimated by the Kozeny-Carman relationship for the horizontal single medium and the vertical multimedia filters were 5.46 and 0.874 kPa as compared to the experimentally observed values 14.93 and 8.82 kPa, respectively.
Keywords: Sand filter, Drip/Trickle irrigation, Irrigation equipment, Microirrigation
Abstract taken from paper found on pages 881 to 886 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Treatment Requirements of Secondary Effluent for Microirrigation
David J. Hills and Massoud Tajrishy
Reluctance on the part of the engineering design community to apply wastewater effluent in microirrigation is due primarily to limited full-scale operating experience and the lack of rational criteria for design and operation of the system. Design criteria have not been developed because of very little information has been generated on the relationships between emitter performance and differing water qualities. The major disadvantage of microirrigation is the potential for clogging. Clogging of even a small percentage of emitters can severely affect the uniformity of water application.
Microirrigation researchers and equipment manufacturers have chosen two approaches for solving the clogging problem. The first is to improve emitter design by either developing self-cleaning emitters that require minimal water treatment (Hills and El-Ebaby, 1990) or by designing wide, turbulent-flow labyrinth passageways to reduce emitter clogging (Soil Conservation Service, 1984). A second approach, which is the subject of this research, is to focus attention on improving the quality of water before it reaches the emitter (Nakayama et al., 1978). However, the successful operation of long-term microirrigation systems requires that the interdependent effects of both water quality and emitter design be carefully considered before making water treatment recommendations.
Chlorine is a low cost disinfectant for secondary effluent used for irrigation of fodder, fiber, and seed crops, orchards, and vineyards. Ultraviolet disinfection is an alternate to chlorine treatment, especially if the effluent is to be used for fresh market crops. UV disinfection, following sand filtration, has been demonstrated to reliably produce a water quality that meets the most stringent current health standards (California State Department of Health Services, 1978). A combination of UV disinfection and chlorination (to provide a residual bactericide) may be necessary for producing water with an acceptable bacterial count for microirrigation of fresh market produce.
The objective of this investigation was to evaluate treatment criteria (filtration, chlorine injection, and ultraviolet light disinfection) for prevention of bio-fouling within a microirrigation system when using secondary wastewater effluent.
Keywords: Microirrigation, Reclaimed wastewater, Chlorination, Filtration
Abstract taken from paper found on pages 887 to 892 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Cabbage Growth Under Different Irrigation Methods
H. S. Chauhan and Prabhat Srivastava
The effect of microsprinkler, drip (emitter), drip (microtube) and surface methods of irrigation on growth characteristics of cabbage (Brassica oleracea) in the humid subtropical climate of Pantnagar (India) was investigated. The experiments were conducted on sandy loam soil with a bulk density of 1.46 g/cm3 and field capacity of 18.67 per cent by weight. The plants were spaced as 0.5X0.6 m in the four treatments each occupying an area of 60 m2. The crop canopy area was highest for microsprinkler followed by emitter, surface and microtubes method of irrigation. Crop canopy area was 7.59 and 2.04 per cent greater for microsprinkler and emitter irrigation over surface irrigation. Average number of leaves was highest for microsprinkler followed by emitter, surface and microtube irrigation. Average percentage increase in leaf area of cabbage was 7.20 and 1.69 per cent respectively for microsprinkler and emitter irrigation over surface irrigation. Average per cent increase in the size of head expressed as diameter of cabbage for microsprinkler and emitter irrigation was 6.98 and 2.15 per cent over surface irrigation.
Keywords: Cabbage, Microirrigation, Growth
Abstract taken from paper found on pages 893 to 898 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Effect of Microsprinkler and Other Irrigation Methods on Cabbage
Prabhat Srivastava and H. S. Chauhan
A comparative evaluation of microsprinkler, drip, microtube and surface irrigation was conducted to study their performance on cabbage (Golden Acre) grown at Pantnagar, India. The soil was sandy loam in texture with an average bulk density of 1.46 g/cm3 and average field capacity of 18.67 percent by weight. The experiments were conducted in an area of 240 m2 with each of the four treatments occupying an area of 60 m2 and having 171 plants. The spacing of plants were 0.5 m X 0.6 m.
The maximum yield was obtained with microsprinkler irrigation 40.23 t/ha, followed by emitters 38.97 t/ha, surface irrigation; 33.76 t/ha and microtubes 32.54 t/ha. The water use efficiency was found to be maximum for emitters 4.48 t/ha-cm, followed by 3.96 t/ha-cm for mictrotubes, 2.98 t/ha-cm for microsprinklers and 1.58 t/ha-cm for surface irrigation. The water saving in cause of microtube, emitter and microsprinklers were found to be 61.44, 59.28 and 36.82 percent respectively over surface irrigation.
Keywords: Cabbage, Drip Irrigation, Yield response, Water use efficiency
Abstract taken from paper found on pages 899 to 903 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Exploratory Studies on Microirrigation for Processing Tomatoes in Central Brazil
Washington L. C. Silva and Waldir A. Marouelli
The objective of this work is three-fold: 1) to introduce microirrigation into processing tomato crop in Central Brazil, 2) to adjust crop coefficient, and 3) to compare drip with microsprinkle irrigation. Treatments consisted of a combination of irrigation frequencies with ET crop multiplying factors. Yields over 90 tons/ha were obtained under drip irrigation while the average yield nationwide falls below 40 tons/ha. Crop yield increased considerably by increasing the amount of water applied, for daily irrigations. The highest commercial yield was associated with the lowest irrigation frequency (6 days). Among the driest treatments, the one irrigated daily yielded significantly better. Although soil matric potential varied from -20 kPa for the wetter treatments to -70 kPa for the drier ones, a general occurrence of fruits with blossom-end rot was observed in all treatments. When comparing irrigation methods it was noticed that first harvest yields were significantly smaller for microsprinkler treatments. Generally, higher soluble solids content was associated with drier or lower frequency irrigation. Overall, it can be concluded that it is feasible to irrigate processing tomatoes using microirrigation methods, especially drip systems. Further work, however, is needed mainly on the economics and on the application of fertilizers through irrigation water.
Keywords: Microirrigation, Drip, Microsprinkle, Tomato
Abstract taken from paper found on pages 904 to 908 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Response of Brinjal (Solanum Melongena L.) under Microsprinkler and Other Methods of Irrigation
K. L. Singh, H. S. Chauhan, K. K. Singh and Sewa Ram
Field experiments were conducted in area of 640 m2 from February to June 1992 at G. B. Pant University of Agriculture and Technology, Pantnagar to study the performance of microsprinkler, drip (microtube), drip (emitter) and surface method of irrigation on brinjal crop (Solanum melongena L.) cultivar Pant Samrat. The site is located at 243.8 m altitude 29° N latitude and 79.3° E longitude, in humid subtropical climate and a sandy loam soil in India. The study indicated that the highest yield was obtained for the plots irrigated with microsprinkler (29.33 t/ha) followed by microtube (28.74), emitters (26.40) and surface method (24.26 t/ha). The percentage increase in yield over surface irrigated plot was 15.6, 8.1 and 17.28 for microtube, emitter and microsprinkler irrigated plots respectively. The total depth of water applied including effective rainfall of 9.58 cm for surface irrigation, microsprinkler, microtube and emitter was 85.54, 57.2, 47.58 and 44.24 cm respectively. The percentage saving of water over surface irrigation treatment was 48.28, 44.37 and 33.13 for emitter, microtube and microsprinkler irrigation respectively.
Keywords: Brinjal, Microsprinkler, Drip/Trickle Irrigation
Abstract taken from paper found on pages 909 to 912 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Field Studies of Drip and Other Methods of Irrigation on Various Growth Aspects of Tomato
P. Koteswara Rao, Raj Vir Singh, H. S. Chauhan, K. N. Shukla
Field studies of drip and check basin methods of irrigation were undertaken to evaluate various growth parameters of a tomato crop in the Nanital Tarai region of India. Crop response was evaluated on the basis of plant height, number of branches and leaf area. The maximum values of plant height, number of branches and leaf area were found for microtube drip irrigation followed by single pairwise, double pairwise and check basin methods of irrigation. The percentage increase in plant height, number of branches and leaf area over check basin irrigation was found to be maximum for the microtube system of drip irrigation.
Keywords: Drip irrigation, Growth, Tomato, Microirrigation
Abstract taken from paper found on pages 913 to 918 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Field Studies on Drip and Other Methods of Irrigation on Yields and Water Use of Tomato
P. Koteswara Rao, Raj Vir Singh, H. S. Chauhan
Field studies were conducted to determine yield and water use of tomato crop in drip and check basin methods of irrigation under climatic conditions of the Nainital Tarai region of India. The percentage increase of yield for drip-irrigated tomato over surface-irrigated tomato were 25.33, 18.37 and 26.26 percent for single pairwise, double pairwise and microtube irrigation, respectively. The percentage savings of water over surface irrigation were found to be 33.90, 39.74 and 43.12 for double pairwise, single pairwise and microtube drip irrigated tomato, respectively. They yield and saving of water were found to be maximum for microtube system of drip irrigation.
Keywords: Drip irrigation, Microirrigation, Yield, Water use, Tomato
Abstract taken from paper found on pages 919 to 922 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Subsurface Drip Irrigation to Evaluate Transpiration Ratios of Pearl Millet
W. A. Payne, B. Gérard, and M. C. Klaij
A subsurface drip irrigation system was evaluated in a sandy soil of Niger for measuring transpiration ratios (dry matter/transpiration) of two pearl millet varieties grown under contrasting levels of water and nutrient availability. Water was applied using double-chamber drip irrigation lines installed sufficiently deep (0.25 m) to assume that soil evaporation was negligible. Transpiration was determined from neutron probe data and drainage calculations based on two soil hydraulic conductivity curves. Consistent with pot studies, transpiration ratios decreased with nutrient stress, and increased with water stress. The local landrace had a larger transpiration ratio than the variety GB-8735. At high fertility levels, transpiration ratios ranged from 3.77 g kPa kg-1 for GB-8735 in the high irrigation treatment, to 8.76 g kPa kg-1 for the local landrace in the low irrigation treatment. These agree well with published data. Some of the calculated transpiration ratios seemed unrealistically small in the low fertility treatment, but they permitted an estimation of about 1 g kPa kg-1 as the lower limit of detection of the method. The system permits a reliable method of comparing transpiration ratios so long as growth conditions are favorable enough to reach this lower limit.
Keywords: Pearl millet, transpiration, WUE, subsurface drip irrigation
Abstract taken from paper found on pages 923 to 931 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Microcomputer Programs for Irrigation Management: CitRie-PC
J. de Zayas-Díaz, E. Toledo and N. Oceguera
CitRie-PC is a microcomputer software package for controlling, evaluating and forecasting irrigation. Its different modules make possible to calculate through simulations models, moisture performance in drip or microjet irrigated groves as well as keeping historical moisture records. The printouts showing field moisture performance by gravimetry, neutron probe and water balance, both for individual pumping units and a group of them may be either through tables or graphics.
Keywords: Irrigation, Computer model, Microirrigation
Abstract taken from paper found on pages 932 to 936 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Drip Irrigation Technology as a Powerful Tool to Protect our Environment
Uri Or
There are today various fields in which drip irrigation technology is contributing towards environmental protection, a subject of increasing interest in Israel.
Much knowledge and experience in drip irrigation have been acquired in the following areas:
1. Use of Sewage Effluent An increasing percentage of the sewage water produced in Israel is reused for the irrigation of agricultural crops. New filtration systems and water treatment methods have been developed and applied. Above-ground and underground drip irrigation systems were built, which enable the use of sewage effluent.
2. Accurate Irrigation A great deal of attention is given to irrigation management, and control of irrigation and fertigation, according to plant requirements. Irrigation is carried out during the day in drips and pulses, so that there is almost complete prevention of water leaking from the root zone of the plants to the water table.
3. Prevention of the Spread of Plant Diseases Accurate drip irrigation prevents run-off and flow of water in the drainage canals, thus preventing the spread of plant diseases and weeds.
4. Saline Water for Irrigation The pulse drip irrigation method creates a static situation in which the salt concentration of the soil solution is stable, permitting the use of saline water for irrigation purposes and quality water for drinking.
5. Soilless Cultivation A drip irrigation system for soilless cultivation has been developed, by reusing retained water, producing high yields on a given area.
Drip irrigation can be a very powerful tool for improving environmental protection.
Keywords: Drip Irrigation, Environmental Protection, Wastewater, Accurate Irrigation
Abstract taken from paper found on pages 937 to 943 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Economic Analysis of Microirrigation Systems Considering Field Shape Parameters
D. T Shete, D. B. Raut, P. M. Modi
A study was conducted to determine the effects of field shape parameters (i.e. rectangular fields) on the design of drip irrigation systems and to determine the effects of area to perimeter ratio (A/P) on capital cost, operating cost and net return for rectangular fields. A banana plantation was irrigated using a drip irrigation system. Seven different field sizes; 100 m * 200 m, 125 m * 250 m, 150 m * 300 m, 175 m * 350 m, 200 m * 400 m, 225 m * 450 m and 250 m * 500 m were studied. It was found that for ratio of shorter dimension of the field to longer dimension of the field (L1/L2) = 0.5, A/P has direct bearing on the capital cost, operating cost and the net return.
Keywords: geometry, drip irrigation, costs, investments
Abstract taken from paper found on pages 944 to 948 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Drip Irrigation with Agrowells for Vegetable Production in Sri Lanka
C. S. De Silva
The overall objective of this research paper is to understand the use of drip irrigation system to irrigate from large diameter wells (Agrowells) in the hard rock aquifer for the sustainable development in the dry zone of Sri Lanka. Observation bore holes were installed in the study site on different radial distances from the well down to the well depth. Rainguages and a Class A Evaporation pan were installed to measure the daily rainfall and evaporation. Several pumping tests were conducted and the daily water levels in the observation bore holes, wells and the volume extracted from the wells with pumping duration were recorded. Annual recharge was calculated by the soil moisture balance method for the hydraulic year and the groundwater resources were estimated. Results showed that the recovery patterns of the Agrowells in the hard rock aquifer is very slow due to the low transmissivity. Ninety percentage of the total annual recharge occurred during the wet season and the irrigation took place during the dry season to supplement the rainfall. Severe limitations should be imposed on pumping rates and duration with the traditional irrigation system to avoid over exploitation of the aquifer. Results also showed that only 1-2 ha of vegetable crops could be cultivated with the traditional irrigation systems and farmers tend to irrigate double the amount of crop water requirement. Excess water is lost due to evaporation and surface runoff. Most of the wells were dry by mid season and the yield was reduced due to water stress. Drip irrigation is preferred to the other traditional irrigation systems because of the higher water use efficiency. Results indicated that the cultivable extent could be doubled with drip irrigation and irrigating vegetable crops throughout the year without drying the well in the mid season.
Keywords: Extraction, Agrowell, water use efficiency
Abstract taken from paper found on pages 949 to 954 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Minimizing Nitrate Leaching in Citrus Orchards with Low Volume Irrigation
Dariusz Swietlik
Recovery of fertilizer N in the form of nitrates in the top 3 m of soil was studied in a young grapefruit orchard cv. 'Ray Ruby' four years after different nitrogen rates and irrigation treatments were initiated. The irrigation treatments were: 1) trickle irrigation based on estimated evapotranspiration calculated as 0.7 (first 3 years) and 0.5 (4th season) of Class A pan evaporation (TPAN), 2) trickle irrigation based on an average tensiometer reading of - 0.02 MPa at 30 cm depth (TTEN), and 3) flood irrigation (FLOOD) with 15 cm of water whenever neutron probe readings indicated 50% available soil water depletion at 30 cm (first 3 years) or at 30 and 60 cm (4th year). N0 (no nitrogen), N1 (20, 40, 80, 160 g n/tree/year in the 4 consecutive years) and N2 (twice the N1 levels) treatments were superimposed on trickle and flood irrigation. Nitrogen was injected into the trickle lines or, under flood, applied beneath the trees. The net amount of fertilizer N recovered was highest in the TTEN treatment followed by the TPAN and FLOOD treatments which produced similar values. However, because of a smaller surface area treated, the fertilizer was more concentrated under trickle than flood irrigation at equal N rates per tree. TTEN treatment produced 45% recovery of fertilizer N which was 4 times higher than under the FLOOD and TPAN treatments. The amount of irrigation water calculated on a per wetted surface area basis in TTEN treatment constituted only 40% of the amount used in the FLOOD and TTEN plots indicating the decreased leaching potential in TTEN. The reduction in NO3 leaching in TTEN was accomplished by reducing water amounts but without sacrificing the trees' growth and yield which was similar between all irrigation treatments. Increased denitrification most likely contributed to the increased soil N losses under the TPAN and FLOOD plots due to periodic excessive water in the soil.
Keywords: Trickle irrigation, Flood irrigation, Grapefruit, Yield, Vegetative growth
Abstract taken from paper found on pages 955 to 960 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Yield, Growth and Nitrate Leaching in Drip-irrigated Citrus Trees Under Different Fertigation Treatments
J. R. Castel, A. L. Lidón, C. Ginestar, C. Ramos
A field experiment was conducted in a 2 ha plot with Clementina de Nules citrus trees planted in 1985. Four irrigation amounts (50, 80, 110 and 140% of ETlys) and two nitrogen rates (N1 = 120 and N2 = 210 Kg N ha-1 yr-1) were applied during the 1992 and 1993 seasons, through a drip irrigation system with four emitters per tree. The experimental design was a factorial (4x2) of complete randomized blocks with three replicates of 30-36 trees each. Maximum tree evapotranspiration (ETlys) was determined daily in a large weighing lysimeter installed in the same plot. Irrigation frequency was the same for all treatments. Nitrogen was applied as N-20 solution in weekly applications from April to September.
In four of the treatments (N1-50% ET; N1-140% ET; N2-50% ET and N2-140% ET), deep percolation and nitrate leaching in the wetted zone were estimated by chloride balance and nitrate concentration in the soil solution at 45-60 cm depth.
The amount of nitrogen applied did not affect significantly tree growth and yield. However, irrigation at 50 and 80% ET was insufficient, reducing growth of the trunk. Yield in the lower irrigation treatments (50% ET) was also decreased compared to the 140% ET due to a reduction in the average fruit weight.
On a seasonal basis, N leaching losses ranged from about 208 kg N ha-1 for the high irrigation and high N treatment to about 56 kg N ha-1 for the low irrigation and low N treatment, with similar effects of the nitrogen and irrigation treatments in determining these losses.
Keywords: Citrus, drip, nitrate leaching
Abstract taken from paper found on pages 961 to 968 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Watermark Moisture Sensors--Use with ET Based Scheduling Models
William R. Pogue, James L. Kline
The use of weather based irrigation scheduling models has been refined over the past decade, but this technique has not been widely adopted in production agriculture. One of the problems associated with this technique is the fact that inherent errors exist in the model, and they propagate over time. In microirrigation, scheduling errors can be more costly, since this irrigation method requires soil water status to be maintained within a fairly narrow window at the wet end of the soil water range. Most research into ET Scheduling Models has demonstrated the need for reliable, on site measurements of soil water status as a means to frequently re-initialize the ET Model. This paper examines a new sensor technology, WATERMARK, which can be easily interfaced with electronic data-logging systems, and how it can be used as a source of soil moisture data needed for refining ET based scheduling models in microirrigation systems.
Keywords: Irrigation Scheduling, Modeling, Soil Moisture, Tensiometers, Microirrigation, Expert Systems
Abstract taken from paper found on pages 969 to 974 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
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Tree-clip Development in Microirrigation Allows Easy Frost and Freeze Protection
Susan S. Thayer
A destructive freeze struck the citrus groves of central and north Florida hard in 1989 resulting in great losses--and a great advancement in modern frost protection for citrus groves, orchards and other commercial tree operations. The Maxijet Tree Clip, which is clipped permanently into the limbs of the tree and attached by vinyl tubing to a ground-level stake assembly, provides frost and freeze protection with the simple turn of a valve at the start of winter. The Tree Clip provides simplicity, reliability and durability while it has proven itself to save time, money, water and trees with application in a wide variety of agricultural operations.
Keywords: Microirrigation, Frost protection, Freeze, Microsprinkler, Misting
Abstract taken from paper found on pages 975 to 978 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
