Subsurface Drip Irrigation Publications
Although subsurface drip irrigation on alfalfa is used in a number of areas in the arid west, little information on the use of this irrigation system for alfalfa is available in the scientific literature. This page provides some of the popular publications available on this topic.
By Abdel Berrada
Summary: In this context, a field experiment was conducted in 2002 and 2003 to investigate the effect of water stress on alfalfa Dry Matter (DM) yield and hay quality. Three water stress levels were imposed on three alfalfa cultivars with contrasting dormancy rating, in a split-block design. The irrigation system used was subsurface drip irrigation (SDI) with 60-in. lateral spacing and 18-in. placement depth. Total alfalfa DM production (adjusted to 12% moisture) averaged 5.7 t/a in 2002 and 5.3 t/a in 2003, with no significant differences among cultivars. Alfalfa DM production increased significantly with increasing amounts of irrigation. A hailstorm on September 9, 2003 reduced alfalfa yield at the third cut, particularly in the least- and moderately stressed water treatments. Alfalfa protein concentration averaged 21% in 2002 and 2003, with no significant differences among cultivars or irrigation treatments. Alfalfa relative feed value (RFV) was highest in the most stressed treatment and lowest in the least stressed treatment. Alfalfa water use efficiency averaged 395 to 467 lb of DM per inch of water in 2003. It took 4.5 inches of water to produce one ton of alfalfa hay in the least stressed treatment and 5.1 inches in the most stressed one. More water, 5.3 to 6.1 inches, would have been required to produce one ton of hay with the predominant irrigation system in the Full Service Area of the Dolores Project. Visual observations suggest that 40-in. lateral spacing would be suitable for alfalfa hay production with SDI. Research is needed to determine the optimum drip tape lateral spacing and placement depth for alfalfa and other crops grown in southwestern Colorado. Initial cost, maintenance, and gopher control are among the challenges that could hamper the use of SDI for field crop production in southwestern Colorado.
By F. R. Lamm, K. R. Harmoney, A. A. Aboukheira, and S. K. Johnson
Summary: A three-year yield study was conducted at the Kansas State University Northwest Research-Extension Center in Colby, Kansas, to evaluate production of subsurface drip irrigated alfalfa on a deep productive silt loam soil. Three irrigation levels (randomized complete block design of three replications) designed to replace 70%, 85%, or 100% of the calculated crop evapotranspiration minus precipitation were compared in terms of alfalfa yield, irrigation amount, plant-available soil water, crop water use, and crop water productivity. Alfalfa yield was also evaluated at three perpendicular horizontal distances from the 1.5 m spaced driplines (0, 0.38, and 0.76 m). Annual alfalfa yields were unaffected by irrigation level, averaging 20.8 Mg ha-1 while irrigation amounts averaged 396, 484, and 586 mm for the 70%, 80%, and 100% ET irrigation levels, respectively. Seasonal crop water use was significantly greater with increased irrigation, but only by an average difference of 137 mm among irrigation levels as compared to the 190 mm difference in irrigation amount. Crop water productivity was significantly greater with decreased levels of irrigation, with values of 23.5, 22.0, and 20.4 kg ha-1 mm-1 for the 70%, 85%, and 100% ET irrigation levels, respectively. No significant differences existed in alfalfa yield with respect to horizontal perpendicular distance from the dripline with the exception of the 0.76 m distance, which yielded less in the drier and warmer year 2006. Large and significant decreases in alfalfa yield and crop water productivity occurred with successive harvests, with the first harvest having 272% and 196% of the fifth harvest yield and crop water productivity, respectively. Plant-available soil water decreased as the season progressed for all irrigation levels, but to a much greater extent for the 70% ET level, averaging at the time of the fifth seasonal harvest only 41% and 54% of the soil water for the 85% and 100% ET irrigation levels, respectively. These large seasonal decreases in soil water for the 70% ET irrigation level would be anticipated to be of even greater concern in extended multiple-year drought periods. This fact coupled with the 102 mm reduction in seasonal irrigation amount for the 85% ET irrigation level compared to the 100% ET irrigation level leads to a recommendation of scheduling replacement of 85% of the ET minus precipitation when subsurface drip irrigating alfalfa in the Central Great Plains.
By Mohammed H. Almarshadi and Saleh M. Ismail
Summary: A field experiment comparing different irrigation methods (Sprinkler Irrigation “SPI”, surface drip “DI” and sub-surface drip “SDI) were precisely controlled for alfalfa productivity and water use efficiency. The experiment was conducted at the Agricultural Experimental Station of King Abdel-Aziz University. The design of the experiment was Randomized Complete Block Design (RCBD) with four replicates, consists of three irrigation method. Water Electronics Module (WEM) technology was used to fully controlled the irrigation methods. The results revealed SDI increase growth parameters (plant length, number of tillers and leave to stem ratio) compared with DI and SPI. The least water supply was recorded in SDI followed by DI and SPI respectively while the highest IWUE obtained from SDI followed by DI and the least IWUE was recorded in SPI. SDI and DI saved 35.7% and 29.2% of irrigation water compared with SPI. In spite of decreasing water supply under SDI and DI high dry yield was obtained. The increase in dry yield was 45% in SDI and 15.9% in DI compared with SPI. The results of experiment especially soil moisture data proved that WEM is a practical tool to precisely supplied irrigation water when needed and can be recommended for efficiently controlled different automated irrigation systems.
By Freddie R. Lamm, Keith R. Harmoney, Abdrabbo A. Aboukheira, and Sandy K. Johnson
Summary: A field study was conducted from 2005 through 2007 at the KSU Northwest Research-Extension Center, Colby, Kansas to examine alfalfa production at three perpendicular distances from the dripline (0, 15 and 30 inches) for 60-inch spaced driplines under three irrigation regimes (treatments designed to replace 100, 85 or 70% of ETc minus precipitation). No statistically significant differences in dry matter yields were attributable to irrigation level, but a tendency for slightly reduced yields was observed with less irrigation as the season progressed through the 4 to 5 harvests annually. Also, yields tended to decrease with distance from the dripline during a dry season.
By Saleh M. Ismail and Mohammed Hussien Almarshadi
Summary: A field experiment studying the effect of water stress on alfalfa (Medicago sativa) productivity and water use efficiency was conducted at the Agricultural Experimental Station of King Abdelaziz University. The design of the experiment was randomized complete block design (RCBD) with four replicates. It consisted of three treatments, namely: field capacity treatment (FC) as a control, 85% FC and 70% FC as stress treatments. The irrigation water for all treatments was precisely supplied using recent technology known as the water electronics module (WEM). Results indicated that decreasing water supply decreased fresh and dry yield of alfalfa but increased irrigation water use efficiency (IWUE). As a result, 13 and 27% of irrigation water were saved from 85% FC and 70% FC treatments respectively in each cut compared with the FC treatment. The reduction of water supply resulted in a yield reduction of 12 and 21.7% for 85% FC and 70% FC, respectively. The results also proved that WEM is a practical tool to precisely supply irrigation water and can be used effectively to control deficit irrigation.
By Don Breazeale, Jerry Neufeld, Gordon Myer, and Jay Davison
Summary: This study found that producers would have to increase per acre yield by almost one and one-half tons to break even using SDI compared to flood irrigation. Continued research is required to determine if water savings and yield increases are possible using SDI in alfalfa production.
By K. C. Stone, P. G. Hunt, J. A. Millen, M. H. Johnson, T. A. Matheny, M. B. Vanotti, and J. C. Burns
Summary: The overall study objective was to determine the feasibility of using subsurface drip irrigation (SDI) for treated wastewater effluent applications. The specific objectives for the SDI system were to compare bermudagrass hay production using (1) commercial and wastewater effluent for nutrients, (2) two SDI lateral spacings (0.6 and 1.2 m) installed at 0.3 m below the surface, and (3) two irrigation application rates based on calculated evapotranspiration (ETc) requirements (75% or 100%). The two-year study measured hay yields, hay biomass, soil nutrients, and soil water nutrients. The SDI system was successfully operated for two years applying effluent and commercial fertilizer to supply the nutrient requirements of the bermudagrass hay. Bermudagrass hay production for 2004 and 2005 ranged from 5.65 to 14 Mg ha-1. Results from the SDI system indicated no significant differences between the SDI lateral spacings or irrigation application rates. Treatments using wastewater effluent had significantly higher hay yields and significantly higher nutrient biomass removal rates than the commercial fertilizer treatments. Nitrate-N observed in soil water lysimeters increased with depth, indicating the potential for leaching without proper management. Soil nitrogen and carbon were not significantly different for any of the treatments but did vary slightly over the life of the project.
Keith R. Harmoney, Freddie R. Lamm, Sandy K. Johnson, and Abdrabbo A. Aboukheira
Summary: The effects of a subsurface drip irrigation system at three levels of water inputs [70, 85, and 100% of plant evapotranspiration rates (ETr)] was investigated on resulting alfalfa production and nutritive value. Alfalfa was harvested at 0, 15, and 30 inches from established subsurface driplines within each of the three irrigation levels. Crude protein concentration and in situ dry matter disappearance, when found to be different at ETr and dripline distance combinations, tended to be greater at greater distances from the dripline and at the 70% ETr level. Fiber concentrations tended to be lower at greater distances from the dripline and at the 70% ETr level. Alfalfa yield was similar at all dripline distances and at all ETr levels in 2005 and 2007, but alfalfa yield was greater 0 inches from the dripline compared to 30 inches from the dripline in 2006. We conclude that alfalfa can be irrigated with subsurface drip systems at 70 or 85% ETr without sacrificing yield or forage nutritive value.
By Eric P. Eldredge, Clinton C. Shock, and Lamont D. Saunders
Summary: The purpose of this trial is to compare the productivity and hay quality of alfalfa varieties in the TreasureValley area of Malheur County. The trial also provides information about the adaptation of alfalfa hay production to drip irrigation. In thistrial, over 5 years, 10 proprietary varieties are being compared to 2 publiccheck varieties. This trial was established with a portable sprinkler-irrigation system and then grown with asubsurface drip-irrigation system.
By Mahbub Alam, Danny H. Rogers, and Troy J. Dumler
Summary: Subsurface drip irrigation (SDI) has the potential to effect increased yields in alfalfa with reduced water use and to reduce the effects of poor water quality. SDI also has some other benefits: Unlike with sprinkler and surface irrigation, SDI does not wet the soil surface. This property of SDI can reduce the growth of annual weeds. It can also allow simultaneous irrigating and harvesting, which means the soil can be kept moist even as bales dry in the field. Unfortunately, SDI is not without issues. Using SDI requires evaluating cost-effective dripline spacing and placement depth. For example, closer dripline spacing can reduce striping in the field, increase yield, and improve forage quality, but closer spacing also require more drip tape, which can become expensive. Root intrusion and rodent damage are also concerns with SDI in alfalfa.
By R.B. Hutmacher, C.J. Phene, R.M. Mead, P. Shouse, D. Clark, S.S. Vail, R. Swain, M.S. Peters, C.A. Hawk, D. Kershaw, T. Donovan, J. Jobes, and J. Fargerlund
Summary: A subsurface drip irrigation and furrow irrigation study was installed in a silty clay loam soil at the USDA-ARS Irrigated Desert Research Station near Brawley, CA in early 1991 to evaluate the potential for water savings and yield improvements with subsurface drip irrigation of forage alfalfa as compared to furrow irrigation. In bed-planted alfalfa, subsurface drip lateral spacings of 1.02 m (40 inch) and 2.04 m (80 inch) installed at an average depth of 40 cm below bed centers were investigated beginning in 1991. During the first one and one-half year operation, approximately 20 percent higher yields were achieved in the drip plots with 94 percent of the water application amounts used in the furrow irrigated plots. Problems with surface soil wetting were noted in all drip treatments during the 1991-1992 phases (Phase I) of the experiment. These problems resulted in the decision to reduce water applications during a "drydown" period during each harvest cycle to allow for harvest equipment traffic while limiting potential for soil compaction and plant damage from equipment. To provide an alternative method to deal with the surface soil wetting, the alfalfa crop was terminated in late 1992, the drip system replaced at 63 to 70 cm (25 to 28 inch) depth, alfalfa replanted in 1993, and the system operated in subsequent years. During this second phase (Phase II), applied water and evapotranspiration were similar (within 5 percent) in drip and furrow irrigated plots, while yields averaged between 19 and 35 percent higher in subsurface drip irrigated plots during the 1993 through 1996 period. Problems with surface soil wet areas were nearly eliminated with the deeper drip lateral placement during the 1993 through 1996 period. Additional work was conducted to determine long-term impacts of long-term drip system operation on patterns of salt accumulation using Colorado River water.
By Mahbub Alam, Todd P. Trooien, Troy J. Dumler, and Danny H. Rogers
Summary: A test of the suitability of subsurface drip irrigation (SDI) for alfalfa (Medicago sativa L) compared to a sprinkler, was conducted on a Kansas producer’s field where the soil is loam. The treatments included drip tape spacing of 60, 40, and 30 inches placed at depths of 18 and 12 inches. A nearby plot irrigated by a center pivot sprinkler was seeded to alfalfa and used for comparison. Seedling emergence and yield were adversely affected at 60 inch spacing, while the depth of placement of drip tapes (18 and 12 inches) showed no effect on yield. The site served for education and allowed comparison between SDI tape spacing and center pivot system.
By Shija Kazumba, Leonid Gillerman, Yoel DeMalach, and Gideon Oron
Summary: In this study, field experiments were conducted for two years on the commercial farm of Revivim and Mashabay-Sade farm (RMF) southeast of the City of Beer-Sheva, Israel. The purpose was to examine the response of alfalfa (Medicago sativa) as a perennial model crop to secondary domestic effluent application by means of a SDI system as compared with conventional overhead sprinkler irrigation. Emitters were installed at different depths and spacing. Similar amounts of effluent were applied to all plots during the experimental period. The results indicated that in all SDI treatments, the alfalfa yields were 11% to 25% higher than the ones obtained under sprinkler irrigated plots, besides the one in which the drip laterals were 200cm apart. The average Water Use Efficiency (WUE) was better in all SDI treatments in comparison with the sprinkler irrigated plots. An economic assessment reveals the dependence of the net profit on the emitters’ installation geometry, combined with the return for alfalfa in the market.
By Mahbub Alam, Todd Trooien, Steven Stone, and Danny Rogers
Summary: The results of two year field study on suitabilty of using SDI for alfalfa provided some answers to alfalfa producers of Kansas. The study was set-up in a producer field for demonstaration. The soil belongs to Otero-Ulysses complex and sandy loam in texture. The treatments included placement of drip tapes at (a) 1.5 m spacing at 0.46 and o.3 , depth of placement, (b) 1 m spacing at 0.46 and 0.3 m depth, (c) 0.76 m spacing at 0.46 depth, and (d) a center pivote sprinkler irrigated plot seeded to alfalfa. Emergence of seeding was advesrerely affectedat 1.5 m spacing of drip tapes showing “striping”. The total yield was reduced for spacing of drip tapes at 1.5 m in both 1999 and 2000. The depth of placement of drip tapes (0.46 and 0.3 m) showed no effect on yields.
By Drew W. Johnson and George F. Vance
Summary: Subsurface drip irrigation has many advantages for agriculture and the environment. However, many theoretical and design problems related to the application of SDI need further study. For example, how do we quantitatively describe the interrelationships among soil, water and plant? This research project addresses these concerns and provides answers to questions related to irrigation techniques and water-use efficiency. Initial objectives of the research were to: 1) Compare traditional flood irrigation with an innovative SDI method in alfalfa; 2) Develop BMP for SDI to optimize crop productivity and profits, maximize water-use efficiency, and minimize groundwater contamination.
By Maziar M. Kandelous, Tamir Kamai, Jasper A. Vrugt, Jiri Simunek, Blaine Hanson, and Jan W. Hopmans
Summary: A conceptual framework is introduced to assist in the design and management of subsurface drip irrigation systems for alfalfa that maximize yield, while minimizing deep percolation water losses to groundwater. Our approach combines the strengths of numerical modeling using HYDRUS-2D with nonlinear optimization using AMALGAM and Pareto front analysis. The HYDRUS-2D model is used to simulate spatial and temporal distributions of soil moisture content, root water uptake, and deep drainage in response to drip-line installation depth and distance, emitter discharge, irrigation duration and frequency. This model is coupled with the AMALGAM optimization algorithm to explore tradeoffs between water application, irrigation system parameters, and crop transpiration (Ta), to evaluate best management practices for subsurface drip irrigation systems in alfalfa. Through analysis of various examples, we provide a framework that seeks optimal design and management practices for different root distribution and soil textures.