Effect Of Subsurface Drip Irrigation Research Articles

Soil chemical characteristics, yield and technological quality of sugarcane under subsurface drip irrigation with treated sewage effluent

ABSTRACT Sugarcane cultivation requires sustainable strategies to meet water and nutritional needs. This study tested the hypothesis that irrigation with treated sewage effluent (TSE) can meet the water needs of sugarcane plants, improving their technological quality and yield. The objective of this study was to assess the effects of subsurface drip irrigation (SDI) with TSE or surface reservoir water (SRW) on soil chemical characteristics and technological quality and productivity. Thus, an SDI system was installed at soil depths of 0.20 and 0.40 m to apply SRW and TSE to sugarcane plants, composing four irrigation treatments (TSE0.2 m, TSE0.4 m, SRW0.2 m and SRW0.4 m) and a control (non-irrigated treatment). Analyses of soil chemical characteristics in different layers showed no negative effects for the use of SDI, which maintained favorable soil conditions for sugarcane plantations. The surface layer (0–0.2 m) irrigated with SRW or TSE showed higher accumulation of nutrients and organic matter. The results confirmed the hypothesis that irrigation with TSE or SRW improves the technological quality and yield of sugarcane; the treatment TSE0.2 m showed the best results regarding increases in sugar yield and alcohol production. However, continuous monitoring of soil salinity is necessary in wastewater-irrigated agricultural systems.

Effects of Subsurface Drip Irrigation on Water Consumption and Yields of Alfalfa under Different Water and Fertilizer Conditions

A field experiment was conducted for the purpose of examining the effects of different combinations of water and fertilizer applications on the water consumption and yields of alfalfa under subsurface drip irrigation (SDI). The results showed that the jointing and branching stages were the key stages for alfalfa water requirement. The water consumption had varied greatly (from 130 to 170 mm) during the growth period of each alfalfa crop. The water consumption during the whole growth period was approximately 500 mm, and the maximum water consumption intensity was 3.64 mm·d-1. The overall changes in water consumption and yields during the growth period of the alfalfa displayed trends of first increasing and then decreasing. The sensitivities of the yields to water changes were much higher than that of fertilizer. The water use efficiency (WUE) of the alfalfa was determined to range from 1.68 to 3.20 kg·m-3, and the rate of growth had ranged from 4.85% to 51.77%. The WUE and rate of growth of the alfalfa indicated the following trend: second crop > third crop > first crop. The results of frequency analysis based on the water‐nitrogen‐yield regression equation are the following: irrigation amounts of 142~165 mm and nitrogen application of 61~80 kg·hm-2 have a 95% probability of obtaining a hay yield of alfalfa of more than 11903 kg·hm-2. These results suggest that SDI is a promising irrigation method, which can increase the WUE and hay yield of alfalfa under the condition of SDI within an appropriate amount of water and nitrogen fertilizer, and too low or too high water and nitrogen fertilizer will adversely affect the WUE and hay yield of alfalfa.

Effect of subsurface drip irrigation-fertigation regimes on high density cotton cultivation in sodic soil

A field experiment was conducted to study the effect of subsurface drip irrigation- fertigation regimes on high density cotton cultivation under sodic soil at Anbil Dharmalingam Agricultural College and Research Institute, Tiruchirapalli during kharif 2019-20. The experiment was laid out in factorial randomized block design with three replications. The treatments consisted of combination of two factors viz., four subsurface drip irrigation levels (I1 – 0.4 Epan, I2 – 0.6 Epan, I3 – 0.8 Epan and I4– 1.0 Epan) and three fertigation levels (N1 – 100% RDF, N2 – 125%, RDF and N3– 150% RDF). Readings taken at the harvest stage revealed that the plant height, leaf area index, dry matter production and seed cotton yield were recorded significantly higher with subsurface drip irrigation level of 1.0 Epan. Among fertigation levels 150% RDF significantly recorded higher plant height, leaf area index and dry matter production but the total number of bolls plant-1, bolls m-2 and seed cotton yield were significantly higher with the fertigation of 125% RDF. The study shows that for better productivity of cotton in this region, subsurface drip irrigation of 1.0 Epan combined with fertigation of 125% RDF may be recommended for compact cotton varieties.

Effects of subsurface drip irrigation on alfalfa (Medicago sativa L.) growth and soil microbial community structures in arid and semi-arid areas of northern China

Water shortage is a common environmental stressor encountered by agricultural production in arid and semiarid areas of the world. Under this situation, the impacts of different irrigation methods on the forage yield, select soil physiochemical properties, and soil microbial community structures were identified after alfalfa was planted for three years in Ningxia, northern China. The experiment consisted of five irrigation methods/treatments with three replicates for each treatment, including flood irrigation (FL), sprinkler irrigation (SP), and three subsurface drip irrigation systems, with drip tapes buried at a depth of 10 cm (SSL), 20 cm (SSM) and 30 cm (SSD). The results showed that all water-conserving irrigation methods increased the soil water content compared with FL, but only SSM and SSD presented higher potential in increasing alfalfa yield by improving soil water content, pH value and available P. Moreover, compared with FL, SSM and SSD also presented greater effects in altering microbial community structures, such as the α-diversity, β-diversity, and bacterial composition at the order level, but did not significantly affect microbial taxon composition at the phylum level. Among all determined parameters, alfalfa yield was detected as the strongest factor, which simultaneously associated with the bacterial and fungal community composition, α-diversity, and β-diversity. Moreover, the abundance changes of predicted microbial functional genes revealed that improved alfalfa growth also resulted in more nutrient exhaustion and organic matter depletion in those soils under SSM and SSD treatments. In addition, the changes in bacterial community structure were more sensitive than those in the fungal community structure to soil physicochemical properties and alfalfa growth. In conclusion, the SSM and SSD treatments have great potential to improve alfalfa growth and alter soil microbial community structures in the arid and semiarid areas of northern China.

Drought avoidance of warm‐season turfgrasses affected by irrigation system, soil surfactant revolution, and plant growth regulator trinexapac‐ethyl

AbstractA 2‐yr study was conducted to investigate the effect of subsurface drip irrigation (SDI), the soil surfactant Revolution (modified methyl‐capped block copolymer), and the plant growth regulator PrimoMaxx (a.i. trinexapac‐ethyl [TE]), on rooting, stolons, and rhizomes, percentage green turf coverage, and turf quality of ‘Princess 77’ bermudagrass [Cynodon dactylon (L.) Pers.] and ‘Sea Spray’ seashore paspalum (Paspalum vaginatum Sw.). Grasses were grown on a loamy sand and irrigated with potable or saline ground water at 50% of reference evapotranspiration. Stolon and rhizome weight were not affected by water quality, Revolution, or TE, but SDI plots had greater stolon (1.000 vs. 0.627 g m−2) and rhizome biomass (0.856 vs. 0.493 g m−2) than sprinkler‐irrigated plots. Grasses in drip‐irrigated control plots showed higher root length density (RLD) at 0–10‐cm depth (15.1 vs. 8.3 cm cm−3) and 10–40‐cm depth (7.2 vs. 4.9 cm cm−3) and higher root weight density (RWD) at 0–10‐cm depth (3.5 vs. 2.2 g cm−3) than their sprinkler‐irrigated counterparts. Both RLD and RWD correlated significantly with turfgrass quality (August and September) and green turf cover (July–September). Chemical treatments in combination with irrigation from a sprinkler system resulted in thinner roots and higher RLD at all depths in 2013 when values were compared with the untreated control. Revolution, TE, and SDI all enhanced grasses’ drought avoidance and turf quality, but chemical treatments did not appear to provide additional improvements to grasses in plots irrigated with SDI.

Grain Yield, Water Productivity, and Soil Nitrogen Dynamics in Drip Irrigated Rice under Varying Nitrogen Rates

Core Ideas Effect of lateral spacing and varying N levels on rice was studied under subsurface drip irrigation.Crop growth and yield, water and nitrogen use efficiencies of drip irrigated rice were assessed.Nitrogen (NH4–N and NO3–N) dynamics was studied before and after fertilizer application. Water and nitrogen (N) saving rice (Oryza sativa L.) technology is required to meet the future food demand with decreasing resource availability. This emphasizes the importance of micro irrigation systems in field crops. Given the context, the present study was performed to evaluate the effect of subsurface drip irrigation on rice grain yield, water and N use efficiency and soil N dynamics. A field experiment was conducted for rice cultivation (cultivar Naveen) under subsurface drip irrigation (DIR) with two lateral spacings (S40 and S60) and four N fertilizer levels (0, 50, 75, and 100% of recommended dose) and puddle‐transplanted rice (PTR) at N100 during dry season of 2012 to 2013 and 2013 to 2014. The results of the study revealed significant increase in grain yield with increase in N fertilizer level from N0 to N50 or N75 in DIR. At N75, the DIR resulted in 73% recovery of applied N and 32% saving of water while attaining similar grain yield (5043 kg ha−1 in S40N75 and 4851 kg ha−1 in S60N75) as of PTR‐N100. The N dynamics revealed higher NH4+−N and NO3−–N contents in 0‐ to 18‐cm layer in DIR compared with PTR. Both drip lateral spacings did not show any significant differences in grain yield, water and N use efficiency. Hence, the subsurface drip irrigation with 60 cm lateral spacing and 25 to 50% lower N application could increase the water and N use efficiency of rice with similar grain yield as of PTR.

Effect of sub-surface drip irrigation with water soluble fertilizers on fertilizer and water use efficiency

To evaluate the specialty water soluble fertilizer namely Ultrasol (09: 05: 33) for Sustainable Sugarcane Initiative (SSI) under sub-surface drip irrigation (SSDI), this study was conducted at Agricultural College and Research Institute, Madurai during 2013–14. The study was designed in RBD with three replications, with treatments as various methods of fertilizer application including, soil application and drip fertigation. Sugarcane seedlings (var Co 86032) raised from single bud chips were planted (dual row) in trenches opened at 1.8 m, 40 cm width and 30 cm depth with 1.29 lph were placed in the centre of the trenches. SSDI was scheduled once in 3 days at 100% PE and fertigation was given based on crop growth demand at weekly interval from 15 to 210 DAP. Drip fertigation of 100% RDF with Ultrosol, MAP and Urea (F7) resulted in significantly highest the fertilizer use efficiency (FUE) (390.1 kg ha−1 cane yield N+P2O5+K2O applied) and higher water use efficiency (WUE) (120.28kg ha−1 mm−1) in Sustainable Sugarcane Initiative (SSI).

Subsurface drip irrigation enhances soil nitrogen and phosphorus metabolism in tomato root zones and promotes tomato growth

To understand the effects of subsurface drip irrigation (SDI) on soil microorganisms and the soil microbial mechanism underlying yield improvement, we performed field experiments to investigate the microbial community composition and function and the “soil-plant-microorganism” interactions in root zones. The results showed that the compositions of soil bacteria under surface drip irrigation with plastic film mulching (DI-PFM) and SDI were significantly different; the relative abundance of bacteria that metabolize organic matter was lower under SDI than under DI-PFM, but the relative abundance of nitrogen- and phosphorus-metabolizing bacteria was significantly higher under SDI than under DI-PFM. The depth of the drip irrigation tape was an important factor affecting soil microbes. With a drip irrigation tape depth of 20cm, soil porosity and root growth were greatly improved, thus strengthening the “soil-plant-microorganism” interactions, as were the soil urease and phosphatase activities at the peak fruiting stage and the soil available nitrogen and phosphorus contents. Furthermore, the absorption and utilization of nitrogen and phosphorus by tomato were promoted; the total nitrogen and phosphorus contents in the tomato root were 1.18 and 1.47 times higher, respectively, than those under DI-PFM. Similarly, the total nitrogen and phosphorus contents in the tomato stem were 1.11 and 1.66 times higher, respectively. The tomato yield per plant was 22.47% higher than that under DI-PFM, while the contents of soluble protein, vitamin C and lycopene of the tomato fruit were also significantly increased, resulting in improved fruit quality. With a drip irrigation tape depth of 30cm, tomato root length and forks were also remarkably improved, and nitrogen absorption by the tomato root was significantly enhanced. Although the tomato yield per plant was not significantly different from that with a drip irrigation tape depth of 20cm, the soluble protein, vitamin C and lycopene contents of the tomato fruit were significantly decreased. Taken together, a drip irrigation tape depth of 20cm is the most appropriate irrigation arrangement for tomato cultivation and production.

Productivity of Onions Using Subsurface Drip Irrigation versus Furrow Irrigation Systems with an Internet Based Irrigation Scheduling Program

Selection of the proper irrigation method will be advantageous to manage limited water supplies and increase crop profitability. The overall objective of this study was to evaluate the effect of subsurface drip irrigation (SDI) and furrow irrigation on onion yield and irrigation use efficiency. This study was conducted in two locations, a commercial field and a field located at the Texas A&M AgriLife Research Center in Weslaco, TX. This study was conducted as a split-plot design for both sites with two treatments (SDI and furrow irrigation) and three replications per treatment. The total onion yield obtained with the SDI systems was more than 93% higher than the yield obtained with furrow irrigation systems. The large onion size was 181% higher for the SDI system than the furrow system in both sites. The colossal size yield was also higher. At one site colossal yield was 206% higher than furrow, while at another site furrow yielded no colossal onions and SDI had some production. It was concluded that drip irrigation systems more than double yields and increased onion size while using almost half of the water. This was due to SDI allowing for more frequent and smaller irrigation depths with higher irrigation efficiency than furrow irrigation systems.

Winter wheat with subsurface drip irrigation (SDI): Crop coefficients, water-use estimates, and effects of SDI on grain yield and water use efficiency

Winter wheat (Triticum aestivum L.) production in the North China Plain (NCP) is threatened by insufficient water supply. Interest in microirrigation is increasing in the NCP, while data and guidance for microirrigation scheduling are lacking. An accurate estimation of actual crop evapotranspiration (ETa) is critical for appropriate water management. In this study, therefore, the SIMDualKc model was calibrated with the data from a three-season experiment, and ETa of winter wheat with subsurface drip irrigation (SDI) was estimated with the dual crop coefficient approach and stress adjustments described in the FAO-56 using the data of the other two treatments. The mean value of basal crop coefficient (Kcb) for the winter wheat at the initial-, mid-, and late-season growth stages over the three seasons was 0.25, 1.06, and 0.34, respectively. Over the three growing seasons, the ETa for subsurface drip-irrigated wheat with three irrigation treatments ranged from 393 to 449mm. The Kc-local (ETa/ETo) values for the winter wheat with SDI were 0.34–0.80, 0.91–1.11, and 0.41–0.98, respectively, at the initial-, mid-, and late-season growth stages. Results indicated that the procedure of the dual Kc approach and stress adjustments simulated ETa of the winter wheat reasonably well, with the average absolute error (AAE) of 0.36mmd−1, the root mean square error (RMSE) of 0.43mmd−1,the index of agreement (d) of 0.98, the Nash–Sutcliffe efficiency (NSE) of 0.91, and the RMSE-observations standard deviation ratio (RSR) of 0.31. Discrepancy between the simulated and measured data was mainly attributed to the assumption of a uniform distribution of soil water around an emitter. Irrigation rates have significant effects on ETa, grain yield and WUE. Based on effects of irrigation rates on grain yield and WUE, irrigation schedule for optimum yield and WUE was developed for winter wheat. It was estimated that grain yield and WUE of winter wheat with the optimum irrigation schedule was 7780kgha−1 and 1.83kgm−3, respectively. The simulated results can be used as a reference for irrigation schedule and water management for winter wheat in the NCP.

Effects of Subsurface Drip Irrigation and Different Planting Arrangements on the Yields and Technological Quality of Sugarcane

AbstractThe objective of this work was to evaluate the effects of subsurface drip irrigation (SDI) and sugarcane spacing on stem yields, sugarcane technological quality, and the theoretical recoverable sugar yields during four cycles of sugarcane cultivation. The experimental field was set up in randomized blocks treated with three planting row spaces (1.5 m, 1.8 m, and a double row planting scheme with 1.3×0.5 m between the planting rows) and subdivided into fertigated and nonirrigated sections. The following parameters were analyzed: percentage of soluble solids contained in the juice (brix), percentage of apparent sucrose in the juice (Pol), total recoverable sugar (TRS), stem yield, and the theoretical recoverable sugar yield. The data were evaluated using analyses of variance, and mean values were compared using Duncan’s test with significance accepted at the 5% probability level. The results showed that irrigation increased stem yields in the ratoon cane cycles and that the theoretical recoverable ...

Effect of New Irrigation Technology on the Physiology and Water Use Efficiency of Potato by Reclaimed Water Irrigation

Agriculture is a big consumer of fresh water in competition with other sectors of the society. The agricultural sector continues to have a negative impact on the ecological status of the environment. The worlds interest in high quality food is increasing. Field experiments were conducted to investigate the effect of subsurface drip irrigation on physiological responses, yield and water use efficiency, Soil nitrogen, Root weight density of potato in the semi-humid region of middle China using subsurface drip irrigation. The experiment used second-stage treated wastewater with and without addition of chloride, and both subsurface drip and furrow irrigations were investigated. Results indicated that the alternate partial root-zone irrigation is a practicable water-saving strategy for potato. The drip with chlorinated and non-chlorinated water improved water use efficiency by 21.48% and 39.1%, respectively, and 44.1% in the furrow irrigation. Partial root zone drying irrigation stimulates potato root growth and enhances root density. The content of the heavy metal in the potato tubers is no more than the National Food Requirements, and it is consistent with National Food Hygiene Stands.

Cana-de-açúcar fertirrigada com vinhaça e adubos minerais via irrigação por gotejamento subsuperficial: ciclo da cana-planta

O objetivo do trabalho foi avaliar o efeito da irrigação, a aplicação de vinhaça e fertirrigação mineral via irrigação por gotejamento enterrado nos valores biométricos na fase de maturação, produção de colmos, qualidade do caldo da cana-de-açúcar e rendimento de açúcar teórico recuperável. O experimento foi instalado em blocos ao acaso, com quatro tratamentos e cinco repetições. Os tratamentos foram: adubação mineral sem irrigação; irrigação e fertirrigação de NPK com adubos minerais; irrigação e fertirrigação com vinhaça, suprindo o K e complementação do NP com adubos minerais, além de irrigação e fertirrigação com vinhaça, suprindo o NK e complementação do P com adubos minerais. O sistema de irrigação utilizado foi o gotejamento subsuperficial. Os tratamentos irrigados promoveram alterações no número de perfilhos e índice de área foliar quando comparados com o cultivo de sequeiro, independente do manejo da fertirrigação. A fertirrigação com vinhaça suprindo o K proporcionou maior Brix e produção de colmos, quando comparada ao cultivo não irrigado. A irrigação e a fertirrigação com a vinhaça atendendo ao NK, proporcionaram maior rendimento teórico de açúcar recuperável, quando comparado com o do cultivo sem irrigação.

Simulation of point source wetting pattern of subsurface drip irrigation

Laboratory experiments and calculations were carried out to analyze the effect of subsurface drip irrigation (SDI) design features on soil wetting patterns for a point source. Experimental and simulated soil wetting patterns, using the SWMS-2D (simulating water movement and solute transport in two-dimensional) Galerkin finite element model, were investigated to maximize the efficiency of water saving. The analysis addressed the influence of water pressure head, back pressure and emitter diameter on wetting patterns. Predictions of water content distributions in the soils made with SWMS-2D were found to be in good agreement with the observed data. Results showed that this model provides confidence that model predictions are not too sensitive to back-pressure effects.

Bioenergy from Coastal bermudagrass receiving subsurface drip irrigation with advance-treated swine wastewater

Coastal bermudagrass ( Cynodon dactylon L.) may be a potentially important source of bio-based energy in the southern US due to its vast acreage. It is often produced as part of a waste management plan with varying nutrient composition and energy characteristics on fields irrigated with livestock wastewater. The objective of this study was to determine the effect of subsurface drip irrigation with treated swine wastewater on both the quantity and quality of bermudagrass bioenergy. The treated wastewater was recycled from an advanced treatment system and used for irrigation of bermudagrass in two crop seasons. The experiment had nine water and drip line spacing treatments arrayed in a randomized complete block-design with four replicates. The bermudagrass was analyzed for calorific and mineral contents. Bermudagrass energy yields for 2004 and 2005 ranged from 127.4 to 251.4 MJ ha −1. Compared to irrigation with commercial nitrogen fertilizer, the least biomass energy density was associated with bermudagrass receiving treated swine wastewater. Yet, in 2004 the wastewater irrigated bermudagrass had greater hay yields leading to greater energy yield per ha. This decrease in energy density of wastewater irrigated bermudagrass was associated with increased concentrations of K, Ca, and Na. After thermal conversion, these compounds are known to remain in the ash portion thereby decreasing the energy density. Nonetheless, the loss of energy density using treated effluent via SDI may be offset by the positive influence of these three elements for their catalytic properties in downstream thermal conversion processes such as promoting a lesser char yield and greater combustible gas formation.

Effect of subsurface drip irrigation on onion yield

Subsurface drip system is the latest method of irrigation. The design of subsurface drip system involves consideration of structure and texture of soil, and crop’s root development pattern. A 3-year experiment was conducted on onion (Allium Cepa L., cv. Creole Red) in a sandy loam soil from October to May in 2002–2003, 2003–2004 and 2004–2005 to study the effect of depth of placement of drip lateral and different levels of irrigation on yield. Tests for uniformity of water application through the system were carried out in December of each year. Three different irrigation levels of 60, 80 and 100% of the crop evapotranspiration and six placement depths of the drip laterals (surface (0), 5, 10, 15, 20 and 30 cm) were maintained in the study. Onion yield was significantly affected by the placement depth of the drip lateral. Maximum yield (25.7 t ha−1) was obtained by applying the 60.7 cm of irrigation water and by placing the drip lateral at 10 cm soil depth. Maximum irrigation water use efficiency (IWUE) (0.55 t ha−1 cm−1) was obtained by placing the drip lateral at 10 cm depth. The greater vertical movement of water in the sandy-loam soil took place because of the predominant role of gravity rather than that of the capillary forces. Therefore, placement of drip lateral at shallow depths is recommended in onion crop to get higher yield.

Effect of Subsurface Drip Irrigation on Cotton Plantations

During the cultivation periods of 2001 (a dry year) and 2002 (a wet one), an experimental cotton field was irrigated using a subsurface and a surface drip system. Both systems included drip-lines 17-mm in diameter, with emitters discharging 3.8 l/h and spacing 1 m. The treatments included four irrigation levels. These were equal to 120%, 100%, 80% and 60% of the net crop water requirements during each irrigation interval. For their calculation the FAO56–Penman–Monteith methodology that estimates crop evapotranspiration was utilised. From the statistical analysis of the harvested cotton plantations it has been found that during the dry year (2001) the seed cotton yields were significantly higher where the subsurface irrigation system was used and the irrigation applications met the 80% and 60% of the crop water needs. During the two experimental years the higher irrigation applications, 120% and 100% of the crop water needs, gave seed cotton yields that did not differ significantly for both systems (subsurface and surface).

Interaction Between Water and Nitrogen Application on Yields and Water-use Efficiency of Tomato and Pepper in Sandy Soil

Several practices have been adopted to minimize water use and potential N leaching of vegetable production systems, including use of drip irrigation, plastic mulch, and fertigation. However, these practices may not be adequate on sandy soils with poor water and nutrient retention capacities. The objectives of this study were to evaluate the interactive effects of irrigation practices and fertilizer rates on yield, fertilizer requirements, and N-leaching of pepper and tomato production systems. Bell pepper and tomato were planted on plastic mulched to evaluate the effects of three nitrogen (N) fertilizer rates (154, 192, 288 kg·ha -1 N for pepper vs. 166, 208, and 312 kg·ha-1 N for tomato) and three irrigation scheduling methods were evaluated. Depending on sensor readings, soil moisture sensor (SMS) irrigation treatments allowed up to five watering events per day where as for the fixed duration treatment irrigation was applied once a day. For tomato, the effect of subsurface drip irrigation (SDI) was also evaluated. Compared to TIME, use of SMS control system reduced water use by 29& to 44% and 37% to 66% for tomato and pepper, respectively. Tomato yield was significantly higher on SMS and SDI treatments compared to TIME treatments. For pepper yield and biomass accumulation were not affected by irrigation treatments. The average yields were 24.6 and 27.8 Mg·ha-1 of fresh marketable fruits for pepper and tomato, respectively. Nitrogen rate did not affect yield and optimal yield N rate did not affect yield for either crop. On average, SMS treatments increased irrigation water use efficiency 2–3 times compared to TIME treatments for both tomato and pepper.

Effect of subsurface drip irrigation on processing tomato yield, water table depth, soil salinity, and profitability

The potential of subsurface drip irrigation of processing tomatoes to reduce subsurface drainage, control soil salinity, and increase farm profits in areas affected by saline, shallow ground water was evaluated at three fields with fine-textured, salt-affected soil along the west side of the San Joaquin Valley of California. No subsurface drainage systems were installed in these fields. Yield and quality of tomato of the drip systems were compared with sprinkler irrigation. Yield increases of 12.90–22.62 Mg/ha were found for the drip systems compared to the sprinkler systems with similar amounts of applied water. Soluble solids of the drip-irrigated tomatoes were acceptable. Response of water table levels during drip irrigation showed that properly managed drip systems could reduce percolation below the root zone. Yields of the drip systems were similar over the range of soil salinity levels that occurred near the drip lines. Profits under drip irrigation were 867 to $ 1493 ha−1 more compared to sprinkler irrigation, depending on the amount of yield increase and the interest rate used in the economic analysis.

Effect of subsurface drip irrigation on processing tomato yield, water table depth, soil salinity, and profitability

The potential of subsurface drip irrigation of processing tomatoes to reduce subsurface drainage, control soil salinity, and increase farm profits in areas affected by saline, shallow ground water was evaluated at three fields with fine-textured, salt-affected soil along the west side of the San Joaquin Valley of California. No subsurface drainage systems were installed in these fields. Yield and quality of tomato of the drip systems were compared with sprinkler irrigation. Yield increases of 12.90–22.62 Mg/ha were found for the drip systems compared to the sprinkler systems with similar amounts of applied water. Soluble solids of the drip-irrigated tomatoes were acceptable. Response of water table levels during drip irrigation showed that properly managed drip systems could reduce percolation below the root zone. Yields of the drip systems were similar over the range of soil salinity levels that occurred near the drip lines. Profits under drip irrigation were 867 to $ 1493 ha −1 more compared to sprinkler irrigation, depending on the amount of yield increase and the interest rate used in the economic analysis.