Water Table Management Systems Research Articles

Design and performance of subirrigation system in maize (Zea mays) in Kumulur farm, Trichy district, Tamil Nadu, India

Subirrigation system can furnish water to plants. The upward flux and the discharge rate must satisfy the plant’s lifesaving irrigation needs during summer. The experiment was laid out in A-block of Eastern farm, Agricultural Engineering College and Research Institute, Kumulur, Trichy, Tamil Nadu. Subirrigation system spacing was arrived using Moody's equation calculated as 10 m. The experiment was laid out in spilt plot design with three replications. Four drain spacing levels (7.5, 10, 12.5 and 15 m) were the main plot treatments and two levels of depth and diameter of drain pipes (75 cm, 60 cm & 75 mm, 63 mm) were the sub plot treatments. The highest volumetric water content was recorded in 7.5 m spacing + 45 cm soil depth + lower reach (S1T3T1). Capillary rise on water table management system under subirrigation mode was fixed as 33.5 cm and the average deep percolation loss was obtained in 0.3 cm/d at development stage of crop period. The highest maize yield (4.30 t/ha) was obtained in 7.5 m spacing + 60 cm drain depth + 75 mm diameter (S1D3). The highest water use efficiency of (0.86 kg/m3) was recorded in 7.5 m spacing + 60 cm drain depth + 75 mm drain diameter (S1D3). This subirrigation system could furnish water to plants due to upward flux and the same system also functioned efficiently under drainage modes and removed the waterlogging during wet periods.

Nitrous oxide emissions as affected by fertilizer and water table management under a corn-soybean rotation

Nitrous oxide (N2O) emissions from agricultural soils are influenced by several factors, including fertilizer and water management. A 4-year study (2012–15) was conducted to evaluate the impact of different types of fertilizer and water table management systems on N2O emissions under a corn-soybean rotation. The types of fertilizers assessed were inorganic fertilizer (IF) and a combination of inorganic fertilizer and solid cattle manure (SCM) (applied in 2012 and 2014, for corn only), while the water table management systems were regular tile drainage (DR), and controlled drainage with sub-irrigation (CDS). The IF and SCM were combined with DR and CDS in separate plots arranged as a two by two factorial design. The results show that, in 2012, 2013 and 2014, N2O fluxes were significantly (2012, 2013 p < 0.05; 2014 p < 0.1) affected by the fertilizer treatments. In 2012 and 2014, when fertilizer was applied to corn, the emissions were greater from IF than SCM; however, in 2013, under soybean cultivation, the emissions were greater from SCM than IF, indicating slow mineralization of SCM fertilizer compared to IF. In 2014, under corn and 2015 under soybean, the N2O fluxes were significantly higher (P < 0.05) from DR compared to CDS plots indicating a greater reduction of N2O to dinitrogen (N2) via denitrification. The results also showed that early in the growing season, high N2O fluxes were observed following planting due to fertilizer application, precipitation in excess of 100 mm per month in the early growing season, and spring tillage. The N emission factors of IF-DR, IF-CDS, SCM-DR, and SCM-CDS were 1.2, 0.9, 1.0, and 0.5, respectively. This study concludes that the combination of SCM and CDS is the most efficient at reducing N2O emissions while maintaining sustainable yields in a corn-soybean rotation.

多雪重粘地における不耕起V溝直播水稲–大麦–大豆2年3作体系での作土の孔隙特性の変化

多雪重粘地における不耕起V溝直播水稲–大麦–大豆2年3作体系での作土の孔隙特性の変化

多雪重粘土地帯の地下水位制御システム(FOEAS)圃場における水位制御がオオムギの収量に与える影響

多雪重粘土地帯の地下水位制御システム(FOEAS)圃場における水位制御がオオムギの収量に与える影響

Impact of Different Water Management Scenarios on Corn Water Use Efficiency

Abstract. This study investigated the water balance, crop yield, and water use efficiency (WUE) of a water table management system compared to a conventional drainage system at three nitrogen levels. A two-year field study was conducted using three blocks; each block was composed of two water management treatments: controlled drainage with subirrigation (CD-SI) and conventional or free drainage (FD). The water table depth was maintained at 60 cm below the soil surface in the CD-SI plots. Three nitrogen treatments (low, medium, and high) were applied in strips across all blocks. The seasonal water balance indicated surplus water conditions in the CD-SI plots, while the FD plots had deficit conditions. In 2008 and 2009, the corn grain WUE for the FD plots was 2.49 and 2.46 kg m -3 respectively. The corn grain WUE for the CD-SI plots was 2.43 and 2.26 kg m -3 in 2008 and 2009, respectively. The WUE of corn grain responded to the water treatments (p 0.05) on grain yields at the normal nitrogen level. Furthermore, the two water treatments had no effect on the aboveground dry biomass yields in both years.

Reducing nitrate loss in tile drainage water with cover crops and water-table management systems.

Nitrate lost from agricultural soils is an economic cost to producers, an environmental concern when it enters rivers and lakes, and a health risk when it enters wells and aquifers used for drinking water. Planting a winter wheat cover crop (CC) and/or use of controlled tile drainage-subirrigation (CDS) may reduce losses of nitrate (NO) relative to no cover crop (NCC) and/or traditional unrestricted tile drainage (UTD). A 6-yr (1999-2005) corn-soybean study was conducted to determine the effectiveness of CC+CDS, CC+UTD, NCC+CDS, and NCC+UTD treatments for reducing NO loss. Flow volume and NO concentration in surface runoff and tile drainage were measured continuously, and CC reduced the 5-yr flow-weighted mean (FWM) NO concentration in tile drainage water by 21 to 38% and cumulative NO loss by 14 to 16% relative to NCC. Controlled tile drainage-subirrigation reduced FWM NO concentration by 15 to 33% and cumulative NO loss by 38 to 39% relative to UTD. When CC and CDS were combined, 5-yr cumulative FWM NO concentrations and loss in tile drainage were decreased by 47% (from 9.45 to 4.99 mg N L and from 102 to 53.6 kg N ha) relative to NCC+UTD. The reductions in runoff and concomitant increases in tile drainage under CC occurred primarily because of increases in near-surface soil hydraulic conductivity. Cover crops increased corn grain yields by 4 to 7% in 2004 increased 3-yr average soybean yields by 8 to 15%, whereas CDS did not affect corn or soybean yields over the 6 yr. The combined use of a cover crop and water-table management system was highly effective for reducing NO loss from cool, humid agricultural soils.

Discharge of water, nitrogen, phosphorus and suspended matter from clayey fields with a water table management system in a region with heavy snowfall during a two-year system of the V-furrow no-till direct seeding rice - winter barley - soybean triple cropping

Discharge of water, nitrogen, phosphorus and suspended matter from clayey fields with a water table management system in a region with heavy snowfall during a two-year system of the V-furrow no-till direct seeding rice - winter barley - soybean triple cropping

Selected Soil Physical Properties and Implications on Water Management System in Northeast Florida

Selected soil physical properties at varying depths in a cultivated Alfisol in northeast Florida were studied using classical and geostatistical techniques. The objective was to investigate the variation in the physical properties among and within the sampling depths and understand its implications to field water management in the area. Seventy soil core samples were collected in a grid sampling scheme from five depths: 22.5 cm, 45 cm, 67.5 cm, 90 cm, and 120 cm. Particle size distributions, bulk density (Db), and saturated hydraulic conductivity (Ks) of the soil samples from each depth were measured and statistically compared among depths, and the spatial variation of properties within each sampling depth was determined. Clay content and Db increased significantly with increasing depth, whereas the Ks decreased. The Ks exhibited the maximum variation in both vertical and horizontal direction, whereas Db was the least variable among the three properties. The semivariogram analysis showed a weak spatial autocorrelation in soil properties within the sampling depths. The results suggested that despite significantly low conductivity and high Db of the soil profile at 120 cm, it was not impermeable enough to restrict vertical water movement as opposed to the general perception of the occurrence of a shallow impermeable layer in the profile and consequent perched water table conditions. The results, therefore, provided a definitive insight into the water table management system in the area, which is important for understanding the irrigation system, its efficiency, and consequent water quality impacts on surface and/or groundwater.

Growing Rice Under Managed Water Table System:

A lot of water is used in rice cultivation but under dwindling global water stocks, this issue of water use must be examined. Therefore rice (Oryza sativa L.) cultivar IR36 was grown in a controlled sand medium under nitrogen limiting conditions using a water table management system. The treatments used were water table at depths of 27.5cm, 15cm below the surface and saturated sand with the water table at the soil surface. Fifty four rice plants were grown for a period of 68 days. There were five harvests, with 9 plants harvested at each of the first four and 18 plants at the last harvest. Plant growth was determined by measuring rooting depth when harvesting, and the rest, shoot length, root dry mass and shoot dry mass after harvest. The saturated treatment was highest for all parameters measured followed by the 15cm and finally the 27.5cm treatment. The water release characteristics indicated that there were no major differences between moisture contents when the water table was held at the depths used. For most of the parameters measured, significant differences emerged only after about 25 days after seeding indicating that there was the possibility of some water saving in the early days of rice production. Contrary to other findings, the rooting depth for the saturated treatment was higher than those for the 15cm and 27.5cm treatments, a factor, which could be attributed to the fact that rooting depth is greater when nitrogen is limiting. Journal of the Ghana Science Association Vol. 10 (2) 2008: pp. 39-50

Water table management impacts on phosphorus loads in tile drainage

Increased phosphorus (P) concentrations, consistently exceeding Quebec's surface water quality standard of 0.03 mg L −1 total P, caused increased P loads in tile drainage from controlled drainage/subirrigation (CD/SI) plots compared to free drainage (FD) plots in a field study carried out in 2005 in Coteau-du-Lac (southwestern Quebec, Canada). This happened even though the total outflow volumes from CD/SI plots were reduced by 27% compared to FD plots. Of the total P concentration, around 96% was in the form of dissolved P under both treatments. The results also showed that CD/SI had no effect on the soil P concentration and P saturation. During the experiment, the SI water added about 0.84 kg P ha −1, which was negligible compared to the fertilizer input on the field, but represented about 8.5 times the average total P loss from CD/SI plots. However, a laboratory soil column experiment, in which the two drainage treatments were simulated and P-free water was used for SI, also showed increased P concentrations under CD/SI. This confirmed that the increased P loads in tile drainage under CD/SI were most likely caused by an increase in P solubility due to the shallow water table inherent to the water table management system rather than by the addition of P from the SI water.

Subsurface Irrigation as a Microbial Delivery Tool for Bioaugmentation: Transport, Distribution and Survival in Large Packed Soil Columns

Traditionally, soil surface inoculation and surface irrigation are used for delivery, transport and distribution of bacteria for agricultural and in-situ environmental decontamination applications. The objective of this study was to test whether subsurface irrigation with a water table management (WTM) system, successfully used previously for nutrient delivery, could also be used to deliver bacteria to soil depths. Twelve stainless steel columns, 1000 mm in length and 200 mm in diameter, were packed with a sandy loam soil. Four experimental treatments, two subsurface irrigation and two surface irrigation, were randomly allocated, in triplicate, to the twelve columns. The transport, implantation and survival of Sinorhizobium (Rhizobium) meliloti, strain A-025, in these columns were monitored at different depths and times after surface and subsurface irrigation. Even though the transport of bacterial cells was slower with the subsurface irrigation regime than with surface irrigation, more bacteria were implanted at different depths with subsurface irrigation. The numbers of bacterial cells distributed with subsurface irrigation were 1.6×105, 1.3×105, 2.6×105 and 2.9×105 cfu (colony forming units) ·g−1 of soil at 60, 300, 500 and 700 mm depths, respectively, whereas with surface irrigation the numbers were 2.0×104, 3.0×104, 1.9×105, 9.0×102 cfu·g−1 of soil. These results clearly indicate that subirrigation can be used effectively to bioaugment a sandy loam soil matrix.

Efeito de três manejos do lençol freático na adaptação fisiomorfológica do feijoeiro (Phaseolus vulgaris, L.) ao encharcamento

Estudou-se o efeito de três manejos do lençol freático na indução de adaptações fisiomorfológicas do cultivar Bat 477 de feijão (Phaseolus vulgaris, L.) à hipoxia, com vistas em caracterizar a influência relativa dos principais fatores físicos, químicos e biológicos interferentes. O experimento foi realizado em campo, na ESALQ/USP, Piracicaba (SP), de março a junho de 1999, utilizando-se caixas de cimento amianto de 1.000 L como unidade experimental no delineamento de parcelas inteiramente ao acaso, com quatro tratamentos e cinco repetições. As caixas receberam estrutura própria de manejo e controle do lençol freático. Simulou-se ao máximo um meio físico/condição natural de uma várzea. Após a indução no período vegetativo, a eficiência dos manejos foi testada pela inundação temporária do solo no fim do florescimento/formação de vagens. Houve um efetivo processo de nodulação das raízes, a despeito da condição de alta saturação do solo. As características biométricas de crescimento, embora acusando prejuízo da hipoxia, evidenciaram a utilização pela planta de mecanismos adaptativos morfológicos (raízes adventícias e lenticelas), biológicos (fixação de N) e fisiomorfológicos (resistividade estomática e transpiração). Já as características biométricas de colheita evidenciaram que tanto o manejo do lençol mantido a 15 cm como o de elevação gradativa, embora com rendimento de grãos sem vantagem estatística sobre o manejo não-indutivo, foram efetivos, permitindo a planta completar seu ciclo, além de menor comprometimento na qualidade de grãos. A alternância de vantagens relativas biométricas entre os dois manejos não acarretou diferença estatística no rendimento de grãos, levando-se a inferir ser vantajoso o uso de cultivares de ciclo mais longo nesse tipo de condição.

Biofiltration of Residual Fertilizer Nitrate and Atrazine by Rhizobium meliloti in Saturated and Unsaturated Sterile Soil Columns

This study was undertaken to investigate whether microbial bioaugmentation of subsurface soil with subsurface irrigation could be used as a biofiltration/biocontrol technology for agricultural pollutants. Nine Plexiglas columns, 458 mm long x 139 mm in diameter, were packed with a sterilized sandy loam soil. Subsurface irrigation, through a controlled water table management system, was used to deliver bacteria, Rhizobium meliloti A-025, to the soil and to maintain aerobic (unsaturated) or anaerobic (saturated) conditions in the columns. Nitrate and atrazine, a fertilizer and a corn herbicide, were applied to the soil surface, and leaching was affected by simulated rainfall events. The soil and drainage waters were analyzed for nitrate and atrazine residues after each rainfall simulation throughout the experimental period during which the soil was kept saturated for a total of 80 days and unsaturated for a total of 70 days. The monitoring of transport and survival of the implanted bacterial strain (A-025) showed that subsurface irrigation was successful in introducing and transporting the bacteria throughout the soil columns. During the saturated period, significantly more (95% probability) nitrate-N leached into the drainage waters from the control columns than from the bioaugmented columns; the increase being 450% or more for the abiotic control columns. The amount of atrazine that leached into the drainage waters during the unsaturated period was also significantly more from control columns as opposed to bioaugmented columns, with the increase being 262%.

Bioremediation of residual fertilizer nitrate: I. Laboratory demonstration of an on-farm in situ pollution control system.

This exploratory laboratory study was undertaken to develop and test an in situ bioremediation system intended to point the way toward a possible field application. The proposed method uses a water table management (WTM) system to deliver nutrients or other amendments to subsoil microorganisms for biostimulation and subsequent biodegradation of pollutants in the saturated and unsaturated zones of the soil. The study was carried out on packed soil columns and bioremediation of residual fertilizer nitrate was attempted. Different levels of organic carbon supplement (glucose C) were introduced into these columns via subirrigation in order to supplement the readily available organic carbon levels in the soil. The study was carried out in two experimental setups. The first setup investigated (i) the effect of addition of a high (970 mg L(-1)) and a low (120 mg L(-1)) glucose C level and (ii) the efficacy of using the subirrigation system as a method for nutrient delivery in bioremediation of leached nitrate. This setup was monitored with time, depth, and with reference to the nitrate residue in the soil solution. Leached nitrate was denitrified to less than 10 mg L(-1) nitrate N at both glucose levels. The second setup investigated the effect of a range of low levels of glucose C on nitrate decontamination, soil pH, and total microbial count in order to find out an optimal glucose C level that reduced the most nitrate and maintained the pH homeostasis of soil.

Bioremediation of residual fertilizer nitrate: II. Soil redox potential and soluble iron as indicators of soil health during treatment.

The prospect of using wastewater containing high loads of soluble organic matter (OM) for removing residual agricultural chemicals (fertilizer, pesticide, or herbicide) in farm soil, although promising, could have adverse effects on soil agricultural quality as a result of development of redoximorphic features in the soil profile. In this study, the effect of organic carbon supplement for bioremediation of residual fertilizer nitrate on soil properties, redox potential (Eh), pH, and metal ion mobilization was studied using sandy soils packed in columns. The study was included in a general project, described elsewhere (Ugwuegbu et al., 2000), undertaken to evaluate use of controlled water table management (WTM) systems to supply organic carbon for creating a reduced environment conducive to denitrification of residual fertilizer nitrate leaching from the farm to subsurface water. The columns were subjected to subirrigation with water containing soluble organic carbon in the form of glucose. The work was carried out in two experimental setups and the long-term effect of a range of glucose concentrations on the Eh, pH, and soluble levels of Fe and Mn was investigated. From the results obtained, it could be concluded that excessive organic carbon supplement to soil can have adverse effects on soil quality and that Eh and soluble Fe are the two most practical parameters for monitoring soil health during treatment of farm chemicals.

Water table management reduces tile nitrate loss in continuous corn and in a soybean-corn rotation.

Water table management systems can be designed to alleviate soil water excesses and deficits, as well as reduce nitrate leaching losses in tile discharge. With this in mind, a standard tile drainage (DR) system was compared over 8 years (1991 to 1999) to a controlled tile drainage/subirrigation (CDS) system on a low-slope (0.05 to 0.1%) Brookston clay loam soil (Typic Argiaquoll) in southwestern Ontario, Canada. In the CDS system, tile discharge was controlled to prevent excessive drainage, and water was pumped back up the tile lines (subirrigation) to replenish the crop root zone during water deficit periods. In the first phase of the study (1991 to 1994), continuous corn (Zea mays, L.) was grown with annual nitrogen (N) fertilizer inputs as per local soil test recommendations. In the second phase (1995 to 1999), a soybean (Glycine max L., Merr.)-corn rotation was used with N fertilizer added only during the two corn years. In Phase 1 when continuous corn was grown, CDS reduced total tile discharge by 26% and total nitrate loss in tile discharge by 55%, compared to DR. In addition, the 4-year flow weighted mean (FWM) nitrate concentration in tile discharge exceeded the Canadian drinking water guideline (10 mg N l) under DR (11.4 mg N l), but not under CDS (7.0 mg N l). In Phase 2 during the soybean-corn rotation, CDS reduced total tile discharge by 38% and total nitrate loss in tile discharge by 66%, relative to DR. The 4-year FWM nitrate concentration during Phase 2 in tile discharge was below the drinking water guideline for both DR (7.3 mg N l) and CDS (4.0 mg N l). During both phases of the experiment, the CDS treatment caused only minor increases in nitrate loss in surface runoff relative to DR. Hence CDS decreased FWM nitrate concentrations, total drainage water loss, and total nitrate loss in tile discharge relative to DR. In addition, soybean-corn rotation reduced FWM nitrate concentrations and total nitrate loss in tile discharge relative to continuous corn. CDS and crop rotations with reduced N fertilizer inputs can thus improve the quality of tile discharge water substantially.

PREDICTION OF ANNUAL NITRATE-N LOSSES IN DRAIN OUTFLOWS WITH ARTIFICIAL NEURAL NETWORKS

An artificial neural networks (ANN) model was developed for the prediction of annual nitrate-N (NO3-N) losses into the drain flow at Eugene F. Whelan Experimental Farm (Agriculture Canada, Woodslee, Ontario, Canada). Data consisted of daily measurements of nitrate-N taken from eight different soil conservation treatments during 1992- 1994. The experiment consisted of four crop/tillage and two water table management systems. Due to the moderate size of the data set, a tenfold cross validation method was used for model validation. A sensitivity analysis was also performed to assess the effect of the input variables on the performance of the networks. The results of this study indicated that the performance of network predictions of nitrate-N was highly satisfactory for 6 of the treatments and acceptable for the remaining two. The sensitivity analysis demonstrated that network predictions of nitrate-N were not affected when either drain flow or evapotranspiration data were excluded from the network training files. Overall, this study reveals that, from adequate input information, Artificial Neural Networks could effectively predict loss of nitrate-N in drain outflows. While the ANN model itself is not transportable to any other site, it does provide another method of estimating nitrate-N losses from agricultural fields with fewer input parameters. In addition, they could also be used to identify the unnecessary parameters for ANN modeling and thus save valuable time and resources in data collection.

Water Table Management, Nitrogen Dynamics, and Yields of Corn and Soybean

Concern about NO−3 contamination of surface waters has prompted the development of agricultural water table management systems to reduce NO−3 loss in subsurface drainage outflow by subirrigating through the existing subsurface drainage lines during the growing season and controlling off‐season outflows. We hypothesized that soil N pools, crop yields, and N uptake in a corn (Zea mays L.)–soybean (Glycine max.) rotation differ between subirrigation (water table at 40 cm) with controlled drainage (SI/CD) vs. subsurface drainage (SD) alone on Omulga silt loam (Aeric Fragiaqualfs). Mean microbial biomass N, potentially mineralizable N, dissolved organic N, and ammonia N were not affected by the water table management system. Mean NO−3–N was not affected by the water table management system at 0‐ to 15‐cm and 15‐ to 30‐cm depths, but the 2‐yr mean soil NO−3 concentration at the 30‐ to 75‐cm depth was 46% lower in SI/CD compared with SD. The average corn yield was 19% greater, and the average soybean yield was 64% greater, in SI/CD plots, compared with SD. Corn N uptake was 13% greater and soybean N uptake was 62% greater with SI/CD, compared with SD. The SI/CD water table management system increased plant N uptake and reduced deep‐profile NO−3 concentrations, thereby reducing the amount of NO−3 potentially available to move via drains to surface waters.

INFLUENCE OF INTERCROPPING AND SUBIRRIGATION ON SOIL MOISTURE AND WATER TABLES UNDER MAIZE IN QUEBEC

Intercropping and water table management have become important tools in reducing nitrate leaching from fields under maize production in Quebec. However, the effects and interactions between these two management practices and soil moisture and water table fluctuations in the region have not been investigated. A water table management study was conducted in Soulanges County, Quebec during the summer of 1994. Three water table levels freely drained (1.0 m) and subirrigated to 0.5 m and 0.75 m from the ground surface; and two cropping systems; monocropped maize (Zea mays L.) and maize with ryegrass (Lolium multiflorum Lam.), were factorially combined. Soil moisture content (SMC) at three depths (0–0.15, 0.15–0.30, and 0.3–0.5 m), and water table depths (WTD) were monitored twice a week, and meteorological data were collected at the site. The 0.5 m and 0.75 m subirrigated plots provided the same SMC trends in both cropping systems, but the SMC in freely drained plots was always lower than in the subirrigated plots. The cropping system did not affect SMC in either water table management system. WTDs were greater in the freely drained plots than in the subirrigated plots. These results are discussed in the context of best management practices for corn production in Quebec.

EFFECTS OF WATER TABLE MANAGEMENT ON GROUNDWATER CONTAMINATION FROM THE USE OF PROMETRYN IN ORGANIC SOILS

In 1990, a two year study was undertaken to determine the effects of water table management on the movement of the herbicide prometryn in an organic soil in southern Québec. Three water table management systems were used: controlled drainage, subsurface irrigation, and subsurface drainage. Results indicate that most of the prometryn movement through soil and into groundwater occurred during the first few months following application. In the subsurface drainage field, the concentrations of herbicide in groundwater were mostly higher than the drinking water quality standard of 10 μg/L. When subirrigation or controlled drainage was used, the concentration fell significantly below this level, indicating their usefulness in reducing the amount of prometryn reaching the groundwater. The study also demonstrated that, in an organic soil, pesticide movement was affected mainly by the water balance. The negative water balance during dry periods caused the soil water and pesticide to move upwards. This phenomenon was enhanced when the water table was close to the soil surface and the contaminant was positioned higher in the soil profile, which improved the opportunity for degradation of the chemical before it reached the drains. On the other hand, during high rainfall events and periods of positive water balance, the contaminant was readily leached through the soil profile.