Controlled Drainage System Research Articles

Groundwater Potential Evaluation in the Crystalline Basement of Gidan Kwano Campus, Federal University of Technology, Minna, North-Central Nigeria Using Geoelectric Methods

Gidan Kwano campus of the Federal University of Technology, Minna, is located within the basement complex terrain of North-Central Nigeria and is underlain by Pre-Cambrian basement rocks of which granites are predominant. Vertical Electrical Sounding (VES) employing the Schlumberger electrode configuration was used to provide information about the subsurface lithology and structures with the aim of evaluating its groundwater potential. A total of 48 VES was made along eight profiles with six sounding stations per profile within an area of about 10km2. A combination of VES, Horizontal Resistivity Profile and Sounding – Profiling produced a subsurface geological appraisal of the study area. Results of the interpretations of VES data were used to produce fracture map and isopach map of depth to basement which has a mean value of 35 m. Interpreted fractures coincide with the direction of stream flow suggesting a structurally controlled drainage system. VES curves reveal that the area is generally characterized by three geoelectric layers. Top soil layer thickness range from 0.2m to 7.4 m while the weathered layer thickness range from 0.3 m to 58.8 m. Out of the 48 VES made, 8 VES stations have been selected as priority locations for the development of groundwater resources. The study area has been found to have a very high potential for groundwater development. Despite all the limitations of the VES technique, it has been found to be reliable for groundwater exploration in the basement complex terrain particularly when the Schlumberger Configuration combined with geological and computer - aided interpretation for the survey data is implemented.

Controlled drainage and subirrigation – A water management option to reduce non-point source pollution from agricultural land

Losses of nutrients from arable land significantly contribute to the eutrophication of lakes and coastal waters. Consequently agricultural nutrient and water management strategies have been emphasized during the last decades. The problem of excessive drainage at certain times of the year in conventional drainage systems (CD) can in many cases be overcome by implementing controlled drainage strategies (CWT). The data for this paper is based on water management projects, at both plot and field scales, which have been carried out in Southern Sweden during the period 2002 to 2005. The studies included water table strategies in which the subsoil was subjected to various degrees of water status at different times of the year by means of controlled drainage system. They were run on one site with small plots and two sites with field scale plots, and each site consisted of one CD plot and three CWT plots.Compared to CD, CWT had lower subsurface runoff all years of measurement. Nitrogen (N) and phosphorus (P) concentrations in subsurface drainage water revealed no significant differences between CWT and CD. N and P losses, in contrast, tended to be lower in CWT than in CD, possibly due to lower runoff volumes in CWT. The yearly losses of NO3-N, Total-N, PO4-P and Total-P through the drainage system were on average 40% lower in CWT than in CD. The yield and N uptake by crops, in most measurements, were higher in CWT due to more water available during the cropping season and thereby improved N efficiency of the applied fertiliser. The results from the experiments revealed that controlled drainage has a potential to lower non-point source leaching of nutrients from agricultural land, improve N and P use efficiency and increase yields.

Controlled drainage systems to reduce contaminant losses and optimize productivity from New Zealand pastoral systems

Drainage systems are essential for managing soil water levels, thereby ensuring optimal plant productivity while protecting soil quality. Although beneficial, drainage systems are also known to be a significant loss route for dissolved nutrients. A potential way of reducing nutrient loss through drainage systems is to use weirs to strategically control drainage of excess water from the soil profile. This review evaluates the scientific literature to ascertain whether controlled drainage could be a useful crop productivity and nutrient loss mitigation tool for New Zealand pastoral farming systems. While a range of risks and potential disadvantages have been identified, evidence from studies of cropped systems with controlled drainage in Europe, Canada and the US suggests that suitably managed controlled drainage offers significant benefits for water quality, agricultural productivity and nutrient- and water-use efficiency. The practical efficacy of controlled drainage requires field evaluation under New Zealand farming conditions.

An easy to use calculation method for weir operations in controlled drainage systems

If operated appropriately, drainage systems may serve as vast reservoirs to retain or release water and solutes. This paper describes the hydraulic principles ruling the unsteady reaction of groundwater levels as related to drainage control operations. A set of governing equations suited to be implemented in computer codes was deduced focusing on non steady-state drainage, weir hydraulics, and effects of ditch maintenance. Based upon a simplified layout, two easy to handle computer codes were developed (MATLAB/Octave and Excel versions) enabling local engineers to assess system performance. Controlled drainage systems may be used to reduce leaching of agrochemicals from agricultural land and are valuable tools for preventive flood control. Controlled drainage may further support effective field operations necessary for crop production.

Nitrogen balance in and export from agricultural fields associated with controlled drainage systems and denitrifying bioreactors

Nitrate loss from drainage tiles across the cornbelt of the upper midwestern US is a result of intensive agriculture with limited crop diversity, extensive periods of fallow soil, and the need for high fertilizer applications to corn, all located on a hydrologically modified landscape. Two methods proposed to reduce tile nitrate export are managed or controlled drainage to limit tile flow and bioreactors to enhance denitrification. Nitrogen budgets and tile flow monitoring were conducted over two- to three-year periods between 2006 and 2009. We estimated N budgets in a seed corn-soybean rotation farming system near DeLand, east-central Illinois, USA, with free (FD) and controlled drainage (CD) patterned tile systems. In addition, wood chip filled trenches (bioreactors) were installed below the CD structures, one lined with plastic and one unlined. We measured daily tile flow and nitrate-N (NO 3-N) concentrations and calculated cumulative N loss from the tile water at both FD and CD areas for a period of three cropping years. We also monitored the tile flow and nitrate concentration in inlet and outlet of the bioreactor associated with a CD system and evaluated the efficiency of the bioreactor for two cropping years. Most components of the N balance were unaffected by CD (yields and therefore N harvested, surface soil denitrification), and there was a negative N balance in the soybean cropping year (−165 and −163 kg N ha −1 at FD and CD areas, respectively), whereas seed corn cropping in the following year resulted in positive N balances (29 and 34 kg N ha −1 at FD and CD areas, respectively). For two years, the overall N balances were −136 and −129 kg N ha −1 at FD and CD areas, respectively, consistent with other recent corn belt studies showing a small net depletion of soil organic N. Controlled drainage greatly reduced tile N export, with a three-year average loss of 57.2 kg N ha −1 yr −1 from FD compared to 17 kg N ha −1 yr −1 for CD. There was high uncertainty in denitrification measurements and thus the fate of missing N in the CD system remained unknown. Nitrate reduction efficiency of the bioreactor varied greatly, with periods where nearly 100% of the nitrate was denitrified. The overall efficiency of the bioreactor associated with the CD system in reducing the tile N load was 33%. When nitrate was non-limiting, the nitrate removal rate of the bioreactor was 6.4 g N m −3 d −1. Little N 2O emission was found from the bioreactor bed and is not thought to be a problem with these systems. Both the tile bioreactor and controlled drainage greatly reduced tile nitrate export in this leaky seed corn and soybean agricultural field.

Assessment of a Large Subsurface Controlled Drainage and Irrigation System: III. Water chemistry of the tile effluent and its potential impact on surface water resources

Abstract Controlled subsurface drainage irrigation systems promote crop productivity; however, these land management systems also allow an efficient pathway for the transport of elements from soils to surface water resources. The nitrate and macro-element effluent concentrations from tile-drainage involving a 40 ha controlled subsurface drainage irrigation system are described and compared to soil nitrate availability. Soil nitrate concentrations generally show an increase immediately after soil nitrogen fertilization practices and are sufficiently abundant to promote their transport from the soil resource to the tile-drain effluent waters. The data indicates that: (1) the transport of nitrate-N in tile-drain effluent waters is appreciable; (2) denitrification pathways effectively reduce a portion of the soil nitrate-N when the controlled drainage system establishes winter-early spring anoxic soil conditions, and (3) the best strategy for reducing nitrate-N concentrations in tile-drain effluent waters is adjusting N fertilization rates and the timing of their application. The development of bioreactors for simulating wetland conditions may further limit nitrate concentrations in surface waters because of soil drainage.

Experimental study on the distribution of soil nitrate and ammonium nitrogen under controlled drainage

A field experimental project was set up to assess the effects of controlled drainage on the distribution and concentration of nitrogen in the soil at the Irrigation and Drainage Experimental Station under Four-Lake Engineering Administration of Jingzhou City, Hubei Province. Two plots drain runoff by controlled drainage system, with an area of 0.1 hm2 (20 m×50 m) each. The third one with an area of 0.04 hm2 (8 m×50 m) has a conventional subsurface drainage system. Under this experimental condition, the study draws the following conclusions: ① The controlled drainage system has a remarkable effect on the diminishing ratios of nitrate nitrogen between neighboring layers. It is presented that the diminishing ratio increases with the raising height of drain outlet. Controlled drainage system also reduces the transference of nitrate nitrogen in topsoil. ② Different from nitrate nitrogen, the concentration of ammonium nitrogen is stable along the longitudinal section of soil, which is little affected by the controlled drainage system. It indicates that the concentration of ammonium nitrogen decreases according to the lowering of controlling height of the drain outlet.

The effect of salinity on water productivity of wheat under deficit irrigation above shallow groundwater

Saline groundwater is often found at shallow depth in irrigated areas of arid and semi-arid regions and is associated with problems of soil salinisation and land degradation. The conventional solution is to maintain a deeper water-table through provision of engineered drainage disposal systems, but the sustainability of such systems is disputed. This shallow groundwater should, however, be seen as a valuable resource, which can be utilised via capillary rise (i.e. sub-irrigation). In this way, it is possible to meet part of the crop water requirement, even where the groundwater is saline, thus decreasing the need for irrigation water and simultaneously alleviating the problem of disposing of saline drainage effluent. Management of conditions within the root zone can be achieved by means of a controlled drainage system. A series of lysimeter experiments have permitted a detailed investigation of capillary upward flow from a water-table controlled at shallow depth (1.0 m) under conditions of moderately high (5 mm/day) evaporative demand and with different levels of salinity. Experiments were conducted on a wheat crop grown in a sandy loam soil. Groundwater salinity was held at values from 2 to 8 dS/m while supplementary (deficit) irrigation was applied at the surface with salinity in the range 1–4 dS/m. Our experiments show that increased salinity decreased total water uptake by the crop, but in most treatments wheat still extracted 40% of its requirement from the groundwater, similar to the proportion reported for non-saline conditions. Yield depression was limited to 30% of maximum when the irrigation water was of relatively good quality (1 and 2 dS/m) even with saline groundwater (up to 6 dS/m). Crop water productivity (grain yield basis) was around 0.35 kg/m 3 over a wide range of salinity conditions when calculated conventionally on the basis of total water use, but was generally above 1.0 kg/m 3 if calculated on the basis of irrigation input only.

The Suitability of Controlled Drainage and Subirrigation in Paddy Fields

DRAINMOD, an agricultural water management simulation model, was used to investigate the suitability of controlled drainage/subirrigation scenarios in 52 ha of northern Iran paddy fields which planted in April to September and the rest of the time being waterlogged and pounded and could not be cultivated because of high water table, low permeable top soils and unsuitable drainage systems. The model as run for 30 year climate data. Various drain depth and spacing combinations and different weir setting were simulated. Simulation results showed that the xcess soil moisture was the main factor for yield reduction and the best conditions of controlled drainage and subirrigation were obtained when the depth of weir setting was the same as drain depth and these systems acted as conventional drains. Based on results, controlled drainage and subirrigation were not suitable because of high rainfall in the region. But the conventional controlled drainage system can be used for these fields, so that in wet season the system acts like a conventional or free drainage system and in paddy rice growth periods, it operates as controlled drainage by installing a weir setting outlet drain.

Hydrochemical Effects of Surface Liming, Controlled Drainage and Lime-Filter Drainage on Boreal Acid Sulfate Soils

On the coastal plains of Finland there are approximately 3,000 km2 of acid sulfate soils developed as a result of intensive agricultural drainage of waterlogged sulfide-bearing sediments. The runoff from these soils contains very high amounts of acidity and metals that have severely deteriorated the aquaculture in several downstream rivers and estuaries. Therefore, there is an urgent need to develop and test more environmental friendly ways of draining landscapes underlain with these nasty soils. In this study, over a 3-year monitoring period the effect of excess surface liming, controlled drainage and lime filter drainage of acid sulfate soils on runoff water quality (pH, sulfate, metals) was determined and assessed. The results showed that (1) the liming measures had not prevented severely acidic and metal-rich waters from forming and discharging from the soils, (2) the controlled drainage system might have reduced discharge peaks but its potential effects on the discharged water quality were nondetectable due to its small effect on the groundwater level and naturally inherited heterogeneities, and (3) the spatial and temporal variations identified for the various hydrochemical determinants were not caused by the kind of treatment applied. Therefore, on acid sulfate soil fields, like the one studied here, the short-term hydrochemical effects of the treatments tested are minor (or nonexistent) at least as long as the controlled drainage systems are not technically improved or better maintained.

The effects of controlled drainage on subsurface outflow from level agricultural fields

AbstractDaily outflow frequencies and recession curves were used to identify differences in storage–outflow relationships between two different drainage systems, conventional and controlled drainage. A three‐year (1996–1999) field drainage experiment was carried out on a loamy sand soil in southern Sweden. Plots with an area of 0·2 hectares were drained by conventional subsurface drainage (CD) or by controlled drainage (CWT1 and CWT2). The controlled drainage system allowed the groundwater level in the soil to be varied during the year. It was kept at least 70 cm below the soil surface during the growing season but allowed to rise to a maximum of 20 cm below the soil surface during the rest of the year. Measurements were performed to record precipitation, drain outflow and groundwater levels. Daily values of outflow were divided into 10 categories, based on the size of outflow. Recession curves of hourly measurement of outflow were selected. They behaved like single reservoirs and a linear storage–outflow model was applied. Least squares estimates of the parameters initial outflow, initial storage volume and retention constant were calculated.Controlled drainage had a significant effect on total drain outflow and outflow pattern during the three years of measurement. The total drain outflow was 70% to 90% smaller in CWT than in CD. The analysis revealed that the initial outflows were higher, the retention constant and the temporary storage lower in CWT. The hydrological impacts of the reduction in temporary storage were higher peak flow, shorter lag time and shorter recession time and these effects increased with an increased groundwater level. Copyright © 2003 John Wiley & Sons, Ltd.

Effect of controlled drainage and tillage on soil structure and tile drainage nitrate loss at the field scale

Conservation tillage has become an attractive form of agricultural management practices for corn and soybean production on heavy textured soil in southern Ontario because of the potential for improving soil quality. A controlled drainage system combined with conservation tillage practices has also been reported to improve water quality. In Southwestern Ontario, field scale on farm demonstration sites were established in a paired watershed (no-tillage vs. conventional tillage) on clay loam soil to study the effect of tillage system on soil structure and water quality. The sites included controlled drainage and free drainage systems to monitor their effect on nitrate loss in the tile drainage water. Soil structure, organic matter content and water storage in the soil profile were improved with no-tillage (NT) compared to conventional tillage (CT). No-tillage also increased earthworm populations. No-tillage was found to have higher tile drainage volume and nitrate loss which were attributed to an increase in soil macropores from earthworm activity. The controlled drainage system (CD) reduced nitrate loss in tile drainage water by 14% on CT site and 25.5% on NT site compared to the corresponding free drainage system (DR) from May, 1995 to April 30, 1997. No-tillage farming practices are definitely enhanced by using a controlled drainage system for preventing excessive nitrate leaching through tile drainage. Average soybean yields for CT site were about 12 to 14% greater than the NT site in 1995 and 1996. However, drainage systems had very little effect on soybean yields in 1995 and 1996 due to extremely dry growing seasons.

Effect of controlled drainage and tillage on soil structure and tile drainage nitrate loss at the field scale

Conservation tillage has become an attractive form of agricultural management practices for corn and soybean production on heavy textured soil in southern Ontario because of the potential for improving soil quality. A controlled drainage system combined with conservation tillage practices has also been reported to improve water quality. In Southwestern Ontario, field scale on farm demonstration sites were established in a paired watershed (no-tillage vs. conventional tillage) on clay loam soil to study the effect of tillage system on soil structure and water quality. The sites included controlled drainage and free drainage systems to monitor their effect on nitrate loss in the tile drainage water.Soil structure, organic matter content and water storage in the soil profile were improved with no-tillage (NT) compared to conventional tillage (CT). No-tillage also increased earthworm populations. No-tillage was found to have higher tile drainage volume and nitrate loss which were attributed to an increase in soil macropores from earthworm activity. The controlled drainage system (CD) reduced nitrate loss in tile drainage water by 14% on CT site and 25.5% on NT site compared to the corresponding free drainage system (DR) from May, 1995 to April 30, 1997. No-tillage fanning practices are definitely enhanced by using a controlled drainage system for preventing excessive nitrate leaching through tile drainage. Average soybean yields for CT site were about 12 to 14% greater than the NT site in 1995 and 1996. However, drainage systems had very little effect on soybean yields in 1995 and 1996 due to extremely dry growing seasons.

Simulation and Evaluation of Water Management Systems for a Pine Plantation Watershed

Abstract Water management on forest watersheds can have off-site impacts on the environment as well as on-site impacts on soil water conditions for plant growth. This study was conducted to evaluate the hydrologic impacts and soil water implications for plant growth of alternative water management practices. The forest watershed system modeled was a loblolly pine (Pinus taeda) plantation in the Coastal Plain of North Carolina. The site is characterized by flat, poorly drained soils (thermic typic umbraquults) which are drained with open ditches 100 m apart. No drainage, free (conventional) drainage, alternative forms of controlled drainage and stocking control were modeled to determine effects on water table position and drainage outflow. Silvicultural systems, including an unthinned and a commercially thinned regime, were modeled. The water management systems were evaluated by criteria quantifying both off-site implications and on-site plant-water relationships. Controlled drainage systems were found to be successful in reducing drainage outflow rates and volumes and improving soil water conditions for tree growth. In addition, hydrologic components were examined over the life of the unthinned and thinned forest stands, from planting to harvest. Stand development and silviculture were shown to have significant effects on the hydrology of the forest. South. J. Appl. For. 16(1):48-56.

Effect of Drainage System Design and Operation on Nitrate Transport

ABSTRACT THE computer simulation model, DRAINMOD, was modified to predict nitrate movement from artificial-ly drained soils with high water tables. Nitrate concentra-tions in surface runoff, subsurface drainage and seepage waters were assumed to be constant and independent of the drainage system design for a corn-soybean rotation on these high water table soils. Total annual nitrate outflow was determined for alternative drainage system designs and operational procedures. The results showed that trafficability and crop protection requirements can be satisfied by several different drainage system designs. For the poorly drained soil considered in this study, there was a three-fold difference in NO3-N outflow among systems that satisfied drainage objectives. The amount of nitrate that leaves the field through drainage waters can be reduced by using controlled drainage during the winter months and during the growing season. However if the controlled drainage systems are not used properly an overall increase in nitrate outflow may result.