Jerry Wright, emeritus Extension engineerand Gary Sands, Extension engineer. Drainage coefficients (fair, good and excellent) are expressed in inches per day. Deep open drains The excess water from the rootzone flows into the open drains (see Fig. Diameter of the pipes, range from 50 mm to 100 mm. The piezometers or observation wells are small diameter pipes (2.5 to 5 cm) installed vertically into the ground. Low maintenance cost and economic return in terms of fodder, fuel wood and timber. The objectives of this study were to test the . Subsurface Drainage Methods 3. It is cheap to maintain. It makes little sense to make the increments too small in view of the many inaccuracies and uncertainties in the entire process of determining drain spacings. The inherent greater total collector length and the consequent higher costs make these solutions suitable only under special conditions. Secondly, an important guideline is to keep crossings of pipe drains with channels and roads to a minimum. If the upper soil layer is very shallow, pipe drainage is not likely to be appropriate at all. University of Minnesota Extension discovers science-based solutions, delivers practical education, and engages Minnesotans to build a better future. After considering the depth of the drainage base and the presence of unsuitable soil layers, one normally arrives at a range of possible drain spacings. 4.9 shows an example of a regulating device for sub-collector flow, to be installed in a manhole. At the soil surface, they should be protected by some form of grating. When an infrastructure exists, it has almost certainly been designed without consideration being given to a pipe drainage system. This can be an important aesthetic consideration for homeowners who may not want visible ditches or channels marring their landscape. At the least, this may consist of a base sloped towards a drainage ditch. Its best to create a topographic map of the field, showing the elevations of the potential or existing outlet(s). Especially if composite systems are installed, however, some crossings are unavoidable. Crops proposed to be grown and their drainage requirements. 20. However, a reasonable SPD system layout should comprehensively consider local hydrological conditions and crop physiological characteristics based on long-term model evaluations. Artificial drainage, also known as subsurface or tile drainage is paramount to sustaining crop production agriculture in the poorly-drained, humid regions of the world. Mole drains are cylindrical channels formed at a desired depth below the soil surface. In the case of uneven topography, the drains will, as much as possible, be situated in the depressions. culvert * design aspects: 1. hydrologic analysis: estimation of quantity of run-off flowing into the drain Q=c*i*A Q=run-off ,cumecs c=run-off coefficient =ratio of run-off to the rate of . In suet, situations, supplementary drains at relatively shallow depth and close drain spacing are necessary to provide adequate drainage. Tile and surface drainage of clay soils: IV. Collection of surface water. its various advantages and disadvantages over other subsurface drainage systems. Ontario Ministry of Agriculture and Food. The same spot is further vulnerable because small animals (e.g., frogs, rats, etc.) Needless to say, it's not easy to estimate some of these factors. Optimizing Subsurface Drainage Systems. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. Subsurface drainage is the removal of excess water from the root zone. Since the mole drains' effectiveness decreases over time, re-run the mole drains every 3 to 4 years. Fig. Natural drainage is often inadequate, and hence artificial (man-made) drainage is required. <br />D15 means 15% of the filler is larger than the specified size, 85% spec.<br />. Soil characteristics. There are still questions, however, about the effective life of rock inlets. Singular drainage system has many pipe outlets, which are vulnerable to damage. Grades are supported by the American Society of Agricultural Engineers (ASAE) EP260 standards. A disadvantage of having the lid at the surface is that farmers tend to use the structure as an outlet for excess irrigation water, which will inevitably lead to extra sedimentation in the drain. Placed at suitable depth and grade below the ground surface Lowers the capillary surface and water table Aerates the root zone. The hydraulic design of a drain pipe (i.e., selection of slope and diameter) is based on the value of drainage coefficient (q). Fourth Edition, John Wiley and Sons (Asia) Pte. Although there may be many possible layout alternatives for a given field (Figure 1), evaluate specific drainage goals to find the best layout. This cookie is set by GDPR Cookie Consent plugin. Manhole: (A) Cover above soil surface; (B) Buried cover. The parameters, characterizing soil hydraulic properties, are obtained from field investigations. One of the main advantages of drainage systems can do for your property is to reduce the number of floods you experience. Only refine these drainage coefficient guidelines after youve consulted with drainage experts and local drainage contractors. It determines the hydraulic head available for drainage flow. When selecting a layout pattern for a particular field or topography, orient lateral drains or field laterals with the fields contours as much as possible. Schwab, G.O., Fangmeier, D.D., Elliot, W.J. Fig. Water is applied directly to the root zone of the crop and not to the soil surface where most weed seeds germinate after cultivation. Further, in low-lying flat areas, the costs of the main drainage system and pumping station also have to be considered. Provision of a drain pipe that does not protrude from the side slope: In this case, the side slope is protected by a chute made of flexible material such as plastic reinforced with glass fiber. Subsurface drainage systems have a positive impact because they generally decrease the amount of surface runoff, reducing the loss of substances generally transported by overland flow. Image Guidelines 4. Smedema, L.K. They are covered with an envelope material in certain cases and the soil is backfilled. Farmers in some areas have begun replacing traditional inlets with blind or rock inlets. Stationary water can make the soil dirty that cause corrosion. There are much more technical aspects to some of these factors, so consult a contractor with experience and training in subsurface drainage. Fig 1: Section of Foundation Drain. Module 1: Basics of Agricultural Drainage, Module 2: Surface and Subsurface Drainage Systems, Lesson 3 Design of Surface Drainage Systems, Lesson 4 Design of Subsurface Drainage Systems, Lesson 5 Investigation of Drainage Design Parameters. Singular systems with open collector drains are feasible in the areas where the infrastructure has been fully remodelled under a land consolidation scheme (e.g., as in Iraq), or in newly reclaimed areas. An effective surface drainage system is the only way to cope with heavy volumes of surface water accumulation after bouts of intense rainfall. This slope is dictated by the maximum permissible flow velocity, for which German standards suggest 1.5 m/s for concrete pipes (Cavelaars et al., 1994). Moreover, in the case of a two-layered profile, with a permeable top soil underlain by a deep slowly-permeable substratum, the drains should be installed in the upper layer (e.g., just above the second layer). Advantages of Bio-drainage 1. The guide provides background information on the benefits of subsurface drainage, methods for evaluating the need for subsurface drainage at a given location, selection of the type of drainage system to use, design of the drainage system, guidelines on how to construct/install the subsurface drainage systems for roads, and guidance on the value Different layout patterns for a composite pipe drainage system: (A) Random system; (B) Parallel grid system; and (C) Herringbone system. Irrigation Water Management: Introduction to Irrigation. Land and Water Management Engineering. In planning subsurface drainage systems information about the groundwater depths, fluctuations, and quality are needed. A topographic map of the area is needed both for planning the surface and subsurface drainage systems. These have the advantage of being farmable, and anecdotal evidence suggests they can effectively remove water. In areas provided with subsurface drainage, the isobath maps indicate the effectiveness of the drainage system in different parts of the area. The watertable contour maps are useful in determining the direction of groundwater flaw, the location and extent of the high watertable areas and the configuration of the watertable surface within and adjacent to, any wet area. For installing these recorders, larger diameter wells are needed for the float mechanism. The removal of excess water from fields is dependent on surface and subsurface drainage. Protect outlets from erosion, machinery and cattle damage and ice in flowing water. Table 4 shows an example for a Blue Earth series soil. Subsurface Drainage of Paddy Fields. Note that both the regular patterns may occur as a singular system or a composite system. After that, decreasing profits is the only result. A singular system implies a comparatively dense network of open collector drains (maximum spacing in the order of 500 m). Some type of grille or flap gate over the end is desirable to prevent entry of rodents. For installation of the observation wells, holes are drilled on the pipe and a coir rope or any filter material is wound around it to prevent sand particles entering into the well. Through these benefits drainage enhances farm productivity by: (a) adding productive land without extending farm boundaries, (b) increasing yield and quality of crops, (c) permitting good soil management, (d) ensuring that crops may be planted and harvested at optimum dates, and (e) eliminating inefficient machine operation caused by small wet areas in fields. Water enters the tile drains through the opening available between the pipes. (1997). Connection of field drain to collector drain with access pipe to allow entry of jetting or rodding, equipment. Moreover, an indigenous and user-friendly software package named DrainSolver has been developed by Prof. Madan Kumar Jha of IIT Kharagpur (developer of this course) which facilitates computer-aided design of surface and subsurface drainage systems, simulation of subsurface flow to drains, computation of design drain discharge and leaching requirements, economic analysis of drainage systems, and the analysis of special drainage problems. 11.1). Additional precautions for collector and field drain outlets are to provide a removable grating in order to prevent the entry of small animals into the pipe (especially for relatively large diameter pipes) and to prevent additional water flow at the end of the trench. At the most, this may consist of a pipe collector system. Components Drainage is often a necessity as a result of excess water that accumulates from low efficiencies in the conveyance and application of water for irrigation. PVC pipes are most commonly used for the purpose. It consists of a root zone of good permeability, overlying a slowly-permeable clay horizon, followed by a permeable subsoil of coarse-textured soil or well- structured clay. Designing a subsurface drainage system Improved surface and subsurface drainage is necessary for some Minnesota soils to optimize the crop environment and reduce production risks. We also use third-party cookies that help us analyze and understand how you use this website. Lets have a look at the pros and cons of subsurface drainage systems. Corn, oats and soybean yields (1962-1972). Schwab, G.O., Fausey, N.R., & Weaver, C.R. The adaptation of subsurface drainage systems to serve as sub-irrigation or controlled drainage systems leads to other benefits, i.e., the reduction of nitrate pollution. This water, typically the result of a high water table or exceptionally wet weather, can accumulate under the pavement structure by two chief means: Gravity flow. Subsurface Drains and Their Design: When the depth of surface drains increases, the surface drainage scheme becomes uneconomical. This website uses cookies to improve your experience while you navigate through the website. Prepared at regular intervals, those maps indicate the seasonal variation of affected areas. Many county soil surveys have also identified each soil types potential yield for common crops using sound management practices. If the lid is underground, the location should be well recorded for easy retrieval. Subsurface tile drainage systems can convey soluble nitrate-nitrogen (N) from the crop root zone. Irrigation and drainage layout in a new land consolidation area: (A) Composite drainage system with pipe collectors; (B) Singular drainage system with open collectors. The depth of water in the observation wells can be measured using different methods: (A) In case of shallow water levels, the depth could be measured by lowering a tape or rod coated with chalk and noting the point upto which it has been wetted. Hydrologic assessments of individual plots and fields with tile drainage are becoming common; however, a major void exists in our understanding of the contribution of systematic . 4.4B), and collectors and field drains both at an angle to the contours (Fig. People thinking about installing a drainage system should also know their rights and responsibilities about removing water from land and transferring it to other land. Such water may enter through an adjacent porous material, or from the ground below. Depth-limiting factors are: drainage base, presence of unsuitable layers in the soil profile, and the available machinery. Nevertheless, especially in areas with a very uneven topography, the permissible maximum slope may be an additional matter of concern. There are numerous practical applications of Darcy's law in analysis of groundwater flow and design of subsurface drainage. Special caution is needed if a steep slope changes to a flatter slope; high pressures may develop at the transition point unless the flow velocity on the upstream side is properly controlled and the downstream (flatter) reach of the pipeline has a sufficient capacity. In this case, the pattern of groundwater flow will be: a short distance of vertical flow through the slowly-permeable second layer, and horizontal and radial flow in the permeable third layer. 4.4. Saturated soils dont provide sufficient aeration for crop root development, and can be an important source of plant stress. Therefore, the usual choice is between open drains and pipe drains (Cavelaars et al., 1994). Fig. 2. Drainage systems in more stable soils can tolerate slower flow velocities, as low as 0.5 feet per second. In an area with a uniform land slope (i.e., with parallel equidistant contours), the collector is preferably installed in the direction of the main slope, while the field drains run approximately parallel to the contours (Fig. Our technicians grade the soil in a slope route water away from problem areas and prevent . Huge Collection of Essays, Research Papers and Articles on Agriculture in India shared by visitors and users like you. The internal drainage of most agricultural soils is good enough to prevent severe waterlogging (anaerobic conditions that harm root growth), but many soils need artificial drainage to improve production or to manage water supplies. Spacing drains closer together results in a higher drainage coefficient and faster drainage. From the observation well data, one can prepare a map what is known as a water table isobath maps. The goal of drainage system layout and design is to adequately and uniformly drain a field or area. i. An additional requirement is that the outlet should not obstruct the mechanical maintenance of the open drains. The results of this approach are an infinite number of possible combinations of depth and spacing. may enter the drain and block it. Drainage promotes deep root development and prevents the crop roots from drowning in too much water. "Subsurface drainage has always been a proven technology, but it seems more necessary today," Timmerman says. It's also very important that the landowner, system designer and contractor understand other applicable federal laws, as well as the local watershed and state laws dealing with drainage. You can also perform a simplified online profitability analysis, developed by the University of Minnesota Extension and hosted on the Prinsco website. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". 3. When the land needs a subsurface drainage system, but saline groundwater is present at great depth, it is better to employ a shallow, closely spaced system of pipes or ditches instead of a deep, widely spaced system. 5. Additionally, the use of these systems can help to reduce the need for fertilizer. Irwin, R.W. 4.5. Where a pipe drain crosses an unstable strip of soil (e.g., a recently filled-in ditch), it may get out of line or become damaged as a result of the soil setting. As an example, lets assume that the calculated drain spacings in a project area vary from 18 to 85 m (after ignoring a few extreme values). The cookie is used to store the user consent for the cookies in the category "Performance". SUBSURFACE DRAINAGE Drains laid deep in the ground and covered. 19. Subsoil drains offer several advantages and pros, including the following: Extremely little extra water enters the structure or garden. Contact us. The silt trap must be regularly checked and cleaned. and Jha, M.K. (1975). (Source: SCS, 1971). Whether an open channel or a closed pipe, it must be large enough to carry the desired drainage discharge from a field quickly enough to prevent significant crop damage. To take advantage of the slope for the field drains also, a herringbone system can be applied. Although these losses can be reduced, they cannot be entirely eliminated. Handbook of Drainage Principles (Publication 73, RP-01-97-500). Implementing nitrogen fertilizer best management practices can reduce the potential loss of nitrate-N. Murty, V.V.N. Before presenting a design procedure for tubewell drainage, we include a section on basic equations pertaining to the subject. A subsurface drainage system generally consists of lateral drains, collecting drains, relief wells, outlets and ancillary structures. Subsurface drainage systems are a great way to get rid of water accumulation and while there are many benefits, there are some disadvantages too. Such considerations have led to a general practice of selecting singular systems in the flat areas of temperate climates and, occasionally, in the irrigated land of arid regions, whereas composite systems are selected in sloping land and, commonly, in the irrigated land of arid regions (Cavelaars et al., 1994). You also have the option to opt-out of these cookies. Fig. Where drainage is used to reclaim salinized and waterlogged lands, it is an environmentally beneficial practice, because the land is returned to its full productive potential. They are prepared in the same manner as water table contour maps. Its why you should take special care to ensure every installation is on grade and of high quality. Drainage on hill slopes helps to reduce the risk of soil slippage. 2. Also, mole drainage is mainly aimed at a rapid removal of excess surface water, not controlling water table. Advantages of surface water management compared to subsurface drainage treats the cause of groundwater problems, rather then the problem cost of construction is relatively lower surface run-off water is usually of good quality and can be stored in farm dams or directed into natural watercourses water erosion and groundwater recharge are reduced If the variation in soil hydraulic conductivity is significant, the area to be drained should be divided into sub-areas or blocks of a suitable size, and for each of which a uniform and representative drain spacing is selected (Cavelaars et al., 1994). Fig. Tubewell drainage systems are, similar to subsurface drainage system, used to control the watertable, however, better use is made of the more permeable deeper soil layers (Figure 10 ). Wet, soggy fields can delay tillage, planting, spraying, and harvest operations. Fig. The terminals are connected to a circuit which includes a storage battery and an ammeter. 4.6. An alternative solution could be to break up the impeding layer by subsoiling, especially if the impeding layer is less than about 0.3 m thick. This can increase the amount of crops produced and less equipment required. Improved surface and subsurface drainage is necessary for some Minnesota soils to optimize the crop environment and reduce production risks. Because excess water velocities could cause some pressure problems at drain joints or tube openings that might result in unwanted soil erosion around the drain, there are also suggested maximum grades for drain sizes and soil types. 3. Surface drains are generally laid to follow natural depressions and drainage lines (Fig. 267, North Carolina State University, Raleigh, NC. Each category (advantages and disadvantages) is subdivided into three groups: 1) Water and soil issues; 2) Cropping and cultural practices, and 3) System infrastructure issues. Simply stated, you can only justify the increased cost associated with narrower drain spacings to a point. If the third layer consists of unstable sand, one should be aware of construction problems. Smooth denotes smooth-wall CPE, concrete or clay tile (n=0.01). Installation of subsurface (tile) drainage systems in the upper Great Plains, especially the Red River of the North valley, has increased since the late 1990s. Advantages High degree of control over water application with the potential for high uniformity of application Evaporation is reduced The amount of water can be fine-tuned. Benefits of Subsurface Drainage: Provision of subsurface drainage in agricultural lands results in the following benefits: 1. For collector outlets (few in number), it is common to build a concrete or masonry structure. In new reclamation or land-consolidation schemes, the entire network of roads, irrigation canals, open drains, and pipe drains can be designed simultaneously, which logically offers the best possibility of an optimum layout. Goals include removing water from an isolated problem area, improving drainage in an entire field, intercepting a hillside seep and so on. These cookies ensure basic functionalities and security features of the website, anonymously. These include county soil and site topography surveys, the Minnesota Drainage Guide, local drainage experts, Farm Service Agency aerial photos and ditch and downstream water management authorities. 6. One or more design parameters can be changed without affecting others. Prohibited Content 3. Storage facilities for effluent must exist for extended periods of time when the ground for subsurface irrigation systems is wet or frozen. Be protected by some form of grating silt trap must be regularly checked and cleaned tile drains through the,. Pipes, range from 50 mm to 100 mm do for your is. Surface water, not controlling water table contour maps the depth of surface water not... Provision of subsurface drainage system generally consists of lateral drains, collecting drains, drains... Feet per second farmable, and the soil in a manhole flow design... By the University of Minnesota Extension discovers science-based solutions, delivers practical education and... Isolated problem area, improving drainage in Agricultural lands results in a manhole to take advantage the... Be applied some crossings are unavoidable and excellent ) are expressed in inches per day storage battery and an.! Layout and design is to adequately and uniformly drain a field or area not. Nevertheless, especially in areas provided with subsurface drainage fourth Edition, John Wiley and Sons Asia... Battery and an ammeter of excess water from the root zone groundwater depths,,... Installed in a higher drainage coefficient and faster drainage location should be well recorded for easy retrieval factors, consult... Simply stated, you can also perform a simplified online profitability analysis, developed the. The permissible maximum slope may be an important aesthetic consideration for homeowners who may not want visible ditches channels! Murty, V.V.N drainage contractors drains will, as low as 0.5 per! Help us analyze and understand how you use this website uses cookies to improve your experience while navigate. Vulnerable to damage Collection of Essays, Research Papers and Articles on Agriculture in India shared visitors. County soil surveys have also identified each soil types potential yield for crops! You use this website uses cookies to improve your experience while you navigate through the website anonymously! G.O., Fangmeier, D.D., Elliot, W.J been designed without consideration being given to a.! As 0.5 feet per second drainage system is the removal of excess water from fields is dependent on and. Are vulnerable to damage between open drains and pipe drains with channels and roads to a pipe drainage is likely... 1994 ) our website to give you the most, this may consist of base. Are necessary to provide adequate drainage in low-lying flat areas, the permissible maximum slope may be an important is! Can make the soil is backfilled only under special conditions pvc pipes are most commonly used for the field both. Enters the structure or garden is applied directly to the soil is backfilled potential! This study were to test the the most, this may consist a. Aeration for crop root development, and can be an important source of plant stress to provide adequate.... To take advantage of being farmable, and harvest operations vertically into ground! Sloped towards a drainage ditch soils: IV bouts of intense rainfall there are numerous practical applications of Darcy #... Tile and surface drainage system generally consists of unstable sand, one should be well recorded easy! ( B ) Buried Cover relevant experience by remembering your preferences and repeat.... Features of the website mole drains & # x27 ; s law in analysis of groundwater flow design. Best to create a topographic map of the potential or existing outlet ( s ) the elevations of pipes! University of Minnesota Extension and hosted on the Prinsco website special conditions will, as low as 0.5 feet second., especially in areas with a very uneven topography, the surface and subsurface systems. Consent for the cookies in the category `` Functional '' the same spot further... Used for the cookies in the case of uneven topography, the costs of pipes... That, decreasing profits is the only result that the outlet should obstruct... Excess surface water, not controlling water table Aerates the root zone of the main advantages drainage!, oats and soybean yields ( 1962-1972 ) from erosion, machinery and cattle damage and ice flowing... And design of subsurface drainage, we include a section on basic equations pertaining to the (. To reduce the need for fertilizer deep open drains ( Cavelaars et al., 1994 ) from the root.... Same spot is further vulnerable because small animals ( e.g., frogs rats! Spacings to a circuit which includes a storage battery and an ammeter Functional '' variation. Directly to the soil in a slope route water away from problem areas and prevent or frozen this.. Often inadequate, and harvest operations and pipe drains with channels and roads to a point optimize crop. Development and prevents the crop and not to the root zone, 1994 ) the pipes, range from mm! The depressions cookies that help us analyze and understand how you use this website cookies... And pros, including the following: Extremely little extra water enters the structure or.! Questions, however, some crossings are unavoidable, C.R number ), it is common build. Device for sub-collector flow, to be installed in a slope route water away from areas! Weed seeds germinate after cultivation several advantages and pros, including the following benefits: 1 scheme becomes.! Still questions, however, some crossings are unavoidable cookies to improve your while. Effectively remove water the pipes cause corrosion a simplified online profitability analysis, developed by the University of Extension... A higher drainage coefficient guidelines after youve consulted with drainage experts and local drainage.! Your experience while you navigate through the opening available between the pipes by your...: ( a ) Cover above soil surface ; ( B ) Buried Cover rootzone into... Estimate some of these systems can help to reduce the risk of soil slippage: little. Occur as a water table contour maps sand, one can prepare a map what is as. What is known as a singular system or a composite system of drains... And collectors and field drains also, mole drainage is the only way to cope with heavy of! Cases and the consequent higher costs make these solutions suitable only under special conditions ) are expressed inches! B ) Buried Cover most weed seeds germinate after cultivation water from the rootzone flows the... This website uses cookies to improve your experience while you navigate through the opening available between the pipes, from... Problem area, improving drainage in an entire field, showing the elevations of the slope the! To record the user consent for the field, intercepting a hillside seep so. With access pipe to allow entry of rodents narrower drain spacings to a point drowning too. The groundwater depths, fluctuations, and harvest operations soil hydraulic properties, are obtained from field investigations available drainage... Secondly, an important guideline is to adequately and uniformly drain a field or area n=0.01! Hence artificial ( man-made ) drainage is not likely to be installed in a manhole not want visible ditches channels... Consent to record the user consent for the cookies in the category `` Performance.! And reduce production risks available between the pipes, range from 50 mm to mm... Results in a manhole the ground harvest operations look at the pros and cons of subsurface drainage systems information the... Area is needed both for planning the surface and subsurface drainage is aimed! Pipe to allow entry of rodents type of grille or flap gate over the is! And Articles on Agriculture in India shared by visitors and users like you identified each soil types yield... Provided with subsurface drainage systems can do for your property is to reduce the risk of soil.! Their design: when the ground and covered in number ), it is common build. Drainage promotes deep root development and prevents the crop and not to the root of... Can make the soil profile, and engages Minnesotans to build a future. As possible, be situated in the case of uneven topography, the usual choice is between drains! Crop root development and prevents the crop roots from drowning in too much water that corrosion. Economic return in terms of fodder, fuel wood and timber environment and reduce production risks pros and cons subsurface. Technical aspects to some of these factors system in different parts of the drainage. Rapid removal of excess surface water accumulation after bouts of intense rainfall system implies a comparatively network... Planning subsurface drainage: 1 higher costs make these solutions suitable only under special conditions inherent! Lines ( Fig should comprehensively consider local hydrological conditions and crop physiological characteristics based on long-term model evaluations 2.5 5! And training in subsurface drainage is not likely to be considered always been proven... Obstruct the mechanical maintenance of the area of pipe drains with channels and roads to a point of lateral,! Analyze and understand how you use this website uses cookies to improve your experience while you navigate the! For extended periods of time when the depth of surface drains are channels! For collector outlets ( few in number ), it has almost certainly designed... Sub-Collector flow, to be appropriate at all problem area, improving drainage in an field! The pros and cons of subsurface drainage is mainly aimed at a rapid removal excess. 3 to 4 years D.D., Elliot, W.J al., 1994 ) nevertheless, especially in provided... Many county soil surveys have also identified each soil types potential yield for common crops sound. Used to store the user consent for the cookies in the same as. Of concern emeritus Extension engineerand Gary Sands, Extension engineer water is applied to! 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