Drainage of swampy areas. Peatlands: goals and consequences of drainage, methods of flooding

If the purchased suburban area is located on a peat bog, its owners will have to perform a number of works to improve the soil on it. The land in such places, unfortunately, cannot be considered too suitable for growing various kinds of crops. The soil in peatlands contains very little oxygen, which replaces methane. Also, such areas in spring and autumn turn into a real swamp due to flooding. How to drain the peat allotment if necessary - we will talk about this later in the article.

Ways to improve

In some cases, it is possible to solve the problem of swampiness of the allotment very in a simple way- by adding a certain amount of land imported from outside. But, of course, it is possible to use such a technique only when water is collected at the site due to the fact that it is located in a lowland and has relatively small size. In all other cases, water has to be diverted from the dressing.

The answer to the question of how to drain the site, in this case, can be two technologies:

superficial;

with piping.

The first method is considered the easiest. Open drainage in a wetland with your own hands will be absolutely easy to do. But when using pipes, you can equip a more efficient drainage system.

Diversion with ditches

This method is a good answer to the question of how to drain a swamp on a peat bog. The advantage of this method, among other things, is that when it is used, the owners will not have to spend a penny to drain water from the site. For drainage, in this case, a ditch about 50 cm wide and at least 1 m deep is dug along the edge of the allotment on the side that is located below the others.

If there is a slightly higher, also swampy neighboring area nearby, a trench should also be made on the border with it. This will close access to water from someone else's allotment.

Subsequently, in the process of execution on the site, various kinds of channels will need to be filled with all kinds of construction and garden waste. It can be, for example, stones, broken bricks, weeds, etc.

Benefits of using pipes

open way drainage of water through ditches is simple and cheap. However, this technique is used only in not very wetlands. In all other cases, it is advisable to equip allotments with full-fledged drainage systems using perforated pipes.

The answer to the question of how to drain the swamp in the garden, such technology in most cases is just perfect. The advantages of such outlet networks, among other things, include:

more uniform and faster regulation of the water balance in the soil;

the ability to cover the entire area of the site.

When using such sleeves pass underground. Due to this, the usable area of the site is not reduced. Growing beds horticultural crops on such an allotment it will be possible to do it, including directly above the pipes.

How to set up a closed system

In this case, ditches are also dug on the site to drain water. In this case, the main trench is located along the perimeter of the allotment. Next, ditches are dug over the area of \u200b\u200bthe site.

When using this method of drainage, a waterproofing agent is laid at the bottom of the dug trenches - a thick film or roofing material. Next, a layer of medium-sized rubble or pebbles is poured into the ditches. Perforated pipes are laid on top. In order to prevent the holes of such drainage lines from becoming clogged in the future, they are pre-wrapped with geotextiles.

Pipes are connected at the points of convergence or intersection of ditches using tees or fittings-corners. Above these network elements, manholes made of plastic or concrete are necessarily equipped. If there are such additions in the system, in the future it will be very easy to eliminate blockages that appear in the highways and clean them from accumulating sludge.

What you need to know

Of course, in order for the water to subsequently leave the section through the pipes by gravity, they must be laid at a slope. Otherwise, it will not work to dry the dressing. Unfortunately, it is impossible to mount the drainage network lines under too great a slope. In this case, the pipes will subsequently silt up very quickly. Very small slope drainage channels also not worth doing. Otherwise, the system will subsequently work inefficiently.

In most cases, when arranging garden sewage networks, pipes are laid at an angle of 0.5 to 3 cm per running meter. It is not worth deviating from these parameters up or down.

receiving well

How to drain the area with pipes, we thus found out. But where can you put the excess water itself? You can drain it from the site, if it is located on the outskirts, simply beyond its aisles - into some ravine, stream or pond. But if neighboring plots are located next to the swampy garden, a special well will have to be equipped to receive wastewater. If desired, such a container can also be built on a site located on the outskirts. After all, the water collected during drainage can later be used to irrigate the same beds.

Receiving wells are being equipped at the lowest point of the suburban area using the following technology:

a hole is dug in the ground, into which the main drainage trench is inserted;

the bottom and walls of the pit are concreted with a layer of 5-10 cm.

Of course, in the concrete structures of the well, when pouring, holes should be provided for the installation of pipes.

Instead of concrete structure, when arranging the drainage system, you can also use plastic. It will be easy to purchase such a capacity from companies specializing in the supply of equipment for drain systems.

receiving pond

In most cases, the owners of vegetable gardens on peat bogs, of course, equip a well to drain water. But instead of it, if desired, you can make an artificial reservoir on the site - beautiful decorative pond. In this case, a foundation pit is also dug in the ground, but wider.

The bottom and walls of the pit for arrangement on the site of an artificial reservoir are thoroughly cleaned of roots and stones. Further, the pit is laid out with a strong waterproofing material- best with a thick film. Through the holes in the film into the pond are displayed drainage pipes. You can disguise them at the bottom, for example, with beautiful stones or some aquatic plants. In summer, it will be possible to release even unpretentious fish from the aquarium into this reservoir. Spectacular marsh plants are usually planted around the pond.

Main difficulty

In principle, as you can see, the answer to the question of how to drain the area from water with your own hands is quite simple. most challenging task in this case, most likely to become physically difficult excavation. After all, there are actually a lot of ditches on the site. However, in order for such a system to work as efficiently as possible, trenches on the site, of course, should be laid first of all in the right places.

It is best, of course, to entrust the project of arranging the drainage system of a wetland allotment to a specialist. A professional will be able to take into account all the nuances of the relief of a particular area. However, projects of drainage systems in suburban areas are, unfortunately, quite expensive. If there is no money to order a pipe laying plan, you can try to develop it yourself. In order to find out where it is best to dig drainage trenches, you will have to wait for the first heavy rain. Observing the streams flowing down the ground, it will be possible to accurately determine the optimal location of the trenches.

How to drain a swamp: using moisture-loving plants

Of course, in most cases, it is possible to drain a wetland only in cardinal ways- arranging ditches or laying pipes. But as additional measure in such a garden it is also worth planting plants that draw a lot of water from the ground. It can be, for example, willows, birches or maples. Such trees, since they have a significant height, are planted, of course, usually on the north side of the allotment. Otherwise, in the future, they will block plantings, which, in turn, can easily lead to a decrease in the yield of horticultural and horticultural crops.

The high level of groundwater in the area can also be reduced with the help of shrubs. For example, a lot of water from the soil can be taken by hawthorn, wild rose, vesicle, irga. Such plants can be planted around the perimeter of the site to create a hedge.

Methane in soil

Of course, after draining by open drainage or by laying pipes, the land on the site will, in any case, become more suitable for growing garden and horticultural crops in terms of composition. But in order to further improve its quality, site owners will have to:

scatter a mixture of clay and sand over the site with a thin layer;

carefully dig the allotment using a shovel or, preferably, a motor cultivator.

Of course, a very good solution would be to scatter around the site, in addition to clay and sand, before digging, also manure mixed with sawdust. This will not only improve the structure of the soil, but also make it more fertile and nutritious. Incorporation into the soil of various kinds mineral fertilizers also make it more suitable for growing horticultural and garden plants.

Advantages of peatlands

So, we figured out how to drain the area from water with our own hands and improve the soil on it. Such an allotment can, of course, cause a lot of trouble for its owner. However, peatlands, in comparison with other types of soils, have their own advantages. For example, in such areas, plants usually tolerate winters much better. The earth on peat bogs is frozen slowly, in thin layers. At the same time, the soil on such allotments never freezes too deep. So on such an allotment, after it has been drained, you can plant, for example, heat-loving roses, apricots, etc.

There are many negative aspects that the summer resident has to face. Either the land is not fertile and the plants do not want to grow, then the summer drought destroys the entire crop, then pests and diseases do not give rest.

For someone, the site is a steep slope and it takes a lot of time and effort to turn it into a convenient and beautiful place. Another important issue is flooding.

Only by carrying out activities aimed at draining suburban area, you can get rid of this trouble. Today we will consider what needs to be done for this in order to forget about excess moisture for a long time.

How to dry the area with your own hands? Basic ways

The degree of swamping of the site is different and may be due to various factors. For example, there is such a case when excessive moisture in more due to topography and soil type. Those. water cannot leave the site along a natural slope. Then it is necessary to create this slope artificially by planning the territory. If necessary, bring up the earth, fill in the recesses.

It happens that water stands only because you have heavy clay soil. In this case, if it is not possible to make a backfill, you need to arrange drainage. With it, you can drain the swamp on the site. To do work on laying the drainage system, you will need some knowledge, competent calculation, accurate planning.

There are many companies that, for a fee, will perform not only the calculation, but also all earthen and installation work. An alternative option is to do everything yourself, having previously studied all the necessary information.

Moreover, water from the drainage system can flow into the reservoir, which is arranged at the lowest point of the cottage. The purpose of the reservoir can be anything: for irrigation, a decorative structure with plants, etc.

Almost all methods of draining a garden plot are to divert water from the territory.. It’s just fine if the water has somewhere to leave the site, but it happens that the cottage is located lower in relation to the surrounding area, or there are some structures (buildings, fences, etc.) in the way of the running water. In this case, water must be collected centrally. This can usually be done by constructing a system of channels and ditches.

It should be understood that water must also leave the ditch, which is determined on the spot, depending on the location of neighboring sections. Dig it in the lowest place.

If the site is more or less flat and has a clearly directed slope, then the ditch is placed along the fence in a low place, and it should have a width of about 50 cm and a depth of at least 1 m, a length of 2-3 m.

Then, during the year, the ditch must be gradually filled with various construction and other solid waste (broken bricks, stones, broken glass). It is laid quite tightly, and when the ditch is filled to the bottom fertile land, nearby they dig a similar ditch, which will be a continuation of the old one.

The removed vegetable soil from the new ditch is laid in the old one. By doing so, you will get a good drainage system around the perimeter of the site. You may have a question, why make a ditch (drainage) in the highest place? You don’t have to, but if another one located above adjoins your site on this side, then there is a sense in such a closed ditch, because it will intercept water from its neighbors, preventing it from flowing through the entire cottage.

As you can see, in order to properly drain the wetland, you need to combine several methods. This includes backfilling, drainage, and the construction of ditches and canals. Another additional way, which is called biological, is to use moisture-loving plants which will absorb some of the moisture.

What plants can be used to drain the site?

Since the water in the wetlands is high, most plants will do poorly, especially those that have a tap root. root system. The roots of such plants are located deep in the ground and under the influence of excessive moisture and lack of oxygen, they begin to rot.

You can plant such moisture-loving and well-known trees as willow, birch, maple. There are many beautiful forms and varieties of these plants, so they will not only absorb excess moisture, but will also become beautiful decoration your garden.

From conifers, you can plant spruce, whose roots are located close to the surface, but it is better to play it safe and plant them on small mounds. The device around the perimeter of the hedge of wild rose, hawthorn, spirea, shadberry, vesicle will help to drain the site.

Alder and poplar also grow well "in the water", however, you are unlikely to want to have them on your site due to their low decorative value. In addition, poplar fluff causes allergies.

You can also plant hydrangea, mock orange, but if the site is very swampy, it is better to abandon these plants. Amur lilac also withstands temporary flooding.

Fruit trees grow very poorly on waterlogged soils. Therefore, when buying, choose varieties whose stock has a superficially located root system. And it is better to plant them on specially arranged mounds about 50 cm high (in some cases - 1 m). Of the berry bushes, blackcurrant feels good. From herbaceous plants dehumidifiers are perennial asters, marsh iris, aquilegia and others.

Excessive moisture has a bad effect on the condition of the soil, it becomes acidic. Therefore, any drainage also includes liming, which will help increase the fertility of the soil.

In general, draining the land with your own hands is not easy, but everyone can do it. It will take a lot of time and effort, but the result is worth the effort, because in the end - you do everything only for yourself and your family.

As a result climate change or rising groundwater levels, flooding or waterlogging occurs land plot. There are several methods on how to drain a swamp in a summer cottage. As a result of such work, in a very small area, the violation of the ecological balance is reduced to zero, so the question of whether it is necessary to drain the swamp on your site is not worth it.

Those arguments why it is impossible to drain the swamps do not stand up to scrutiny. On your land, this is simply necessary. Of course, this is a laborious and costly process, but nothing is impossible. The work begins with geological and geodetic studies of the soil, which will give an opinion on the causes of waterlogging, methods of drainage and whether it is necessary to drain the swamp in this particular place.

Methods for draining a wetland

Effective drainage system will allow you to remove excess water from the land and set the required level of moisture for successful farming. There are three main methods of dewatering a site, and each of them has its own advantages and disadvantages.

The open method consists in laying network channels along the site. Ordinary and gross channels are interconnected and looped on the main channel. The central main canal plays the main role of a drainage system and leads to a water intake outside the site.
The closed method consists in laying a drainage system. Such work requires proper planning and ramping; for the drainage system, cast iron, asbestos or plastic pipes. now producing plastic corrugated pipes with geotextile winding different diameter.
The combined method combines the first two and is very popular in summer cottages. Waterlogging can be facilitated by dense clay soils. In such cases, it is possible to sample the heavy soil down to the water table and make a bulk area of loose soil of a suitable composition.
There are other non-standard methods for solving this problem. You can completely choose heavy soil and fill the place with fertile soil. If you are not interested Agriculture, then by deepening the wetland, you can create an artificial lake.

Preparatory work and open method of draining the wetland

What method of draining the swamp is suitable for your site can only be said after finding out the causes of waterlogging. For this, a study of the site in the swamp is carried out. Soil samples are taken, the level of groundwater, the direction of flow along the soil layers and the lowest point of the relief are established.

As a result of surveys by the geological and geodetic service, you should get a three-dimensional plan of the site and have a clear idea of the direction of movement and depth groundwater. Outside the wetland, determine a location for a drainage well. It should be located at the lowest point and of sufficient depth.
For the middle section, a well with a diameter of about a meter is suitable. It digs or drills down to groundwater. The bottom is covered with rubble, with a thickness of 30 cm to half a meter. Walls can be strengthened brickwork or stacked concrete pipes of the appropriate diameter. It is also possible to equip an artificial reservoir in the lowest current of the summer cottage, and collected water use for irrigation.
From the well, draw a straight line to the highest point of the land. The main trench for water flow will run along it. For a moderately swampy area, a trench 50x75 cm can be suitable, the bottom of which is covered 5–10 cm with a mixture of sand and gravel and is well rammed. The walls of the trench can also be reinforced with brickwork or pick up improvised materials. For example: cutting boards, sheet metal or slate and fix them along the walls of the trench with stakes. The slope from the top of the trench to the bottom - the place where the drainage trench drains into the well should be 25 ° - 30 °.
Perpendicular ditches make less deep and do not particularly strengthen. Depending on the state of swampiness, they can be deepened, expanded and new ones added. All side ditches converge to the central trench at a slope. The less water in the area, the more difficult it is for her to leave. Therefore, ditches must be periodically cleaned and deepened.

Hidden drainage systems for draining swampy soil

Drains are special pipes for draining a swampy land. Up to 50% of the top of the pipe is covered with holes for water to enter. Openings are equipped with mesh filters, or winding with geotextile fabric is made to prevent backfilling and clogging of drainage pipes.

Pipes are used in different diameters and materials. Of the novelties, there are corrugated pipes that have the ability to conform to relief contours and have smooth inner surfaces. Concrete, asbestos, plastic and other pipes of suitable diameter are also used. You can drill holes in such pipes yourself, and it is not difficult to stick mesh filters on waterproof silicone.
In accordance with the three-dimensional plan, trenches come off. The central line is being laid, as deep as possible with an optimal slope within 30 ° and a pipe diameter of 100 to 150 mm. Radial and perpendicular bends, with a pipe diameter of 50 - 75 mm or up to an inch and a half, are looped onto the main pipe.
A trench measuring 50x100 cm is pre-filled with a sand-gravel mixture and well rammed. Hexotextile is laid, drainage pipes are laid, the space is covered with crushed stone and covered with hexotextile fabric. The trench is filled with fertile soil.

Combined drainage systems and non-standard methods for draining swamps

The third method - combined is to combine the first two methods of draining swamps. Most often, this method is used in suburban areas.

As a rule, the main central route is made underground - the main drainage pipe is laid, into which excess water flows through the ditches. The technology of installation and laying of the drainage pipe is standard. The supply of sewage ditches is described above in the paragraph on the open method of draining groundwater when the land is swamped.
Heavy and clayey soils often cause a swamp on the site. radical and effective method The solution to this problem is to remove clay soil. In the designated area, the loamy rock is removed to the groundwater horizon. The bottom of the excavated pit is covered with sand and gravel, rammed in order to serve as drainage in the future.
The question of how to fill the swamp on the site depends on what you are going to grow on it. Dense and fatty chernozems can be diluted with peat mixtures or calcium sands. Fruit trees do not grow well on waterlogged soils, so pick up moisture-loving shrubs or gourds.

The original method of eliminating the swamp on the site will be to convert it into artificial pond. It is only required to deepen the territory, strengthen the shores of the artificial lake and ennoble the surrounding area. Moisture-loving weeping willows, fern, shadberry, hawthorn or Amur lilac will look beautiful along the banks. Tables and benches will complement the cozy natural corner. For perfect harmony, you can turn to specialists in landscape design.

Waterlogged lands, swamps and causes of waterlogging

The main tasks of draining swamps, swampy and excessively moistened lands are reduced to the creation optimal conditions for crop growth. Swamps are areas of land that are constantly or periodically in a state of excessive moisture, and within which the thickness of peat reaches 15–20 cm.

Wetlands are subdivided into lowland, upland and transitional bogs.

Lowland swamps are formed in the floodplains of rivers, near lakes. In such swamps, peat has a high ash content (up to 30% of the dry matter mass). After draining the swamps of this type, peatlands become very valuable agricultural land, since they contain up to 3.5% nitrogen, up to 1.7% phosphorus and up to 0.25 potassium.

Raised bogs are common in watershed areas and are fed by atmospheric precipitation and melt water. characteristic vegetation theirs are mosses. Raised bog peat has a low ash content - no more than 3-5% of the mass of dry matter, it is acidic (pH 3.5-5). After drainage and inclusion of raised bogs in agricultural circulation, the application of organic and mineral fertilizers is required.

Marshes of the transitional type occupy an intermediate position between lowland and raised bogs and are formed in areas that are subject to temporary moisture.

The main causes of swamping or excessive moisture of territories are atmospheric precipitation and unregulated surface runoff, which contribute to the accumulation of excess moisture in the territory; surface water coming from watersheds or rivers (during flood); ground water lying close to the surface of the earth. All this, ultimately, creates favorable conditions for the development of swamps or excessively moistened soils, and for the normal development of plants in such areas, drainage measures are required.

If the main cause of waterlogging or excessive soil moisture is surface water, then in this case the tasks of drainage measures are:

1) acceleration and regulation of the flow of these waters with the help of open channels;

2) interception surface runoff and flood water ditches; protection from flood waters is carried out due to the construction of dams.

With excessive moistening of territories due to groundwater, the task of drainage is reduced to:

1) accelerating the outflow of soil and groundwater by lowering groundwater levels with the help of drains;

2) interception of underground flow in elevated areas, flowing "from the side", by trapping ditches or drains.

The designed drainage should provide the required rate of drainage - a decrease in the level of groundwater below the earth's surface by an amount that provides a favorable water-salt regime for the growth of crops throughout the growing season. The rate of drainage depends on the type of crops, climatic conditions and soil structure.

Table 8 shows the average drying rates for some crops under conditions middle lane Russia and Leningrad region.

Table 8

Average rates of drainage of agricultural crops

The drainage network is a complex engineering structures and devices with which the required rate of dehumidification is achieved. It includes:

1. Fencing network - to intercept and divert surface and groundwater entering the drained area from the outside (upland ditches, dams, etc.)

2. Drainage (regulating) network - for collecting and removing excess surface and ground water from the drained area (a number of open ditches and closed drains)

3. Water supply network - for transporting water from the protective and drainage network outside the drained area to water receivers (drainage and main ditches);

4. Water intakes - for receiving water collected by the drainage network (rivers, lakes, ravines).

The drainage network consists of open ditches or closed drains located at a certain distance and depths, which intercept or absorb excess surface or soil-ground water in the drained area. The depth of the elements of the drainage network and the distance between them must be such that, on the one hand, to ensure the rate of drainage, and on the other hand, not to interfere normal operation agricultural machines.

For drainage of agricultural areas, open or closed horizontal drainage is usually involved.

6.2.2 Dehumidification by open channels

Open drainage or drainage by open channels is the simplest and cheapest way to drain swampy and excessively wet areas. Depending on the purpose, these channels are drainage (serve to lower the groundwater level) and collecting (to accelerate surface runoff).

The location of drainage canals in the drained area depends on the soil, topographic conditions, and the planned use of the drained lands (gardens, orchards, arable land, etc.).

Drainage channels are usually cut under acute angle to the horizontal of the terrain, and in the case of soil feeding of swamps - at an acute or right angle to the direction of the ground flow. The depth of shallow open ditches (as well as the distance between ditches) is determined by the required drainage rates for certain crops. The depth of ditches in drained meadows and pastures is 0.8–1.0 m, in fields - 1.0–1.2 m, in orchards - 1.2 m. in table 9.

In Russia, there is a lot of experience in draining floodplain swamps and wetlands also by single channels, traversed to a great depth (more than 1.5–2.0 m). Such a ditch ensures the distribution of the drainage action away from it by 500-2000 m and allows you to drain the area of the territory without additional involvement of a small systematic network.

In addition to permanent open ditches, temporary ditches or furrows are also involved in the drainage of excessively moistened areas. They are traversed by special ditchers across the slope with a slope of about 0.001 and are periodically liquidated (buried) - for the period of planting or harvesting.

The disadvantages of open drainage are that they interfere with the normal operation of agricultural machines, occupy useful agricultural areas, and quickly go out of order - as a result of their clogging, silting, overgrowing, etc.

Waterlogged soil on the site is always a problem. Unpleasant fumes, hordes of mosquitoes in summer, wetting of garden plants poison the life of lovers of country rest. The swamp needs to dry up. How can I do that?

First of all, you should understand the causes of stagnant water in the soil. Depending on this, develop a strategy to combat this unpleasant phenomenon.

Causes of waterlogging of the soil

It is not so easy for a specialist to figure out what caused the swamp to form. It is useful to inspect neighboring lands, to get acquainted with the surroundings. Here are 2 main reasons for excess soil moisture:

The site is located in a lowland near a natural reservoir, groundwater comes very close to the surface;
The natural flow of water after rains is disturbed.

The first reason is less likely to be true - people usually do not take building plots in a swamp. Problems with insufficient water drainage are much more common. The root of the problem could be:

the site has natural source, feeding the swamp, requiring clearing and drainage of water;
your garden plot located below the neighboring ones, all the water after the rain flows down to you;
features of the structure of the layers and relief: a thick layer of clay is located close to the surface, which does not allow rainwater to be absorbed;

How to get rid of the swamp?

The first piece of advice you'll get is to fill the swamp with sand or soil. This is the easiest, cheapest and most wrong way. This method does not bring positive results, sooner or later the swamp returns to its mind. It is an unusually stable ecological system.

It is impossible to displace water by filling. It also won't work to pull it out. There is only one way to completely drain the swamp - to let the water leave this area. To do this, make drainage, through which water will flow. It’s good if she has somewhere to go, but it happens that the site is lower than the neighboring ones or there are obstacles in the way of the running water (building, road). In this case, it is useful to choose a compromise option.

Here are a few good ideas allowing to "dry" the marshy soil. Often these decisions are always the wisest.

Make a pond

Growing up, trees absorb and evaporate everything more water, acting like a constantly running pump. If the soil on the site is heavy, clayey, then the roots of trees, penetrating it in different directions, gradually change its structure.

If the site is large enough, then planting such natural dehumidifiers along its perimeter will be effective, and the efficiency will increase every year.

Make a catchment well and drainage

If the site is small and there is no place for a pond, then you can make a water intake well. It is a construction of concrete rings or a plastic container (this option is simpler and more practical). It is protected from clogging and silting with sprinkling and geotextiles. Drainage pipes are brought to the well to collect water from the site.

The water that is collected there can be used for irrigation during dry times or pumped out and discharged through pipes into a natural reservoir.

The water well is considered the best option for the area under which lies a layer of clay, and the layer fertile soil small on top of it. Rainwater in such a place does not go deep, so in spring and during the rains there is a swamp, in summer heat the soil dries up. Mosquitoes, silt, the smell of rotting mud - these are the delights of such a site. Growing anything is hard. What does not dry out in the spring will dry up in the summer, but there is no benefit.

You can build a drainage system, including a water intake well and grooves for collecting water, and you can do it yourself. The cost of such a structure is small, and the benefits can be invaluable.

In the event that these measures do not help get rid of the swamp, then only a specialist can help solve the problem. A full-fledged drainage system with all the work is not cheap, but only this way will get rid of the waterlogging of the soil.