In the lawn, when the water does not filter properly into the soil, harmful water accumulations can be created that ruin the lawn and the plants present. In this case it is necessary to carry out some rehabilitation works, the so-called “hydraulic adjustments”.
In some cases, the lawn soil may be too rich in water or it may not eliminate the water within a reasonable time and therefore always remain wet. In these cases it is essential to intervene to avoid compromising the regular growth of plants, especially when the problem concerns the turf, which is particularly sensitive to the negative effects of water stagnation: fungal rot, poor vegetative vigor, formation of moss.
In soils, stagnation can be superficial, due to the fact that the intensity of rainfall exceeds the speed of infiltration of water into the soil, or underground, caused by high groundwater, therefore more persistent and more serious than the former.
The agronomic works and works necessary to ensure the management of water in the soil are defined as “hydraulic land arrangements”. Let’s see how to deal with the problem, with the laying of an underground drainage, or with the construction of a network of underground porous pipes, called drains.
In a soil, the deep flow of water can be too slow, or even prevented, basically for two reasons, sometimes associated:
- poor soil permeability, a situation that occurs frequently in clayey and loamy soils, naturally poorly draining;
- difficulty in draining towards the deeper layers of the soil due to natural obstacles: in this case the water regularly infiltrates the first 50-100 cm of soil, but then, encountering layers of rock or very hardened and compact subsoil, it no longer percolates, stagnating above the physical barrier encountered.
Before proceeding to the solution, you need to understand what your case is.
The excess of water in the soil determines harmful effects, which are often made even more serious by other concomitant factors such as the cold climate, the continuous passage of the means of work that compact the soil even more or the cultivation of plants in need of a limited quantity of water.
The most serious problems concern parasitic damage to the roots: the accumulation of water in the thickness of the soil that can be used by the plants, determines the favorable conditions for the development of many harmful fungi that quickly attack the roots, causing them to rot.
Other problems are due to the limited recirculation of air in the soil and consequent root asphyxia, the reduced absorption of nutrients and the limited root development both in depth and in extension.
How to Solve it
To dispose of the excess water present in the soil, you can proceed in a different way. Some agronomic interventions are simple and easily adopted even in the home, others are more complex.
The most practical, extremely effective, in many cases decisive, is the laying of an underground drainage, which involves excavations to create a network of drains, porous underground pipes that collect percolation or groundwater and convey it to a point collection. It is not a very simple technique and can only be implemented by those with the equipment and good dexterity.
Or it is necessary to resort to a professional maintenance of the green.
How to proceed
- Initially you need to evaluate the state of your lawn: level of humidity and size of the space on which to intervene.
- Then we proceed to trace the pipes on the ground: the laying lines of the drains must be parallel, at least 1-2 meters away from each other.
- Then the final connection point is established, in a naturally lower area.
- If the ground is completely flat, the slope of the excavation must also be studied to create a lower connection point.
Where to place the pipes
It is a rather variable figure: from 40-50 cm up to 120-140 cm depending on the type of soil and the crop concerned. Indicative values of the depth at which to place the drains are:
- Grassy carpets: from 40 to 60 cm
- Home gardens and open field horticulture: from 40 to 100 cm
- Fruit trees, ornamental plant nurseries: from 80 to 120 cm
Drains laid too superficially can be moved or damaged during the working of the soil (plowing, digging, hoeing), those placed too deep can become ineffective for collecting water.
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