Drainage of grassy sports grounds with a net of drains and collectors turned out, in many cases unsatisfactory. This is due to soil subsidence and a decrease in soil porosity due to various factors. These phenomena cause the reduction of non-capillary voids, the soil is completely saturated with water. Prior to the occurrence of subsidence, the non-capillary spaces did not hold water and there was air movement through them. Filling all spaces with water prevents air from reaching the roots. In confined spaces, transformed into capillaries as a result of subsidence, the water remains for quite a long time even after the free water level drops significantly, therefore, plant roots may be deprived of oxygen for extended periods. Long-term excessive moistening of the lawn soil deteriorates the living conditions of the lawn plants, and at the same time may make it difficult to use. Such lawns can be slippery and are very easily damaged mechanically, especially if they cover football fields. For the reasons discussed above, the lawns of sports fields must be equipped with very efficient and fast-acting drainage systems.
A way to protect the pitch against excess water and lack of air in the soil: 1 - filters ø 50 the 75 mm surrounded by sand, 2 - fine sorted gravel layer ∅ 10- 20 mm, 3 - a layer of sorted fine gravel ∅ 2 – 5 mm, 4- earth (60% sand and 40% garden land with peat), 5 - turf.
A very good way to drain lawns in sports grounds is shown in the picture. This method differs from the top drainage network in that, that under the entire surface of the lawn at a depth below 15 cm is a layer of aggregate without capillaries. Thanks to the arrangement of this layer, excess water is easily drained. The spaces of this layer” they are always free and there is air in them, the main mass of the roots is kept at 12 -15 centimeter layer of soil, but in the event of long-term drought, the roots that grow below may take up water from the substrate. The described method of drainage is very good for use on heavy soils, clayey.