Airing coring and sandblasting
The aeration is a practice that has the purpose of creating better conditions for an exchange of air and water in the soil, improving water penetration and fertilizers, thanks to the less compaction of the soil. In fact, if the lawn is used and trampled for a long time, it has a compact surface that leads to the degradation of the grassy turf. In addition, a layer of felt can be formed on top of it, that is to say of indecomposed plant tissues which give rise to a semi-permanent crust within which molds and diseases can develop. To overcome these two problems, machines that act on the ground and on the turf are usually used: the verticut, for example, removes the felt thanks to the rotating knives mounted on a horizontal cylinder, and brings it to the surface where it can be easily collected. Scarifiers or scarifiers, on the other hand, act on the ground at a superficial level, making incisions at depths of between 2 and 5 cm. For a more incisive intervention, on the other hand, other equipment is used, which is called core drills or punching machines, which cause a very thick hole in the grass even at a depth of 30 cm. Usually two types of core drills are used: the stellar type has a series of dies mounted on a horizontal cylinder, while in the vertical the same punches puncture the ground perpendicularly by extracting the earth cylinders. In some cases it is also possible to use soil-decompacting machines that work either with vibrating blades or with high-pressure water jets directly into the ground. Subsequently the decompacted and perforated soil can be recharged with other materials, in particular with sand, which protects the grass collar improving the resistance to trampling. It is advisable to use silica and non-calcareous sand because the latter would modify the soil pH. As for the quantities, they vary depending on the function of the lawn: after a coring operation on a football field, about 3-4 l / sq.m must be made, while on a maid field at most 1l. Avoid these processes at times when the plant could suffer cutting stress, in full summer or winter, or how much weed could favor the germination of the pests. In general, the most suitable period is the beginning of summer.