Topsoiling is the application of a thin layer of soil to an established or growing lawn. On established lawns, turf cover can serve a variety of purposes, including controlling the hay layer, leveling the surface of sports turf, promoting the recovery of injured or diseased turf, protecting putting greens in winter, changing the properties of the turf growing medium, etc. The genetic characteristics of the lawn, natural environmental conditions, cultivation and management methods and the purpose of lawn establishment determine the need for surface covering soil. Golf greens, bowling greens and other sports venues require lawns that are very uniform to facilitate labor. Small to medium-sized irregular surfaces are caused by trampling, weather conditions, turf growth and other factors. Such small and medium-sized undulations can be adjusted by covering the surface with soil. Fruit collars covered with surface soil are less prone to hay accumulation or other related problems. Fruit collars built on unsuitable soil can eventually form a good lawn with improved drainage, good ventilation and strong resilience after being repeatedly covered with suitable soil for many years. Therefore, this measure has become an important means in sports field lawn management.
一、Layering A common problem related to surface covering soil is the layering effect caused by the long-term application of soil that is different from the lawn soil medium as covering soil. When there is sand or other coarse materials in the soil profile, the upper soil is often in a moist state and root growth is hindered. Small differences in soil types in the soil layer, such as the lawn root layer, will also cause great adverse effects on the lawn root distribution. Furthermore, the amount or frequency of covering the surface layer with soil is not sufficient to ensure that the soil layer is fully mixed, and over time the soil and organic residues will separate. In some cases, vertical pruning is sometimes necessary before the top layer of soil is applied to open up the grass layer to prevent layering. Crushing the perforated soil strips after drilling can produce the same effect as surface covering soil. As long as the soil beneath the lawn is suitable, this breaking-up process is the same as or better than top-dressing with foreign soil.However, the amount of soil broken up is determined by the intensity of the drilling (size and number of holes) and the amount of drilling that the lawn can tolerate. Top soil cover, on the other hand, is not affected by these factors and can be carried out without any other tillage measures. When drilling and covering soil at the same time, care needs to be taken to prevent layer formation. For example, when covering the fruit collar with sand, holes are often drilled first to ensure that the sand enters the holes. The soil strips brought out of the hole should be removed. The soil strips cannot be broken in situ until the thickness of the sand exceeds the maximum penetration depth of the drilling machine. Otherwise, discontinuities between sand and soil will occur, causing adverse effects.
二、Selection of surface covering soil Selection of soil used as surface covering soil is one of the most important aspects in lawn management. Therefore, when building a new fruit collar, some soil should be set aside in advance for later use. The soil required for flat soil and top cover soil only differs in soil organic matter content. Top cover soil does not need organic matter because the lawn growth will produce enough organic residues for future needs. In fact, one purpose of top soil mulching is to promote the decomposition of these organic matter to prevent the accumulation of excessive hay layer. If the local soil is unsuitable, the collar must be rebuilt or a suitable topsoil selected, depending on the severity of the collar profile problem and the level of collar quality expected to be achieved through topsoiling, management or other measures. Choosing off-site soil is more difficult because it is difficult to achieve the same composition. It is generally considered to use sandy soil. Recently, people tend to use sand entirely, and the results show good results. However, if sand is used endlessly for a long time, a sand layer will appear, resulting in a hard surface, which requires more water and fertilizers in daily management. If the sand becomes water repellent, the likelihood of local dryness increases.
三、Amount of covering soil The amount of surface covering soil required for each application or throughout the growing season depends on the purpose of covering the soil. If it is to transform a large area of unevenness and make the lawn surface smooth, a large amount of soil will be needed; similarly, if you want to change the soil composition of the lawn root layer, a large amount of soil covering will be required. The amount or frequency of applications is primarily governed by the lawn’s ability to absorb these soils. Too much soil will prevent the leaves from receiving light and affect the growth of the lawn. The putting standard of the golf course also affects the strength of the surface covering soil. The golf course that is not used temporarily needs more surface covering soil, and the golf course that continues to play will use less surface covering soil. When controlling thatch layer, the rate at which thatch layer accumulates determines the frequency and amount of surface covering. Some fruit lawns do not need top soil when they do not grow vigorously or when the conditions are suitable for rapid decomposition of organic residues. For fruit collars where the wither layer continues to develop, it is best to cover the fruit with surface soil. In this case, the amount of surface soil required should be about 15m3/hm2 and about 1.5mm thick covering soil. The top layer of soil and hay mixed together form a useful medium layer in the trampled lawn.Depending on its decomposition, the top layer of soil can change the compactness, change the moisture and nutrient status, and also provide nutrients; the wither layer provides resilience and aeration. Therefore, surface covering soil improves the grass layer in the short term. Over time, due to the surface covering of soil, the dry grass layer accelerates decomposition and the soil organic matter content increases. When applying a large amount of pure sand to the surface covering soil, the application rate can be as low as 7.5m2/hm2, and it can be applied once every two weeks during the growth period. Some people also recommend the application of medium fine sand (0.25-1.0mm). One of the problems with using sand as top soil cover is that dust and other particulate matter enter the sand through atmospheric deposition and irrigation, and large amounts can reduce aeration. For this reason, it is recommended to use periodic drilling and fill the holes with “clean sand” to communicate with the layers closed by particles and ensure good drainage. Frequent surface covering can also be used to dilute these particles and avoid the formation of a sealing layer. Punch holes are necessary to maintain the proper depth of medium in the fruit collar. After a few years, with a considerable amount of surface covering, the height of the fruit collar can increase significantly. The increase in thickness can cause surface drought. Therefore, the amount of surface covering material added should be roughly equal to the amount of soil strips removed after drilling and drilling.
Post time: Jul-18-2024