Introduction to Green Conservation Practice-Trace and Frequent Sanding
The lawn is a living biological system, constantly growing and dying, coupled with the cuttings of the grass, making a large amount of organic matter continuously accumulate in the roots of the grass. These accumulated organic matter will eventually become the withered grass layer. The withered grass layer is a layer of material composed of plant remains and soil between the bottom of the grass canopy and the top of the lawn soil. The withered grass layer will not only hinder the exchange of soil moisture and air, affect the health of the lawn, and form dry patches, but also cause various cutting effects. Part of the withered grass layer (organic matter) is degraded by microorganisms and turned into minerals that are re-absorbed and utilized by plants. However, this degradation process is different due to differences in microbial activity, air permeability and total organic matter. The air permeability of the grass canopy directly affects the activity of microorganisms. The continuous accumulation of organic matter will reduce the air permeability of the grass canopy and roots, reduce the degradation rate of organic matter, and accelerate the formation of the withered grass layer.
For sandy greens, if the organic matter content (weight) in the roots exceeds 3-4%, many secondary problems will occur, such as lawn diseases, dry patches, soft lawn surfaces, poor root growth, Black soil layer, and more often high temperature damage. Therefore, the normal lawn maintenance practice every year requires drilling, cutting roots, and conventional sanding to remove organic matter and the dead grass layer, creating ventilation channels to accelerate the degradation of the remaining dead grass layer and ensure the health of the lawn.
The traditional sand paving after punching, generally use a roller brush sander to pave a large amount of sand back to the lawn to fill in the holes just punched out. These loose new sand can retain the permeable and air-permeable passages of the lawn for a long time, so that fresh oxygen can enter the root system and the withered grass layer area under the grass canopy, promote the strong growth of the root system, and more importantly, accelerate the degradation of the remaining withered grass layer, thereby Substantially remove the withered grass layer. However, this heavy-duty sand paving will eventually cause the root soil to form a layering phenomenon, resulting in a decrease in water permeability and air permeability.
If a thin layer of sand is spread on the lawn while the lawn is growing, this layer of sand can mix with the newly generated organic matter (dead grass stems, grass blades and grass clippings) to ensure air circulation and The activity of microorganisms can quickly degrade organic matter, slow down the formation of the withered grass layer, improve the health of the lawn and increase the ball speed. This is the main purpose of micro-sanding. Micro-sanding refers to spreading sand at 0.06-0.1m3/100m2 every 10-14 days (sometimes up to three weeks apart) throughout the growing season of the lawn. Generally speaking, the maximum amount of sand for creeping bentgrass is 0.2m3/100m2. Micro-sanding needs to be carried out frequently to match the growth rate of the lawn, so it is often called micro-sanding (dusting and frequent topdressing). Frequent micro-sanding can make the sand evenly mix with organic matter and degrade it. Eventually, the sand will evenly become root sand, improve the overall humidity of the root soil, and have more consistent water seepage and drainage capabilities, and help Form a compact and even putter surface.
Although the traditional methods of controlling the withered grass layer (such as drilling, cutting roots, and traditional sanding) can effectively control the withered grass layer to a certain extent, it will inevitably produce delamination and will damage the lawn to a large extent. Need a lot of manpower and close the stadium. A small amount of sanding can alleviate the formation of a layer of dead grass and help to form a uniform and firm green surface, thereby reducing the use of traditional methods.
In addition, some studies have shown that greens with a small amount and frequent sanding during the growing season will have a faster ball speed than greens with heavy sand in spring and autumn. For example, the University of Nebraska in Bent Experiments were conducted on grass greens and found that the greens with 0.08m3/100m2 micro-sanding, and the greens with 0.33m3/100m2 sanding each in spring and autumn, the ball speeds were 8.1 and 6.9[2 ].