Its a popular problem that the lawns built with greensward rolls are short-lived, although they can form lawns rapidly. Some need to be replaced within one or two years. The greensward roll normally lasts for more than 5 years. Why are these kind of things happening?
The quality of the greensward roll is low. The quality of the greensward roll directly affects the service life of the lawn. Wang Deqing, a manager of Green Capital lawn production basis explains that, in order to shorten the production cycle, some producers increase the planting density. The greensward rolls produced this way are easy to get diseases after being spread. Su Ailian, a grower in Beijing Clover technology developing center of grass said that, some producers sell the greensward rolls when the density of grass roots is low for the sake of economic benefit. These lawns can only be renewed by fine cultivation and conserving. Otherwise the lawn will not last long.
The soil melioration is not properly carried out. This is an important factor to the lifespan of the grasses. The grassland soil is the basis of the grass growing. Su Ailian thought that the soil should be air and water permeable, and have the capacity of retaining fertilizer and moisture, so that the grass growth will not be affected later. If the soil is not standard, it must be meliorated. Han Liebao, president of Beijing Forestry University graduate school of lawn, said, I am personally oppose the way of constructing lawn by spreading greensward rolls, because there may be great difference between the soil of the greensward rolls and the soil of the grassland. For example, the soil of the grassland is infertile and hard, while the ground substance of the greensward soil is loose. The two layers of soil cant integrate, and the grass can hardly take root. This directly affects the service life of the lawn. Hou Xiangdong, the engineering department manager of Beijing Lanyuan Greening Engineering Co. Ltd said that, some constructing units dont meliorate the soil to save efforts; the soil is lack of organic matters and not loose; and the soil is further hardened by being watered and tramped; thus the grasses dont grow well and last long.
The lawns are not taken good care of. The service life of lawns differs much for being differently taken care of. Wang Deqing introduced that, there is a patch of lawn on the crossing of Ganluyuan. The lawn is constructed with greensward rolls in 1998 and taken care of by Chaoyang afforesting team I. Its still in good condition to this day. Some of his clients are owners of top-grade villas. The lawns of these villas need to be replaced almost every year. The difference is mainly caused by the level of maintaining and preserving. Li Dong, general manager assistant of Beijing greening and gardening bureau lawn base said that, for the construction of lawn, maintaining should be paid more attention rather than planting. But in many places, the situation is reversed. The lawns that are not carefully maintained tend to get plant disease and insect pests in summer, and get drought in winter, especially the cold season lawns. Therefore the service life of lawns is shortened.
Over-drought, over-humidity, plant disease and insect pests, and salt damage will all affect the service life of lawns. Li Wenge, deputy captain of capital airdrome afforesting team said that, the normal service life of lawns in Beijing should be 5-7 years. The grass is easy to die due to lack of water. Therefore, irrigation must be carried out in time in dry season, and there must be enough water for the grass to endure cold weather and shoot up.
Yuan Xiaohuan of Beijing research and development center of grass industry and environment said that, there are many mistake ideas in the management of lawns. Some think the cold season lawns are water-consuming and irrigate the lawns frequently. As a result, some lawns are over-irrigated. This is a kind of waste of water. And the lawns are easy to get plant disease and insect pests. Plant disease and insect pests is an important factor that affects the quality and service life of lawn. Liu Kui, head engineer of Jiangsu landscape and garden construction co. ltd said.
Besides, Yuan Xuewen from the Beijing greening and gardening bureau think that the salt damage caused by snow thawer also causes the lawn to die.