When the soil underh your lawn bees pacted, it reduces root growth as well as the grass’ recuperative ability, thus increasing a lawn’s relative susceptibility to dias.
Aeration improves shoot and root growth and recuperative ability, and decrea the likelihood of dia and inct damage.
Thatch is a partially depod layer prid of roots, stems, rhizomes, s, and stolons situated above the soil surface. Up to a 1-1br2 “layer of thatch is beneficial and provides insulation to roots, reduces soil water evaporation, cushions playing surfaces, and may prevent soil pa. However, thatch layers greater than 1br2” should be removed to avoid restricted water entry into the root zone, resulting in drought stress.
Several turf grass pathogens survive ihatch layer, including tho that cau summer patch, leaf spot, aing-out dias. Bermudagrass, Kentucky bluegrass,and kikuyugrass produce more thatch than most other turf grass and require regular dethatg. Equipmeal business often carry dethatg (verticutting) maes that are specifically desigo remove thatch from home lawns.
土地荒漠化（laification）是由於氣候變化（climate ge）和人類不合理的經濟活動(eic activity)等因素使幹旱(arid)、半幹旱(miarid)和具有幹旱災害的半濕潤地區的土地發生退化(degradation)。土地荒漠化是全球性的環境災害，它已影響到世界六大洲的100多個國家和地區，全球約有1br6的人口生活在這些地區。
導致荒漠化的人為活動主要有四方麵：
(1) 不合理耕種或過度耕種(over cultivation)。土地中的養分(nutrient)和水分被農作物大量吸收，而土地卻得不到足夠的有機質(anic matter)和水分的補充；
(2) 不合理放牧或過度放牧(razing)。牧場上牛羊吃草的量超過了土地能生長的草量，使土地裸露，水分蒸發，有機質喪失；
(3) 在降雨(precipitation)不足以供應農作物需求的地方把牧區(pasturing area)改為耕地；
(4) 在樹木生長不易的地區砍光所有樹木。