崩岗植物治理技术及效果

<正> 一、快速生物治理崩岗技术问题的提出 崩岗是花岗岩山丘水土流失发展到最严重阶段的产物。它是由沟蚀、重力侵蚀作用下,由崩壁(崩塌造成的峭壁)、堆积坡(在崩壁下部由崩块和泥砂堆积而成)和崩口(崩岗径流出口)组成的地貌形态。峭壁一般坡度在70度左右,堆积坡也多在45度左右。崩岗地表由松散的风化物组成,坡度大,易于受径流的冲刷、搬运,源源不断的下泻物,危害山下良田,淤塞河道。 对于崩岗治理,过去曾进行过生物治理、工程治理,也采取过“上拦、下堵、中间削”等治理方法,但都未能奏效。原因在于,生物治理,种植难度大,新种植物经常被冲被埋,难以成活;工程治理中的拦沙坝需要不断加固加高,投资大,效益小,等等。使治理进度受到影响。为此,我们根据多年实践经验,提出了以植物的生长速度战胜流失速度的治理设想,并设置了快速形成植被覆盖的治理技术试验研究课题。

Technique and Effect of Controlling Soil Loss by Vegetation in Benggang Area

Benggang is a kind of erosive geomorphic form in granite gullied-hilly area in South China , which causes serious soil loss and brings about extreme harm to local produc tion and is difficult to be controlled. According to many years of conservation practice, experiment of controlling techniques by rapidly forming vegetative cover was made in Benggang area of Meixian County, Guangdong Province. This experiment took the way of combining engineering measure with vegetative measure, adopting different criteria of general layout of plants on basis of topography and, strengthenning the tending and management for vegetation. The vegetative cover reached more than 90% in the same year when the plant was laid out, and the surface runoff and sediment was reduced 29.3%and 99.1%respectively. The condition of soil fertility and soil moisture was improved obviously. The success of this experiment had provided technical experience for control of soil loss in the Benggang area.