一个主要的问题是，退化的土壤变得密实，造成吸水量减少，从而导致水从地表流失并将表土带走。

One major problem is that degraded soils become compacted and so absorb less water, which then tends to run off the surface, taking topsoil with it.

youdao

在许多国家里，生产性表土的流失已导致日益严重的粮食短缺。

In many countries the loss of productive topsoil has contributed to growing food deficits.

youdao

严重的水土流失不但可以导致生态环境恶化，而且对地表土层的破坏，会使土地的生产能力下降，影响农业生产。

The water and soil loss not only bring on entironment worsement, but also reduced the capacity of ground yield by destroy surface layer of soil.

youdao