6. The professor explains how what benefits the weeds offer can be beneficial to the soil by giving two examples. (Wrong grammar structure)
First, he describes that weeds can prevent soil loss caused by soil erosion. To be specific, in traditional agricultural practice, some parts of soil are kept bare. (What does it mean?) So when it rains, lots of topsoil were washed out are lost. But when the weeds covers the bare ground, the soil erosion does not occur because the weed's root hold the soil together.
Second, he describes that weeds enrich and fertilize the soil. Most weeds have a deep taproot that plays a role in bringing up nutrients to the surface. Moreover, when people plant the weeds into the soil, they break down into compost which provides lots of nitrogen to plants. (So that? Need conclusion)
These two examples illustrate how weeds can help the soil to be in better condition.
* How로 가시려면, how beneficial 로 형용사 함께 부쳐주셔야 합니다.
그러나 전체적인 문장구조로 보았을 때 how구조는 어울리지 않으므로 수정하였습니다.
참고하시기 바랍니다.
또한 틀린 단어와, 단수 및 복수 어법에 유의해주시기 바랍니다.