Natural soil fertility is dropping in many areas because of continuous industrial fertiliser and pesticide use, while the growth of algae is increasing in lakes because of the fertiliser run-off.

在很多地区，由于工业化肥和农药的持续使用，导致自然土壤的肥力正在下降，然而化肥的流入却导致湖泊中藻类生长得越来越快。