我们需要降低水中的硝酸盐含量。

We need to cut nitrate levels in water.

《牛津词典》

因为大量使用化肥，中西部地区的硝酸盐含量很高。

High levels of nitrate occur in the Midwest because of the heavy use of fertilizers.

《柯林斯英汉双解大词典》

一些浮游植物可以通过固氮在硝酸盐含量较低的地区生长。

Some phytoplankton can fix nitrogen and can grow in areas where nitrate concentrations are low.

youdao