When you apply nitrogen fertilizers, it is mostly in ammonium form.

我们所施的氮肥，大部分是铵态氮肥。

This information reduces unnecessary water use and tells farmers where they should apply more and less fertilizer instead of causing pollution by showering it across the whole farm.

这一信息有助于减少不必要的用水，并告诉农民他们应该在哪些地方多施肥以及少施肥，而不是把化肥洒遍整个农场而造成污染。

The youngest field workers they could recruit were over 50 years old, and the cost of hiring laborers to apply fertilizers, herbicides, and pesticides was rising year after year.

他们能招到的最年轻的田间工人都超过 50 岁了，雇佣工人施肥、除草和喷洒农药的成本年年攀升。