Why dose a whole field with chemicals if you can spray only where they are needed?

如果你可以只在需要的地方喷洒化学药品，为什么要在整个田地里喷洒呢？

youdao

The fruit is injected with chemicals to reduce decay.

水果注入了化学药品以防腐坏。

《牛津词典》

He explained our basic task, the tractor fired up and we were off, riding down the field looking for weeds to spray with chemicals.

他向我们解释了我们的主要工作：拖拉机发动起来，我们就出发，沿着田野寻找可以喷洒化学药剂的杂草。

youdao

They allege that the company's drilling polluted their water with chemicals,metals and methane, the main constituent of natural gas, causing explosions as well as gastrointestinal and neurological illness.

VOA: standard.2010.01.02

Sylvie asked. "No." he answered slowly, "I shoot them and stuff them with special chemicals to preserve them.

VOA: special.2010.04.03

Mister Venter says his team made each watermark sequence with the contents of four different bottles of chemicals.

VOA: special.2010.07.20

And he says the U.S. is replacing known chemicals with chemicals about which little is known.

NPR: New Safety Law Doesn't Mean All's Well In Toyland

Cytokines like interleukin-1 are not always harmful, but they can interact with chemicals in the brain.

BBC: Cot death remains a mystery

The water system will continue to be flushed with chemicals until clear results are returned from the lab.

BBC: Lincolnshire