In China, it was used directly for farm fertilizer for thousands of years.

在中国，千百年来它被直接用作农肥的。

youdao

The fertilizer and machinery needed on a modern farm also have a large carbon footprint, as does the network of ships and trucks that brings the food from the farm to your plate.

现代农场所需要的化肥、机械及将食物的从农田运往所需地的船舶和货车都产生巨大的碳量。

youdao

This spring, a federal science advisory report is expected to recommend a national goal of improving the efficiency of farm nitrogen fertilizer use by 25 percent, Herz and Galloway say.

今年春天，一份联邦科学建议报告有可能建议提高氮肥使用率提高25%的国家目标。赫兹和盖洛韦说。

youdao

And since natural gas is a major ingredient in fertilizer, the cost of this essential farm supply could go up,too.

VOA: standard.2009.12.12

But,unlike city sewage, this waste sits in lagoons and is spread untreated on farm fields as fertilizer.

VOA: standard.2010.05.06

Our list includes biofuels companies, commodities and fertilizer concerns, farm equipment makers, and railcar and rail equipment manufacturers.

FORBES: Magazine Article

"It needs oil to make the fertilizer, oil for the farm, oil for the food processing, oil for the packaging and oil to transport it to the shops, " he added.

CNN: Farm in the city could be supermarket of the future