随著施氮量增加,追施氮肥的利用率明显下降.用英语怎么说？

随著施氮量增加,追施氮肥的利用率明显下降.

The nitrogen utilization efficiency were downtrend with the amount of topdressing increased.

the

art. 指已提到的人（物），指说话人与听者已知的人（物），用于独一无二的事物前，与形容词最高级和序数词连用；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

nitrogen

n. [化]氮，氮气；

例句
The faeces contain nitrogen and it is that which fertilises the desert soil.
粪便含氮，而正是氮可以肥化荒芜的土地。

utilization

n. 利用，使用，效用；

例句
Introduces the concepts of available anergy and reduced exergy by analysing the energy utilization process.
通过对其能量利用过程的分析,引入可用和折合的概念.

efficiency

n. 效率，效能，实力，能力，[物]性能，功效；

例句
There are many ways to increase agricultural efficiency in the poorer areas of the world.
有很多方法能够提高世界贫困地区的农业效率。

were

be的过去时复数和第二人称单数形式，有时代替 was,用于条件从句、动词 wish 之后等；

例句
Shops, houses, and vehicles were set ablaze.
店铺、房子和车辆全都陷于火海。

downtrend

n. 下降趋势；

例句
The nitrogen utilization efficiency were downtrend with the amount of topdressing increased.
随著施氮量增加,追施氮肥的利用率明显下降.

with

prep. 和，跟，随着，关于，和…一致；

例句
A waiter entered with a tray...
侍者端着托盘进来了。

amount

n. 量，数量，总额，本利之和，全部效果，全部含义；vi. （在意义、价值、效果、程度等方面）等于，等同，接近，合计，总共，发展成为；

例句
This may provide a quick and accurate way of monitoring the amount of carbon dioxide in the air...
这也许能提供一个监测空气中二氧化碳含量的既快又准的方法。

of

prep. 关于，属于…的，由…制成；aux. 助动词 [非标准用语、方言] =have [主用于虚拟语气]；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

increased

adj. 增加的，增强的；v. 增加，增大，增多( increase的过去式和过去分词 )，增强，增进，[缝纫]放（针），增强；

例句
Warren also allows that capitalist development may, in its early stages, result in increased social inequality.
沃伦也承认资本主义发展初级阶段可能会导致社会不平等现象加剧。