Simulated composting was carried out to study the changes of biochemistry and chemical characteristics of the organic manure compost using labelled organic material and inorganic nitrogen fertilizer.

通过室内模拟堆制和同位素交叉标记，研究了以稻草和禽畜粪为主体材料的堆肥制作过程中的生物化学变化特征。

youdao

In cases where sewage sludge is used, expensive chemical fertilizer use can be avoided, he said. The sludge contains the same critical nutrients-nitrogen, phosphorous, and potassium.

有时候，人们用下水道污泥来代替昂贵的化学肥料，其中一样含有重要的营养成分——氮，磷和钾。

youdao

Nitrogen phosphorus chemical fertilizer combined organic improve yield, more ideal way of fertilizing. But should pay attention to the plain supplement of potassium at the same time.

氮磷化肥配施有机肥具有持续提高产量、培肥土壤的双重效果，是砂姜黑土培肥改良较理想的施肥方式，但同时要注意钾素的补充。

youdao

But improved farming methods later increased their yields and, at the same time, made better use of chemical nitrogen fertilizer.

VOA: special.2009.07.28

Scientists at the agroforestry center say the use of fertilizer trees can reduce the need for chemical nitrogen by up to three-fourths.

VOA: special.2009.09.01