Choose a fertilizer that contains nitrogen, phosphorus, and potassium.
选择含有氮，磷和钾的肥料。
2
Ammonium sulfate is also used as a fertilizer (although in much higher concentrations), but it only contains nitrogen but neither phosphorus nor potassium.
作为肥料应用的硫酸铵浓度会更高，但其中只有氮的成分，没有磷或钾。
3
The effect of potassium increased with increasing yield and nitrogenfertilizer.