For example, some cyanobacteria have structures called heterocysts that provide a low-oxygen ... nitrogen cycle. In agricultural systems, fertilizers are used extensively to increase plant ...

Save guides, add subjects and pick up where you left off with your BBC account. A farmer sprays nitrate fertiliser on his land around a lake. Can you put these steps in order to describe how the ...

For example, some cyanobacteria have structures called heterocysts that provide a low-oxygen ... nitrogen cycle. In agricultural systems, fertilizers are used extensively to increase plant ...