What grows a good crop?

A couple of observations from this years crops confirm our theories about what grows a good crop. The key is plenty of nitrogen, but this can come from release of nitrogen from soil organic matter - not necessarily from nitrogen bought from the fertiliser company.
Firstly, the harvest rain last year provided warm, moist conditions for extra release of nitrogen. This showed up in soil tests. However the differences evident in crop growth are being acheived in various ways. One is from a good history of liming, and another crop I saw seemed to be benefiting from deep cultivation that had incorporated organic matter from the topsoil.

Hopefully, a couple of pics show this story, though there are a lot more examples that support this theory. Just that you don't realise what is going on when you first see it. It only becomes evident when you reflect on what you have seen.