The carbon in manure is converted to biomethane, not the nitrogen and P. The carbon in crops comes from CO2 in the atmosphere. Thus, CO2 from the atmosphere (a major problem) becomes CH4 (energy). The N and P rich “digestate” (i.e., biosolids remaining after digestion) remains a highly valuable fertilizer, now consuming less time and costs (e.g., diesel) to spread. All the best! Here’s a read: http://www.extension.uidaho.edu/publishing/pdf/cis/cis1215.pdf

Everything that goes into the digester comes out in the form of natural soil amendments and fertilizer. Most digester operators either eliminate the purchase of synthetic fertilizer or greatly reduce the amount purchased. Digesters are the central piece in a circular agricultural production system.

You don’t seem to understand the process or purpose of a biodigester very well !
Yes , it, does produce energy ! But, it, also produces an organic fertilizer that can replace oil based fertilizers as well !
I’m thinking that you may have a vested interest in oil based fertilizer !

The feedstock for a digester is basically anything that emits methane – i.e. manure, food waste, etc. The methane is then used to generate electricity or can be turned into LNG. But the feedstock doesn’t go away, it then is digestate organic matter, which is typically applied to fields. It’s not a step backward.

That would be great, Otis! It’s something we’ve already seen with solar energy, for example.