> Cool. And which of those can I generate using excess electrical energy from my solar panels?
Perhaps use the excess energy to power an electric wood chipper to process your garden's waste? Wood chips made from small branches are quite rich in nitrogen.
> Over the last 3 years I've imported almost 5000kg of animal manures into my gardens.
What size garden do you have? The recommended dosage of manure is 30-50T per hectare, so 3-5T per 1000m2, but this is for the most exigent vegetables.
> Its more important for me to have the independence and control over my food-supply than it is to hold to a particular relgiosity around where my N comes from.
When you use a chemical fertilizer you depend on the manufacturer and distributor. How can this be called independence?
There are important differences at the soil biology level between the N coming from a chemical fertiliser or assimilated by soil bacteria. The former induces plants to use more water, necessitating more frequent watering. It also infiltrates ground water and pollutes aquifers. Another externality is greenhouse gas emissions in the process of manufacturing it.
> When that fails, I'll use a pesticide.
I'm not passing judgement but I think it's important to understand the consequences of our choices. At this point it is common knowledge that chemical fertilizers and pesticides are harmful to the environment and to people's health. I think it's important to be aware of the externalities implicated in all those choices. They might be easier, faster, cheaper in the short term, but in the long term they may prove to be introducing problems that are much harder, slower, much more expensive to solve in the long term.