It's great having the time to create great soil. Have you checked Bryant Red Hawk's soil series ?
Do the clovers that you grow actually create these nodules at the roots? Check it out. And you can cut them through with a sharp knife and if the bacteria live in there, it
should be red.
Sand is just added in small quantities, through and through in time. It might just sink in if you throw it on top. Maybe consider making your pathways of sand to see what it does. Pebbles.. Why?? Because sand and pebbles make water drainage. French drains consist of them. Water drainage makes the rain pushes through the soil in screen like qualities pushing air bubbles around. In my mind's eye i see it.
I use sand in my plant start seed mixes. It makes the water run down, so the plants have to root down well. I need those roots down, but you might not.
But don't take my word for it, just read up and experiment, that's the only way forward, because i can talk all i want, i have no experience with peat.
Speak to elderly gardeners too, at the allotment. They might have some great tips to improve soil, about what plants work and which ones don't.
And yes, yes to drainage into the ditch. But again talk to the people with hands on experience there. In summer you might want to block the drainage, drought is becoming a problem everywhere with climate chaos.
The elder folk will find you weird probably, with your vegan and organic ways,. It doesn't matter. They've got hands on experience about some aspects that can save you years of experimenting. And be happy to talk to a young person interested in gardening.
Daikon might not like wet feet. Maybe horse radish would be better than fennel. The more biodiversity you bring in the more easy insect-control will be in the long run. If you save the seeds, it is cheaper and easier to get your hands on seeds of
local peat gardeners that have proven over the years. That's another way. Don't change the soil too much, change the germplasm. Local seedswaps might spur your project on.
Bio diversity will bring in birds and droppings, worms will love your soil, whatever your opinion on farming them. Mycelium running of
Paul Stamets, are you familiar with him?
My daughter is flexi vegan so i am familiar and sympathetic to the idea. It does make it harder to get
permaculture accepted by traditional farmers who see no harm in raising organic free range but that's how it is, People differ. Respect is a two way street. Lead by example etc.
It's up to folk themselves. Keeping
chicken's can be messy in small settings and time consuming. In an urban setting like Holland is, it's more relevant to get this veganic branch flourishing.
I am not saying you have to grow Alder trees, they do root down deeper and can take serious abuse in chop and drop. Check out what other trees grow. They're of no use in a crop wise sense. But yeah handy to create a "sun trap", microclimate. Good habitat for birds. But you could get a food hedge going as well to establish that. Hazel nuts, apples/ pears what have you. Look around which varieties do well on peat soil locally. Swap wintercuttings, grafting material for myceium. Everybody is fascinated by
mushrooms! World of veganic options!