This is a superb idea but your going about it backwards.
First identify what the problem is.
If the problem is that farmers can't get a good market and are being screwed by brokers, then start an NGO.
If the problem is that I'm eating horrible food whose source may be the remanants of kileleshwa toilets, then you are in business.
I do agree that getting 100 farmers to agree on anything is impossible. I know I have tried with just 20. All of a sudden you start being told about the witchcraft so and so is doing.
What I'd ask is...f*** the being nice to farmers thing. Be nice to the consumer.
It's the consumer who's going to make your business, not the farmer. In fact, if you had as much land as 10 farmers, you probably wouldn't think about the other farmers.
So what does the consumer want. Then you will be able to find the farmers who are willing to do their best to give the consumer what he needs and their's your market and your money.
It seems you have a decision to make. Being an NGO or a business.
I can give you a platform if you wish. I did it with the thought of being nice. Now its abandoned but let's see if we can't work out something.
So I offer my online marketing skills to your idea. Condition being you stop being nice to people who steal fuel from a tanker. Just think of the consumer first.
Jose: If I make it through this thug life, I'll see you one day. The Lord is the only way to stop the hurt.