... the system will show approximate time of growing and how much it will worth (this price will include everything, starting from seeds, farmer job and ending with shipping).
So this would mean that people who are going to use your service will have to plan (or guesstimate) months in advance what vegetables they are going to need. This is why this won't gain traction on a large scale, especially since most people can barely plan a week ahead. You could counter this problem by installing some sort of marketplace where other people can put their vegetables up for sale. But then again why would people use your service when they can go to the supermarket and buy it there?
And If a user will agree and will pay, then he will receive access to his virtual part of the land, where he will see everything live (live stream, information about the growing process, what and how much was added during growing, and progress).
[...]
In the end, the user will get organic clean vegetables with 40 - 50% off from prices in supermarkets.
I really don't see how you are going to beat supermarket prices by 40 to 50%, especially since prices for vegetables are already pretty low since supermarkets buy in bulk and often times have very favorable deals with local farms. And when you're offering 24/7 live stream, which is a cool feature, but it's an expensive luxury for your model. Of course, as your model gains traction it will be easier to reduce costs but since I don't think it will gain much traction I feel like your model will be very expensive (initially).
I like the essence of your idea but the model as it is right now still needs some major tweaks before you can come close to making it into something that can actually succeed.