I personally have no idea on how to grow fruit and vegetables but Fully believe that teaching kids to do so from a young age can help them in many ways.
1. Pride in work that they have been part in.
2. Patience, while waiting for their plants to grow.
3. Responsibility, looking after the plants for the best outcome.
4. Achievement, by taking the project from seed to table.
Learning a way to grow there own organic food either in the ground or planters or pots.
Learning about the planet and how to best look after it.
I believe such projects from a young age would benefit in so many different ways and you don't need a field.