Question

why should the seeds be sown at equal distances

Answer 1

to grow properly and mineral get

Answer 2

Seeds are sown by keeping at least equal distance among all of them, because when they grow into saplings, they require sun, rain and adequate amount of food and minerals so that their branches can grow equally in all directions.

When the seeds do not have ample space between them, they do not grow into full plants, as they have to compete for food and water.