Page "Seed drill" Paragraph 3

There are several downsides to this approach.

The most obvious is that seeds that land outside the furrows will not have the growth shown by the plants sown in the furrow, since they are too shallow on the soil.

Because of this, they are lost to the elements.

Since the furrows represent only a portion of the field's area, and broadcasting distributes seeds fairly evenly, this results in considerable wastage of seeds.

Less obvious are the effects of overseeding ; all crops grow best at a certain density, which varies depending on the soil and weather conditions.

Additional seeding above this limit will actually reduce crop yields, in spite of more plants being sown, as there will be competition among the plants for the minerals, water and the soil available.

Another reason is that the mineral resources of the soil will also deplete at a much faster rate, thereby directly affecting the growth of the plants.