Mainly they aren't planting faster because those big planters cost so much, $250,000 is a lot of $$$$$! You can only justify buying so many of those machines. It's a balancing act between machinery cost and yield lose due to delayed planting.

Here is a link that might be useful: article direct link

Yup, I think that was part of the 'paradox" mentioned in the article. Smaller farms needed smaller equipment, and it even says we arent producing much more with "advanced" methods.

The cost of farm equipment is crazy. You need the larger tractors to be able to farm enough land to make a profit now. If you don't have enough land to farm the equipment costs are too much to make any money. My cousin farms around 4300 acres and uses a 24 row planter. It take a really large tractor to pull a planter that large.

Check out 'open source ecology'. They can build farm machines at 1/5th of what John Deere charges, and they are designed to last forever.