Each sowing machine differ types of seeds that can be planted
Wheat,barley,canola,oilseed,soy been,and grass
When you grow wheat or barley, you can get straw.
Oilseed is useful for fertilizer.
If oilseed will grow enough, you need to cultivate on oilseed.
And if you will get hay, you need to seed grass.
Sun flower,corn,soy been,sugar-beet
If you get corn or sun flower, you need to buy Headers matching Harvesters.
About sugar beet
If you get potatoes, you need to buy special Harvesters.
If you get potatoes, you need to buy special Sowing machine.
Additionally, you need to buy special Harvesters.
How to seed without cultivating
Some sowing machine can directly seed without cultivating.