The farm itself is located in Northwestern Illinois, and our farm year cycle runs about from March to March for grain operations.   March is when we do mechanical prep work on equipment, repairs of any overwinter damage (rodents, birds, etc.) and generally get ready for field work. 
In April as soon as the weather allows field work starts.   We practice No-Till at the Rottweiler Ranch, but some level of erosion damage happens ever few years so those repairs are made 1st.   The grain farming alternates corn then soybeans rotate on a yearly basis, and the field work is a little different for each.   Starting in 2017 we started growing some of our own hay, and that again is a different operations.   Corn is planted between April 10 and June 10, weather permitting.   Soybeans are planted about a week later, but just dry fertilizer is applied for soybeans to supply P  & K while with corn we have to add N (Nitrogen).  Left is an Anhydrous Ammonia application. 
Planting is done as soon as the soil tempature gets warm enough and the moisture is right.  We plant corn in 30 Inch rows, soybeans in 15 Inch rows.  Yes, GPS guidance is used it reduces waste and saves time!    Same with fertilizer and later herbicide application.  
Hay seeding isn't done every year, but when we do that we use a grain drill (which in 2017 Grant managed to get throughly stuck).  Grain drills have much narrower spacing than planters, but they are not as accurate with seeding rates(pounds per acre or seeds per acre), or seed placement (depth that the seed is placed in the ground).  The  drill is also used in the fall to apply a cover crop when appropriate (wheat, rye or barley) that is killed in the spring.  Cover crops help greatly with soil retention, organic matter, fertilizer scavaging and weed control.  Again GPS guidance is used to save time, and reduce waste.