Complex sentence: When aerial seeding a cover crop one must seed them at least 7 to 10 days before drilled cover crops, the reason for this is because the aerial seeding method is slower than that of the drilled method.
Split into simpler sentences: When aerial seeding a cover crop one must seed them at least 7 to 10 days before drilled cover crops. The reason for this is because the aerial seeding method is slower than that of the drilled method.