As its name implies, roughly half of the grain area in the spring wheat region is sown to spring wheat. Spring barley and oats are the other major grains. A seven-year rotation would likely include an additional year of wheat and an additional year of barley or oats. Some rotations may incorporate four consecutive years of wheat. The length and sequence of the rotation may vary, but the selection of crops is fairly limited.
Some researchers question the value of including a fallow slot in the rotation.
Most farm directors continue to include a fallow year, however, claiming that the subsequent wheat crop benefits from increased subsurface moisture. May. Of the spring grains, oats are sown first, followed by wheat, then barley. Planting is concluded by June. The crop advances through the reproductive stage during mid-July, when temperatures climb to their highest levels and grains are most vulnerable to heat stress. Barley is the first of the major grains to be harvested.