The sod-based rotation shown in Figure 8.1 starts with two years of bahiagrass, followed by one year of peanuts, then one year of cotton: bahiagrass>winter cover>bahiagrass>winter cover >peanuts>winter cover>cotton>winter cover. When the rotation begins, there is a winter cover crop in the field; if it is being grazed, bahiagrass is overseeded into the cover crop. If it is not being grazed, the cover crop is terminated in March and bahiagrass is overseeded into residue.
This analysis used a Great Plains drill with a drill spacing of 7 inches, a seeding rate of 30 pounds per acre and a maximum seeding depth of one-half inch. Nitrogen is applied at a rate of 50 pounds per acre to bahiagrass and 100 pounds per acre to oats and rye. The grass is in place through the fall of the following year for two years of continuous bahiagrass. Winter covers are overseeded into bahiagrass when it goes dormant in October of the first year. When bahiagrass is grown it displaces a row crop in the rotation.
If fencing is installed, grazing can begin when the bahiagrass is established, 10–12 weeks after planting. In the fall, when the oat or rye cover crop is overseeded into the dormant bahiagrass, livestock are kept off the field for six to eight weeks until the cover crop is established.
In the second year, grazing on the cover crop continues until May. Then the bahiagrass comes back for summer grazing starting in June. In October and November, the bahiagrass is terminated with an herbicide, and oats or rye is planted.
In the third year, the winter cover is grazed until it is terminated three to four weeks before planting peanuts in May. Peanuts are harvested in October and November, and the winter cover crop is planted.
In the fourth year, the winter cover is grazed until it is terminated in March. Cotton is planted in April and May. The cotton is harvested in October and November, and the winter cover crop is planted. After the fourth year, the rotation begins again.
An economic model of the sod-based rotation is reviewed later in the chapter for a 200-acre farm. The farm is divided into four 50-acre fields. Each year, one field is in peanuts, one field is in cotton and two fields are in bahiagrass, with one field being grazed.