|Managing Cover Crops Profitably, 3rd Edition | | | |
| |Although typically grown as a cash grain, winter wheat can provide most of the cover crop benefits of other cereal crops, as well as a grazing option prior to spring|
| |tiller elongation. It’s less likely than barley or rye to become a weed and is easier to kill. Wheat also is slower to mature than some cereals, so there is no rush |
| |to kill it early in spring and risk compacting soil in wet conditions. It is increasingly grown instead of rye because it is cheaper and easier to manage in spring. |
| |Whether grown as a cover crop or for grain, winter wheat adds rotation options for underseeding a legume (such as red clover or sweet-clover) for forage or nitrogen.|
| |It works well in no-till or reduced-tillage systems, and for weed control in potatoes grown with irrigation in semiarid regions. |
| |[pic] |
| |BENEFITS |
| |Erosion control. Winter wheat can serve as an overwintering cover crop for erosion control in most of the continental U.S. |
| |Nutrient catch crop. Wheat enhances cycling of N, P and K. A heavy N feeder in spring, wheat takes up N relatively slowly in autumn. It adds up, however. A |
| |September-seeded stand absorbed 40 lb. N/A by December, a Maryland study showed (46). As an overwintering cover rather than a grain crop, wheat wouldn’t need fall or|
| |spring fertilizer. |
| |A 50 bushel wheat crop can take up 20 to 25 lb. P2O5 and 60 lb. K2O per acre by boot stage. About 80 percent of the K is recycled if the stems and leaves aren’t |
| |removed from the field at harvest. All the nutrients are recycled when wheat is managed as a cover crop, giving it a role in scavenging excess nitrogen. |
| |“Cash and Cover” crop. Winter wheat can be grown as a cash crop or a cover crop, although you should manage each differently. It provides a cash-grain option while |
| |also opening a spot for a winter annual legume in a corn>soybean or similar rotation. For example: |
| |[pic]In the Cotton Belt, wheat and crimson clover would be a good mix. |
| |[pic]In Hardiness Zone 6 and parts of Zone 7, plant hairy vetch after wheat harvest, giving the legume plenty of time to establish in fall. Vetch growth in spring |
| |may provide most of the N necessary for heavy feeders such as corn, or all of the N for sorghum, in areas northward to southern Illinois, where early spring warm-up |
| |allows time for development. |
| |[pic]In much of Zone 7, cowpeas would be a good choice after wheat harvest in early July or before planting winter wheat in fall. |
| |[pic]In the Corn Belt and northern U.S., undersow red clover or frostseed sweetclover into a wheat nurse crop if you want the option of a year of hay before going |
| |back to corn. With or without underseeding a legume or legume-grass mix, winter wheat provides great grazing and nutritional value and can extend the grazing season.|
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| |[pic]In Colorado vegetable systems, wheat reduced wind erosion and scavenged N from 5 feet deep in the profile (111, 114). |
| |[pic]In parts of Zone 6 and warmer, you also have a dependable double-crop option. See Wheat Boosts Income and Soil Protection. |
| |Weed suppressor. As a fall-sown cereal, wheat competes well with most weeds once it is established (71). Its rapid spring growth also helps choke weeds, especially |
| |with an underseeded legume competing for light and surface nutrients. |
| |Soil builder and organic matter source. Wheat is a plentiful source of straw and stubble. Wheat’s fine root system also improves topsoil tilth. Although it generally|
| |produces less than rye or barley, the residue can be easier to manage and incorporate. |
| |When selecting a locally adapted variety for use as a cover crop, you might not need premium seed. A Maryland study of 25 wheat cultivars showed no major differences|
| |in overall biomass production at maturity (92). Also in Maryland, wheat produced up to 12,500 lb. biomass/A following high rates of broiler litter (87). |
| |In Colorado, wheat planted in August after early vegetables produced more than 4,000 lb. biomass/A, but if planted in October, yielded only one-tenth as much biomass|
| |and consequently scavenged less N (114). |
| |If weed control is important in your system, look for a regional cultivar that can produce early spring growth. To scavenge N, select a variety with good fall growth|
| |before winter dormancy. |
| |Wheat Boosts Income and Soil Protection |
| |Wheat is an ideal fall cover crop that you can later decide to harvest as a cash crop, cotton farmer Max Carter has found. “It’s easier to manage than rye, still |
| |leaves plenty of residue to keep topsoil from washing away—and is an excellent double crop,” says Carter. |
| |The southeastern Georgia farmer no-till drills winter wheat at 2 bushels per acre right after cotton harvest, without any seedbed preparation. “It gives a good, |
| |thick stand,” he says. |
| |“We usually get wheat in by Thanksgiving, but as long as it’s planted by Christmas, I know it’ll do fine,” he adds. After drilling wheat, Carter goes back and mows |
| |the cotton stalks to leave some field residue until the wheat establishes. |
| |Disease or pests rarely have been a problem, he notes. |
| |“It’s a very easy system, with wheat always serving as a fall cover crop for us. It builds soil and encourages helpful soil microorganisms. It can be grazed, or we |
| |can burn some down in March for planting early corn or peanuts anytime from March to June,” he says. |
| |For a double crop before 2-bale-an-acre cotton, Carter irrigates the stand once in spring with a center pivot and harvests 45- to 60-bushel wheat by the end of May. |
| |“The chopper on the rear of the combine puts the straw right back on the soil as an even blanket and we’re back planting cotton on June 1.” |
| |“It sure beats idling land and losing topsoil.” |