Haying cover crops will generate more feed for livestock, and for grain producers, a source of income for the cover crop, while still targeting some of the issues of the soil and creating more feed diversity for the soil biology. In the wheat-canola rotation that seems to be in vogue presently, growing a cover crop high in legumes would give the opportunity to fix nitrogen for the next crop, minus the nitrogen that will be exported in the hay. By including some species with tubers, there is the opportunity to capture free nutrients deep in the soil profile, get stored in the tuber, and then released when the tuber rots. By having this legume crop in the canola-wheat rotation, it is a disease break, reduction in inputs of the cover crop year and the following year, spreads out the work load, and diversifies the operation. For livestock producers, having extra feed is always good. It can act as a bridge between taking a perennial hay production
out and getting the next field into production. In most cases they could be grazed, and the potential to have a different relative feed value feedstock. Harvesting the hay crop can be managed so it does not interfere with the perennial hay crop, either before or after.
Haying would lead to a higher grass content for easier dry down. Silage can accommodate a higher legume and broadleaf content. Millets, cereals, sorghum sudangrass, and teff all make good quality hay. Ryegrass can be hard to cut if it gets too mature. Fall cereals can offer an early cut of hay and has the potential for a second cut, especially with winter triticale. Care needs to be taken with sorghum sudangrass. If cut when under stress, the plant will accumulate prussic acid, which is a precursor to cyanide. It does dissipate naturally, if the plant is allowed to recover from drought or frost stress.
The other challenge with sorghum sudan is it will grow extremely quickly through July and August, where it can reach three to four meters (nine to twelve feet) tall. For easiest handling, sorghum sudan can be cut twice in the growing season, each time when it reaches one and a half meters (four feet). Ensure there is twelve to sixteen inches of stubble left to allow quicker regrowth. Silaging sorghum sudan has a lower risk for prussic acid residual. The key to managing silage is to leave the pile uncovered for a couple days to allow the prussic acid to gas off.
Broadleaf plants pose a bit of a challenge for hay. Most tend to be leafy and succulent, making dry down a slow process. Keeping the plant density low in hay situations is key, or look at silaging the crop. They help boost protein and feed value but the curing process will cause some stress. The other option to get the broadleaf in the growing season is to broadcast seed into the hay cover crop before cutting or seeding after harvesting the hay or silage using quick establishing species with good frost tolerance.
Legumes can fit into either hay or silage. Some species like red clover can cause dry down issues, but there are other options. Hairy vetch will overwinter and will continue fixing nitrogen the next year, as will sweet clover. Berseem clover is one of the highest annual clovers, but has coarser stems than crimson clover. Persian clover is lower growing but has some potential as a hay species. Once cut, Berseem, crimson and Persian will regrow. Where as mung beans and peas would be a single cut with minimal regrowth. Like grazing, tonnes come from the grass component, broadleaves would bring quality, and legumes would bring quality and fixes nitrogen. Choosing the blend used will be determined by the relative feed value requirements and how the crop will be harvested.
To help balance some of the nutrient export of the hay or silage, picking species that will regrow or have a large root system as either fibrous system or a tuber would be beneficial. Having the regrowth cover the soil will help protect the soil and give the earthworms something to chew on.