The use of cover crops is one of the most positive practices in agriculture. The range of species that can be used for this purpose is almost endless. The capabilities of these plants range from their abilities to substitute for tillage to the fixation of nitrogen and conservation of nutrients and water. Many of them can be utilized as forage crops for extra income in the winter months, allowing for recycling of nutrients and improved profits from every acre.
In March I attended the Oklahoma No-Till Conference, and I heard presentations about crops and practices that are very different from this area. I came away with some valuable ideas, one of which is that cover crops are well worth the effort and expense required for their establishment.
Another was that their research has shown the most profitable systems are those which include cover crops combined with grazing animals.
We have utilized a similar system here with high biomass wheat varieties being grazed through the winter months and then killed with herbicides prior to planting the summer crop. Cattle may be removed early so the wheat can be harvested for grain.
Some of this wheat has yielded as well as non-grazed fields while providing abundant forage for cattle into the month of February. This was not a good wheat year overall, but some who used this system received more benefit from forage production than from grain.
Cover crops like wheat offer several advantages for improving soil productivity. Among these are the conservation of nutrients and water. The plants prevent their movement downward and away from the primary root zone. Then as the wheat plants and their roots decompose, these nutrients are released back into the soil solution for use by the summer crop.
Wheat roots also penetrate compacted soil layers during the winter months when the more dense soil softens. The following summer crop roots are then able to follow the old root channels through the compacted zone to reach the deeper sources of nutrients and water that would otherwise be unavailable to them.
Since wheat is a host crop for beneficial mycorrhizae, these beneficial fungi quickly colonize the roots of summer crops to aid in uptake.
An added benefit of cover crops like wheat is that they provide a mulch effect to suppress the germination and emergence of weeds. Growers have been amazed to find this mulch capable of preventing the emergence of herbicide-tolerant weeds. This alone is a major benefit in areas where weed resistance is a major problem.
Another big advantage can be seen today in fields around the area in which cover crops were planted. These fields are tolerating the heat and drought stress better than nearby fields that had no cover. There are several reasons for this, but I would need another 40 pages to get into that. I will just say it works and leave it at that, after all that’s enough.
It looks like we may be finishing this crop earlier than expected because of the accelerated drying effects of heat and low humidity levels.
Many fields were left unplanted this year due to excessive rains in the spring. These fields should be planted to cover crops this fall to protect the soil and prepare them for higher yields next year. Volunteer plants such as annual bluegrass and many other species are helpful in conserving the soil, but many of them such as henbit are host plants for nematodes. Neither do they offer the nutrient recycling and mulching effects of a cover crop like wheat.
Cover crops are a “win-win” situation for the land and for profitability.