We talk about Mycorrhizal Fungi like its our best friend but how much do we really know. Take the time to read this article on Mycorrhiza and what it means to have a viable colonization in our soils.
Your crop roots only touch 1-2% of the soil profile. Luckily, we have help from billions of living organisms within the soil. In fact, just one cup of soil has more bacteria and fungi than there are people on the earth. Mycorrhizal fungi (MF) are a beneficial fungus that colonizes plant roots, extending filaments called hyphae out as far as two feet past the root system, which dramatically improves water and nutrient uptake for most crops. MF are found in natural ecosystems all over the world, but are absent in most croplands because their populations will die if deprived of a living root host for longer than a few weeks and tillage is very destructive to MF populations. Most cropland has been historically managed in a manner that included annual crops with root systems that die at maturity, with long fallow periods in between crops. MF can provide numerous benefits, including:
Drought tolerance: The extensive hyphae network of MF provides a much more efficient moisture gathering network. Research from the University of Wisconsin-River Falls demonstrated that MF inoculated plants survived without water 30% longer than untreated plants.
Better nutrient availability and uptake: The hyphae of MF can actually exude chemicals that have the ability to bore microscopic mining tunnels into tiny pieces of soil minerals and extract valuable plant nutrients. Research also indicates that plants with good colonization of MF show a large improvement in uptake of immobile nutrients, particularly phosphorus and zinc. MF also reduces iron chlorosis due to better iron uptake in high pH soils.
Salt tolerance: MF can absorb salt and move it into little capsules where it is sealed off and kept out of soil solution. Research has shown inoculated onions (a very salt sensitive plant) yielded 17 times more than uninoculated onions in salty soil.
Weed control: Many weed species, such as pigweeds, are not colonized by mycorrhizal fungi and do not benefit from them, but MF makes the roots of colonized crops much more competitive against the weed roots. A North Dakota State study showed a 54% decrease in weed biomass in a crop of sunflowers when inoculated with MF.
Improved soil structure: MF secrete a compound called glomalin, which is a powerful and long-lived soil aggregating agent. This soil glue is a powerful soil building agent and give soil great resiliency. Combining MF inoculation with no-till and cover crops can create dramatically improved soil structure in a surprisingly short period of time.
It is now easy to realize the benefits of mycorrhizal fungi, as there is commercial inoculant available. Green Cover Seed carries MycoApply inoculant, which contains four species of mycorrhizal fungi. It can be applied to either cover crops or cash crops. Cover crops can also be used to maintain MF populations between cash crops and further extend the benefits from a single inoculation over several crops.
Green Cover Seed can blend MF inoculant right in with your cover crop seed order. The spores remain viable for up to two years on the seed, are not adversely affected by sunlight and tolerate temperatures up to 120 F without harm. MF and cover crops are a perfect combination for improving soil function, particularly on more difficult soils.
One of the most widely reaped benefits of cover crops is providing valuable supplemental forage to grazing animals. Well planned annual cover crop mixes can provide highly nutritious available forage when perennial grass pastures are either unproductive, poor in quality, or in need of rest. The most critical period for perennial pastures is the month prior to fall dormancy and grazing cover mixes and providing rest during this period can greatly improve the long term performance of permanent pastures.
Cover crops can provide quality grazing when grass pastures are of low quality, such as late fall when native grasses are poor quality or early spring before native grass greens up. Most of the production from a perennial grass pasture occurs in the first half of the growing season, while most of the forage demand in a spring calving herd occurs in the last half of the growing season. Incorporating cover crops into a pasture program can provide a sequence of quality forage that can produce excellent animal performance for as much as twelve months a year and eliminate the need for hay or other stored feed.
This can be particularly useful for a grass finishing operation which needs a constant supply of high quality forage, for grass based dairy operations, or for any livestock owner that wants to maximize performance and minimize costs. The cost per ton of feed from a grazed cover crop is usually far less than the cost of hay or silage.
For example, a grazing program can utilize native warm season grass in May, June, and July. Using native grass for just this short period is called intensive-early stocking. This allows a doubling of the season long stocking rate, uses the grass at its peak forage quality, and also allows a rest during the critical period prior to dormancy. Animals can then be moved to a cover crop blend of summer annuals like BMR sorghum-sudangrass and cowpeas for August and September, then transferred to a blend that utilizes cool-season covers like turnips, radishes, oats, spring peas, and spring barley. This can be pastured through fall and then the herd can be moved to corn stalks that have been aerially seeded to rye. This can often allow grazing throughout the winter and spring, especially if strip grazed to ration out availability of spilled grain throughout the winter. Presto! Twelve months of grazing; no hay needed. This is only one set of options among many. There are unlimited cover crop options for providing grazing at different times of the year. See the catalog sections on Spring, Summer and Fall Mixes for some examples.