There was a great cover article in the March 2014 edition of Graze magazine that I thought would be worth summarizing. The article was written by Gabe Brown, a grass-fed beef producer in North Dakota, who has gotten a lot of recognition lately for the innovative seed mixes that he no-till drills into his pastures - upwards of 30 species. His article answers the question, how do I seed into an existing pasture? He notes that there are successes when herbicides are used to set back the spring growth. However, for organic producers it will be extremely difficult to get the new crop established due to the competition from spring growth of cool-season perennials in a northern climate. So, drilling in the spring is not the best option.
Gabe outlines his method of seeding after the spring growth flush. Without the use of herbicides, Gabe relies on his livestock. He will graze an area hard the previous fall to weaken the root reserves going into winter. That spring he'll graze the area earlier than he might normally and graze it more often. This aggressive grazing will force plants to use up stored carbohydrates so they'll be less vigorous and not as competitive. Once the peak of cool-season growth has passed, he drills in a warm season mix.
The example Gabe uses is a mix of sorghum-sudangrass, pearl millet, cowpeas, forage soybeans, brassica, tillage radish and sunflowers. He will also add some other species in small amounts to attract pollinators and beneficial insects. In subsequent years, he'll change the diversity and incorporate new species such as vetch, clovers, and chicory. The diversity of species, with varying root structures improves nutrient cycling, and by the third year, Gabe observed that the existing perennial plants appeared healthier. In his system for beef, the pasture mix will be grazed close to plant maturity with a high stocking density and half of the biomass will be left to improve soil health. This model is for beef grazing, but could be adapted accordingly to fit the dairy system.
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Beef grazing at Brown's Ranch |
Starting with even one warm-season species, such as millet, may be an option. Last season, we (the UVM Extension Crop, Soil and Pasture team) did trials with millet and other warm season species on three farms. However, extremely wet weather left us with less than desirable outcomes. The seeds likely drowned and rotted with all the rain we had in June and July. We plan to try no-till drilling millet and other warm-season species into pastures again this season, and hopefully we'll have some better results on clay soils to share with you later this season.
So what's another way to improve species diversity and pasture quality in late winter/early spring? The old stand-by, frost seeding is a better bet. It's relatively fool-proof if done at the right time and a great way to increase the percentage of clovers. We just finished a frost seeding trial with clover and forage chicory last week, so we'll have more on that to come too...
I'd sure love to hear your feedback on these ideas or others to improve pasture diversity and forage quality in our region. Email me at: [email protected] or call 802-388-4969 x 346.