The More the Merrier When It Comes to Pastures
Written by Ev Thomas and Dan Wiersma*
|Select the Right Species||Improving Existing Pastures||Even Pastures Need a Rest|
The quality of pastures on dairy farms varies widely. Some pastures are simply fenced-off areas that, for various reasons, are unsuitable for other crops. These pastures receive little or no active management — no lime, fertilizer, or reseeding — and are continuously grazed with no separation into individual paddocks.
These pastures provide some early-season forage — often dominated by native grasses and weedy species — but the combination of warmer, often drier weather plus overgrazing soon takes its toll. By midsummer, the livestock in these pastures usually need to be supplemented with hay or silage.
Modern pasture care includes seeding an improved species mixture (using either conventional tillage or no-till practices), applying lime and fertilizer as recommended by soil analysis, and constructing fencing systems to permit rotational grazing.
Select the Right Species
When it comes to forage species selection for pastures, the more the merrier! Research has shown that a combination of species (and different varieties within a species) results in higher yield and quality under varying conditions.
A single species can perform very well under a specific set of weather and soil conditions. For instance, cool-season grasses often excel during early spring when soil conditions are cool and moist. By midsummer, the growth of these grasses typically has slowed, but legumes such as white and ladino clover remain productive.
One university trial involved the seeding of various combinations of grasses and legumes in replicated plots, then observing their performance throughout the grazing season. Included were single species and seed blends consisting of up to 10 species and varieties. The conclusion: The more forage species and varieties included in the seed mix, the more consistent the yield and quality from spring through fall.
While we often recommend that farmers mix their own alfalfa-grass blends to allow variety selection within the species (for instance, using a late-maturing orchardgrass with a leafhopper-resistant alfalfa), many of the pasture mixes sold by seed companies contain an assortment of pasture species. For instance, one seed company’s product promoted for intensive pasture management contains no fewer than 11 species: alfalfa, orchardgrass, reed canarygrass, meadow bromegrass, red fescue, meadow fescue, bromegrass, perennial ryegrass, Kentucky bluegrass, white clover, and ladino clover. Whew!
Improving Existing Pastures
Sometimes land is used as pasture because it can’t be economically used for anything else; it’s either too stony or too hilly to be part of the farm’s crop rotation. But even these pastures can be improved with the combination of fertilization and clipping. Some 1950’s research at the University of Maine involved native pastures that had never been tilled or seeded. It was found that by applying nitrogen fertilizer in the spring and then clipping the pastures following grazing, not only would the existing species become more productive (and, therefore, amount to a higher proportion of yield) but a long-term “botanical shift” would occur.
The use of nitrogen fertilizer favored the higher yielding species, which over time became competitive to the lower yielding species, in some cases crowding them out. Therefore, the combination of fertilization and clipping resulted in both short-term and long-term improvements in the yield and quality of these native New England pastures.
Even Pastures Need a Rest
Today, most pastures are actively managed, including the establishment of productive species that are then harvested by the use of rotational grazing. Rotational grazing is the practice of moving livestock between pastured areas (also called “paddocks”), either according to the amount of forage remaining in the paddock or by allowing the animals a certain amount of time in each paddock.
Rotational grazing results in one paddock being grazed while the remainder of the pasture area recovers. Systems that are based on rigid time schedules aren’t as good as those based on the growth of the forages in each paddock.
Compared with continuous grazing, rotational grazing results in more consistent production, higher forage yields, and often fewer weeds. Why fewer weeds? Turning a relatively large number of cattle into a relatively small paddock area often means that they will be less selective in the species they graze. Some rotational grazing systems involve moving cattle to a new paddock every day. This is more common with lactating cows because of the high-quality forage needed by these animals.
Manage your pastures by planting multiple grass and legume species of improved varieties. Then enhance pasture performance with fertilizers, clipping, and rotational grazing practices.
*Ev Thomas is retired from the William H. Miner Agricultural Research Institute and president of Oak Point Agronomics Ltd. Dan Wiersma is the alfalfa business manager with DuPont Pioneer.
Used by permission from the November 2016 issue of Hoard’s Dairyman. Copyright 2016 by W.D. Hoard & Sons Company, Fort Atkinson, Wisconsin.