Pasture walk on Gerhls' organic farm
When it comes to grazing, Mike Gehl is insistent about a few things.
At least 10 percent of the total number of grazing acres should be set aside for sacrifice acres; pastures should never be over-grazed, even when feed is scarce; and a grazier should always be inter-seeding and replenishing pastures.
Gehl farms with his son Mike, grazing and milking a 40-cow herd and an additional 45 youngstock. Mike is also a certified grazing planner and assists farmers with the Milwaukee River Watershed with on farm technical grazing assistance.
The Gehls hosted a pasture walk on their organic farm on Tuesday, July 23, and explained overall organic dairy farm management and offered advice, based on experience grazing for the last 13 years. Gehl shared details of his successes and his failures.
Regarding the need for sacrifice acres, he said, "We're dealing with problems from the dry hot summer last year followed by the wet spring this year. By utilizing a sacrifice area and feeding some hay we allow our other paddocks to recover better and we concentrate areas of manure, distributing it here in the sacrifice area where it is needed."
Early in the season, February and March, he put the cows out onto another sacrifice area. There was some mud damage but the cows liked it, he said.
The end of May he loosened the top of the soil and seeded in pasja, oats and Italian rye grass. Pasja (pronounced facia) is a brassica that does not have a bulb like turnips have so cows cannot pull the bulb out and possibly chock on it.
Pasja creates a tap root. The cows can graze it short and then it re-grows. Six weeks later it is ready for more grazing. There will be oats mixed in for the first grazing but after that, it will be straight pasja or turnips.
He says, "We could have grazed it one week earlier. We used it only as a night pasture. Pasja is high in protein and the oats off-set it. There is a possibility that the pasja (or turnips or similar plants) could flavor the milk so we split feedings so they were only in it once a day."
Next spring he plans to treat other sacrifice pastures by replenishing them with orchard grass and Italian rye grass and maybe some wheat as a cover.
Dr. Guy Jodarski, DVM, Organic Valley, said, "Diversity in pastures is important. It's good to switch back and forth. Every plant provides different nutrients and it is important to have a balance because nutrients work together and one will make another more beneficial."
He also recommends measuring production and he demonstrated a simple way to determine how much production is in a given pasture in order to calculate the cow's daily consumption.
He simply makes a one-foot square piece and places it on the ground, then cuts the growth of plants within that square. He then weighs the growth with a gram scale: 450 grams per square foot is equal to 4300 pounds of production per acre.
Considering that cows don't eat all of it, he allows for one-fourth of the growth remaining but says, according to the measurements in Gehl's pasture, there is still three-ton of growth per acre that the cows are harvesting.
As a part of Gehl's attempt to have diversity in his pastures he established different plots with different mixes of grasses, legumes and brassicas.
Weeds are not an issue as long as the cows eat them, he said. Jodarski agrees saying, "The real definition of a weed is anything the cows won't eat."
He said cows will consume what their bodies are telling them they need and each species has a different supply of minerals. Burdocks are good for the liver. He suggests paying attention to what the cows are eating in order to determine if they have any ailments.
Jodarski also suggests that weeds are a symptom of a problem in the field such as compaction or mineral imbalance.
Thistles, according to Gehl, are a challenge. If a grazier is not organic, 2-4-D is the best solution. When organic, mob grazing will help but he says what is really needed is to interseed more grass and let the grass crowd out the thistles.
"That's why it is so important to keep interseeding whatever is missing in the mix in the pasture. If you don't, the weeds will fill in the space."
He solved the thistle problem by clipping when they come to a head. If they are allowed to grow in the pasture and be grazed but are not clipped they will continue to spread.
BENEFITS OF MINERALS
Another paddock area of the Gehl farm had a grass legume mixture that included plantain, a plant that is rich in net energy lactation, calcium and sulfur. Jodarski says sulfur is a key mineral because it has a negative charge to it.
Sulfur and boron will wash out because of the negative charge. It is necessary to make a true protein. The plant still accumulates nitrogen so the lab test will show it is high in protein but it is not a true protein. It needs sulfur to make it a true protein.
Even some weeds are high in sulfur so they may be more beneficial than one might think.
Brassicas are great sulfur accumulators, Jodarski says, so they are good in a pasture mix.
Jodarski adds, "All of this diversity we have seen here today is just on top of the ground. There is just as much diversity below the ground working for you. Plants take sunlight and put the energy from it into the roots and into the outside roots that are like a fungi attachment. It is important to feed these micro roots, the bacteria and the fungi."
Jodarski recommends doing wet chemistry on plant tests to determine whether there is sufficient sulfur and calcium. He said soil tests are important but plant tissue tests are also important.
He said palatability (tastiness) of a plant depends on the soil. Good soil will make plants taste better. He adds, "The same is true in your garden. Carrots are sweeter if they are grown on healthy, balanced soil. There will be different sugar levels in plants on different soil."
Throughout the walk Gehl stressed the importance of constantly interseeding the pasture. He said, "It should be a passion."
He points out that hard seeds such as clover can be interseeded at any time. One way to do it is mix it with the mineral mix and let the cows distribute it with their manure that acts as a medium for sprouting.
He says that won't work with grass seed, however, and he also doesn't recommend frost seeding grass seed because, unlike the clovers, it is a soft, not a hard seed. It needs to be seeded in summer when the soil is ready and warm. If it is cold and wet this soft seed will rot.
He also insists on the importance of clipping after grazing to set the stage for the regrowth. Clipping takes off any uneaten plants or weeds and headed out growth.
"And don't graze down to the ground. It destroys the root system," he says. "When clipping, cut a little higher, the level it would be grazed. Don't shave the ground."
In fields where he plans to harvest hay before grazing he likes to interseed alsike clover along with the mix because it dries at the same rate as the alfalfa.
He says interseeding is important because when working up a field to start over again, too much of the soil quality below ground is lost.
Finally, he suggests that dairy producers should not graze calves and young stock too long on a paddock. If they take it down below four inches the chances are too great that they will have a parasite problem.
While some graziers said their cattle want to eat all the way down, Gehl says "You need to train your cows. Move them off before they eat down too low and they will learn. If it is dry and you let your cattle go around the farm and hew everything down, it won't come back. You need to then give them feed in the sacrifice area so the other paddocks can revive."