Agriforestry is the integration of agriculture and forestry.
Kirsten Jurcek and her mother, Weenonah Brattset, graze cattle on their Jefferson County farm. This year, in partnership with Casey Dahl, they are establishing a 10-acre pasture area that will be known as a "silvopasture".
During a pasture walk at the Brattset farm recently, Dahl explained how he plans to establish working trees with forage in order to maximize return from the parcel of land.
Dahl is leasing the parcel and planting trees that are spaced to allow light to reach the forage. Once the trees are established, cattle will graze among the trees.
He says, "Heat stress in pastures can be a problem but this will help. If there is one lone tree in a pasture the cattle congregate under it and kill the vegetation below. With this system, they move around, enjoying the shade while they graze."
He notes, "In systems that have been established, the cattle have actually increased their rate of gain with a system like this."
TREES AND FORAGE
The system is planned to provide 40-50% shade for the forage plants.
Dahl says, "Plants like light but there is a photosynthesis saturation point. If a plant is over-stimulated by too much light and heat the plant's metabolism will shut down."
There are areas in the country that raise trees for lumber production but Dahl has chosen to raise trees that provide products for niche markets.
Chestnuts and hazelnuts work well with this type of system.
He worked together with Jurcek planning the system. In the first years of growth the Jurceks will do mechanical harvesting of the forage to allow the trees to get established. To do this, spacing between the trees is established to allow the equipment to fit.
He says, "Once the trees start getting taller we will cut the lower branches of the tree. That helps the tree's production and the cattle can't reach them."
Dahl says he has seen some successful systems that also utilize pigs to clean up fallen nuts or fruit under the trees. This is helpful because fallen fruit often results in insect problems if stays on the ground under the trees.
He says, "Worms and pests multiply in fallen fruit and become an even greater problem the next year."
He cautions, "When using pigs you will need to put a ring in their noses to keep them from rutting up the pasture. Then you may need to create a wallowing system so they will stay cool."
He is planting the trees into an established, healthy pasture. He tilled six foot strips 20 feet apart. If smaller equipment is used for mowing it the trees could be a little closer together.
He uses deer tubes to protect the young trees. He suggests, "Make sure the tube is vented. A solid tube in an open field will cook the tree."
He said, "I prefer the type with smaller vent holes spaced closer together. There are some available with fewer bigger holes but bees can get into the tube then and get trapped."
He will establish the hazelnut trees six feet apart in the row. Chestnuts should be 20 feet apart. Because of the spacing, the cost of establishment will be lower but he said it will be important to look at how the nuts will be marketed and determine which will return the greatest profit.
He is planting a new hybrid hazelnut that crosses trees from this area with the European variety. He points out, "Seventy-five percent of the hazelnut production comes from Turkey but those varieties aren't hardy enough to grow here."
The Midwest Hazelnut Association, made up of growers and researchers, is working to develop more hybrids for the Wisconsin climate.
He adds, "With this new variety we will pick the nuts off the bush rather than wait for them to fall to the ground. The nuts are ripe before the husks fall off."
He said hazelnuts grow in clusters of 5-15 nuts. The researchers are also working to develop varieties that will increase the number of clusters on each bush.
Both Dahl and Jurcek are enthusiastic about their 10-acre experiment.
In areas of the country where this method has been used, the farmers find the forage or agricultural crop grown in the rows between the trees provides an annual income while the trees produce a long-term income. The type of tree and the crop grown in conjunction with the trees varies according to climate and niche markets.