Rich in nutrients, cow manure fertilizes the land to grow crops for people and animals. Manure carries important nutrients that plants need like phosphorous and nitrogen. Cows depend on healthy crops to produce nutritious milk. In turn, those fields are nourished by the manure cows produce which is used as natural fertilizer. The crops are harvested to feed the cows, cow manure is created, and the cycle continues.
One cow produces 17 gallons of manure per day. That’s enough fertilizer to grow 56 pounds of corn or 84 pounds of tomatoes. On New England dairy farms, manure is a valuable resource to be reused instead of wasted, and it also reduces the need to use synthetic chemical fertilizers.
Some dairy farms across New England use anaerobic digesters to turn cow manure into renewable energy to power the farm and surrounding homes (see dairy farmers at Blue Spruce Farm in VT checking on their digester system in photo to the right). The digested manure on some farms is processed through a mechanical separator where they can use odorless solids (a by-product of this process) as clean, soft bedding for their cows rather than purchasing bedding from outside sources.
Dairy farms may also compost their manure and sell it to local businesses like vegetable farms and flower nurseries. Many dairy farms accept leftover food and food scraps that people and animals cannot eat and recycle them through composting and anaerobic digesters.
Every farm must abide by clean water laws. Farmers protect the water on and near their farms through a variety of practices to minimize potential runoff from their operations. Some farms use technology which allows them to shoot the manure underneath the soil, right were growing plants need it most and reduces the risk of runoff into local waterways.
New England dairy farmers work with state officials and agronomists to create nutrient management plans which act as a guide-map for the farm’s field work. Manure is spread on crop fields according to these detailed nutrient management plans. The plans are continually updated to reflect new technologies and take into account the types of soil on the farm, the terrain of the fields, soil moisture levels, and the amount of nutrients the next crop on that field will need.
The federal government offers incentives to help dairy farmers protect the water supply. For example, many farmers receive technical assistance when they upgrade their irrigation systems and manure storage facilities.