Manure is a waste product of Agricultural Animal Farming used as a soil fertilizer for production of edible plants but many people have misconceptions about its application in the industry. In this how to we will go over some of the larger concepts behind its use. Which crops are grown with manure and whether those crops are for human consumption or animal feed. This information is based primarily on commercial farm use as there is not a lot of data covering home and hobby farms. Although you might not be a commercial farmer it is important to understand the industry because commercial farms are using best practice methods to obtain the highest returns and also to comply with standards for safe food production.
Of all of the crops grown in the USA only about 4% of them use Manure either raw or composted as a soil enhancement fertilizer. There are many reasons for this including cost but this small number of only about 4% of farms using Manure in their production of Crops has a lot of application to the home or hobby farmer.
There are nine major crops that are grown with manure in the USA including: Barley, Corn, Cotton, Oats, Peanuts, Sorghum, Soybeans, Wheat and Hay and Grasses for Animal Feed. Of those crops Corn is the primary product that is grown with manure accounting for about 60% of all acreage that manure is used on. The next highest crop is Soybeans which accounts for about 6% of all acreage. The next three crops that each account for about 2.5% of manure use are Cotton, Oats and Wheat. Manure is also used to grow grass and hay for animals and this accounts for about 25% of all manure use in the USA.
This means that of the 4% of farms using Manure about 75% of those crops are Corn, Soybeans, Oats, Wheat production and the rest of the crops that might see manure use all are under 1%. And then field grass and hay accounts for another 25% of manure use.
The next statistic will really bring into perspective the use of manure in farming.
Of all of the commercial growers using manure 52% of its use was on the animal farm that it came from. Dairy, Beef, Broiler Chicken and Hogs farms were the primary users and as we saw above about 25% was for Hay and Grass and another 60% was used for Corn. This is directly connected to the manufacturing of on site feed for Animal consumption. Many of the other crops such as soybeans are also used for Animal Consumption.
Although 52% of manure is used for on site animal food production there is also a high percentage almost equaling that which happens off site. Including hay and grass production which accounts for 25% of all manure use. The problem is that farmers that raise animals for consumption can not produce enough of it on site because they are primarily animal farmers. The farms that do produce their own animal feed will use all of the products in our list in their feed production with the exception of Cotton which is not consumed by animals or humans.
Animal Farmers will use Corn, Soybeans, Barley, Oats, Peanuts in their feed either directly or in food pellet manufacturing. Hay is stocked for winter months while grasses are grown for grazing in the growing season.
The cost of manure to the farmer is normally free with the exception of transportation. Animal farmers that grow feed crops on site do not have as high a cost to transport the manure if it is localized but it will limit its use on larger farms.
Overview Of Manure Use In Agriculture
Even though manure is free and the cost of manufactured fertilizers is high the use of manufactured fertilizers is preferred by commercial farmers. There are a few reasons for this including: food production safety, the ease of application and a uniform product that can be adjusted to meet the chemical properties needed by different crops.
Manure can vary in its nutrient properties and a good amount of it is required per acre. Commercial fertilizers may often use animal or human waste as their source of chemicals but they are treated and produced in controlled treatment plants where the levels of bacteria, heavy metals and pathogens that can make humans sick can be monitored or eliminated. Treatment plants that convert waste to fertilizer also often only produce it for non crop use such as landscaping, golf courses and commercial use that is not concerned with food production.
Final Note
Of the farms that do use Manure for crops that can be consumed almost all of it is directly related to food produced for animal consumption. Remember only about 4% of all crops in the USA are grown with manure on any commercial farm and about 50% are grown directly on Animal Farms and the remainder is used for hay or feed production. About 60% is used for corn and 25% used for hay and grass production. The other crops grown are primarily supplemental animal food crops.
Can manure be used by farmers for crops that are consumed by humans?
Yes, manure has been used historically and especially before pelleted and granular forms of fertilizer were available. However that does not mean that it is the best or even a good choice for farms producing food for human consumption.
The dangers of pathogens is a real problem for the commercial grower and the home or hobby farmer. For example many nut producers such as walnut farmers use to allow goats or sheep to graze in their orchards to reduce grasses around their trees. They found that when the nuts fall to the ground they were being contaminated by the waste from the animals and the practice has stopped. You will also find that commercial nut, olive and fruit tree growers will now place large tarps under their trees during harvesting to reduce this risk and to allow for easier collection when tree shakers are used to shake the nuts from the trees.
Federal Regulations have influenced farmers use of manure on about 30% of farms because manure is not regulated for runoff chemicals into streams and water bodies like commercial chemical fertilizer but on almost 80% of farms that say they moved away from manure use the main reason was Nitrogen and Phosphorous Levels required by the crops they are growing.
Manure can not be counted on for its chemical properties. Commercial Fertilizers can be manufactured to provide the exact amounts of Phosphorous, Nitrogen and Potassium levels needed for a specific crop.
So is manure a good choice?
Maybe if you are growing food for animals that you are raising on your property but for the most part the problems of using manure have resulted in it being replaced by commercially manufactured fertilizers.
I can hear people thinking I want to do things the old way. Well only a few hundred years ago there were no sewer systems and that resulted in plagues and massive numbers of dead. It wasn’t until recently that we started using antibacterial soaps and products to kill pathogens in our homes.
So you really need to take everything into account and say you are moving into the 19th century and begin using products that are safer for you, your family and if you sell produce from your farm for the community you serve.
Some of this information including statistics and percentages were obtained from the USDA ARMS Data.