By Mary Wicks
Did you know that manure is a valuable resource? From applying it to cropland to creating compost, it can benefit crops and soil or generate additional income. Using manure is complex, which makes it interesting but challenging. There are many factors, such as nutrient availability, application methods, and application rules that need to be taken into account.
A recent 2-year study by the University of Wisconsin compared the effects manure and inorganic fertilizers on soil health. Researchers demonstrated that manure was more effective in maintaining soil pH at a healthy range, while the fertilizer tended to increase acidity. Manure was also more effective in increasing total nitrogen in the soil. And, due the organic matter in manure, it helped increase water stable aggregates, which makes soil more resistant to erosion. However, the electrical conductivity of soils with manure application was higher, indicating that salt levels in manure need to be considered.
The key for land application is to take advantage of the nutrients in manure, saving money on fertilizer while also protecting water quality. Following the 4R Nutrient Stewardship principles (right source, right rate, right time, right place) is a good starting point, but other considerations, such as weather and storage capacity, must also be addressed.
In Ohio, nearly 49% of manure is applied from October to December, but an unusually wet fall followed by an extended wet spring as we are currently experiencing, can limit the days available for field application. This results in many livestock producers with not enough manure storage capacity. Regulations that limit manure application during winter months and rain forecasts that prevent manure application can further reduce the application window. To expand the available days for applying manure, Glen Arnold, manure management systems field specialist with OSU Extension, has shown that using liquid manure to side dress emerging crops, especially corn and wheat, can result in yields similar to, or better than, commercial fertilizers.
Manure can also be a source of income. Poultry litter is often sold to crop producers as a source of nutrients and to improve soil tilth. Others compost manure for sale to nurseries or garden centers. Composting is a natural process in which organisms, primarily microbes, decompose the manure. When managed correctly, this aerobic process can reduce pathogens, odors, and the moisture content creating a product that is easier to handle and allows manure nutrients and organic material to be cost effectively transported off the farm.
Learn more at the Manure Science Review
There’s a lot more to know about managing manure and the Manure Science Review on August 7 is a great place to learn. This year’s speaker and demonstration program will be held at JIMITA Holsteins in Strasburg, Ohio, and then followed by a tour of nearby Bull Country Composting. Speakers will address when manure nutrients are available, what cover crops can and can’t do, side dressing with manure, and more. Field demonstrations will highlight spreader calibration, liquid manure application methods, manure health, and other practices. The day will wrap up with a tour of a commercial manure composting facility, focusing on material handling and processing as well as marketing.
This educational program qualifies for continuing education credits for Certified Crop Advisors, ODA Certified Livestock Managers, ODA Fertilizer Recertification, Pennsylvania Manure Hauler/Broker, and Indiana State Chemist Category 14. For program and registration details, click on the link at https://ocamm.osu.edu/.
Mary H. Wicks, Department of Food, Agricultural and Biological Engineering. Phone: 330.202.3533. E-mail: firstname.lastname@example.org. This column is provided by the OSU Department of Food, Agricultural and Biological Engineering, OSU Extension, Ohio Agricultural Research & Development Center, and the College of Food, Agricultural and Environmental Sciences.