The value from manure comes in the nutrients provided along with other components that benefit soil health. Manure adds a layer of complexity to fertilizer management, but it also provides benefits to crops that commercial fertilizer on its own cannot provide.
Research helps with understanding the principles of how nutrients behave in different environments and provides insight to the impact of weather and soil conditions on improving efficiencies. With current high fertilizer prices and with the goal of improving soil health there are several components that will improve the economic benefits of manure.
- Managing nutrients with manure starts with knowing what you’re working with
- Importance of manure testing and soil testing; “if you don’t know where you’re starting, then how do you know where you’re going?”
- Importance of calibration of application equipment – improving uniformity (both spread pattern and constant rate), application width, minimizing compaction by awareness of field traffic patterns
- Maximizing nutrients – especially nitrogen by managing manure application rate, timing and placement with crop rotation, cover crops and equipment modifications
- managing supplemental commercial fertilizer requirements – timing and placement considerations as well as considering current field fertility levels
- Opportunities to move manure to fields with highest fertility needs or to sell manure or trade manure for straw etc.
- Using tools to fine-tune manure management and improve timing of nutrient availability and economics. (AgriSuite www.agrisuite.omafra.gov.on.ca , GPS/site specific/variable rate application etc.) AgriSuite tools such as the “manure calculator” provides an estimate of available nutrients based on manure analysis or database of values from similar livestock farms and management factors such as timing and incorporation details. Value based on available N-P-K equivalents, as well as total micro nutrients applied, will help with decision making for where manure nutrients can or will provide the greatest value. The newest tool, the greenhouse gas calculator, provides insight to the benefits of various management practices in reducing greenhouse gas on the farm.
The pdf provides an overview of some of the properties of manure and other organic amendments focusing on management practices that will help maximize the benefits of manure at the field scale