Read the full report: Fertilizer value of manure
Design, construction and management of cattle feeding operations have evolved dramatically over the last 20 years. The quest for improved cattle comfort for consistent and predictable performance drove this process initially. Concurrently, changing regulatory climate towards greater environmental protection, particularly water quality protection by preventing or eliminating excessive nutrient or waste discharges to state or federal waters expedited development and adoption of new facility designs that would both provide cattle comfort for consistent performance and environmental protection.
Changing global economic conditions resulting from a biofuel-based economy and recent economic recession accelerated the need to make cattle feeding a more resource-efficient process. Taken together, these factors have contributed to attributing greater economic value to manure derived from cattle feeding operations. This, in turn, promoted closer evaluation of cattle feedlot designs that would capture greater manure value; thereby, achieving a better matched nutrient cycle between soil, plants and animals while preventing contamination of state and federal water resources.
One of the objectives of this manuscript is to provide an in-depth analysis of the impact of feedlot design on manure nutrient values to aid feedlot owners and managers in the decision to select a feedlot design consistent with their objectives for crop land and manure management. A second objective is to demonstrate the impact of the value of manure as fertilizer on corn production destined as cattle feed and to determine how corn grain, fertilizer and cattle prices interact to determine sustainability of the land, cattle, crop and manure system.
Much private engineering and consultant time and effort along resourceful and innovative thinking on the part of feedlot owners and operators has resulted in peculiar and effective adaptations implemented in feedlot designs of all types. The challenges of increasing input prices will continue to place pressure on feedlot owners and operators to generate solutions. Current expansion even in states with the strictest environmental laws is an indication of profit margins achievable in Upper Midwest states due to nearness to grains and forages and of appreciation for nutritive value of manure. Current expansion is also an indication of the understanding and willingness of entrepreneurial, self-started, highly motivated feedlot owners and operators to produce a safe and wholesome product while remaining the best stewards of land and cattle.
Differences do exist in capacity of each feedlot design evaluated to retain nutrients from manure; those on slatted-floors over a pit retaining the most nutrient value. In addition, at application rates to meet nitrogen needs of corn manure derived from all feedlot designs evaluated also supplied sulfur fertilization rates within recommendations for enhanced corn yields. Challenges will continue to exert motivational pressure on feedlot owners and operators and the allied industry that serves them. Because of various issues, there is no single feedlot design that is perfect for every situation.
This research can help direct cattle producers on design, construction and management of their feeding operations to effectively raise cattle along with gaining greater economic value to manure. The manure can be applied to corn and other crop fields for potentially enhanced yields.
Minnesota Corn Research & Promotion Council