TEN YEAR-OLD FIELD STUDY YIELDING A WEALTH OF INFORMATION ON MANURE MANAGEMENT
By Christine Rawluk, National Centre for Livestock and the Environment, University of Manitoba
The NCLE (National Centre for Livestock and the Environment) Long Term Field Laboratory was established in 2007 to initially answer ‘what happens to nitrogen availability and soil phosphorus levels over time when manure is applied either annually, at rates to meet crop N requirements, or intermittently, at rates to match crop P removal for several years?’.
After eight years, a couple more questions were asked, including ‘what is the capacity of the soil to continue to provide nitrogen if manure applications stop?’, and ‘how does suspending manure application impact drawdown of soil test phosphorus levels?’
Site experimental design: The 43 acre (17 hectare) field laboratory consists of a total of 96 66 ft x 66 ft plots under either an annual cropping system or a perennial forage-based cropping system. Each plot received either annual or intermittent applications of liquid pig, solid pig and solid dairy manures from the University of Manitoba’s Glenlea Research Station’s swine and dairy production facilities, as well as synthetic fertilizer and control (no fertilizer) treatments for comparisons. In 2015, select plots were split to accommodate additional fertility treatments, resulting in an increase to 144 plots. The site is located at the University of Manitoba’s Glenlea Research Station, 18 km south of Winnipeg.
What have we learned?
This long term field study is generating new agronomic and environmental sustainability information pertaining to manure management. The following are key findings to date for the annual crop rotation receiving yearly additions of manure or fertilizer for 8 of 10 years. Project leads for this phase of the research were Don Flaten, soil fertility professor (Don.Flaten@umanitoba.ca) and Trevor Fraser, soil science technician.
Nitrogen (N) fertility
Phosphorus (P) fertility
Getting the information out
Lessons in learnings and knowledge transfer at the NCLE Field Laboratory take many shapes, depending on the audience. Numerous field days, workshops, clinics and tours over the years have attracted producers, agronomists, regulatory and extension specialists, university students and professors, and special interest groups. These sessions cover the latest understandings of manure management practices for optimal crop productivity and minimal environmental risk and are often paired with sessions on other production and sustainability-related topics.
Reaching city and rural students: We have also developed specialized educational programming for high school students to broaden their understanding of the role of livestock as nutrient recyclers in producing food that is both economically and environmentally sustainable. Students get their hands dirty as they learn to think more holistically about our shared food system. We explore how manure management practices developed through science-based research are providing both solutions to environmental challenges as well as environmental benefits in the context of our shared food system, making the connection that protecting our resources is a shared responsibility.
At the end of their ½ day program their learning is put to the test to identify manure and land management practices we can use to improve nutrient recycling, soil health, productivity and overall sustainability of farming systems.
Research continues to break new ground
Now in its 12th year, the focus continues to be around the capacity of the manured soil to continue to release plant-available nitrogen, phosphorus and other essential nutrients and how this affects crop yield. Additionally, we are measuring nitrous oxide emissions from select treatments to gain a better understanding of the role of soil nitrogen transformations in generating this potent greenhouse gas. Project lead for this phase of the long term research is Mario Tenuta, soil ecology professor (Mario.Tenuta@umanitoba.ca). It is only because of this history of combined investment of research expertise, funding, and most importantly time at this long term site that we are able to answer these questions and to continue to ask new questions.
Acknowledgements: The NCLE Long Term Field Laboratory has received funding support from multiple sources since its establishment in 2007: Canada Foundation for Innovation, Manitoba Rural Adaptation Council, Agri-Food Research & Development Initiative, Manitoba Livestock Manure Management Initiative under the Canada and Manitoba governments through Growing Forward 1 & 2, a federal-provincial-territorial initiative, Agriculture and Agri-Food Canada Agricultural Greenhouse Gases Program, as well as Manitoba Pork Council and Dairy Farmers of Manitoba. Thank you.
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