GHGMP News Releases
Research unearths benefits of proper manure application rate
Indian Head, Sask., September 7, 2004
When managed and applied properly, livestock manure can be a valuable and environmentally sound nutrient source for annual and perennial field crops, says a Saskatchewan researcher.
Dr. Jeff Schoenau, a soil scientist at the University of Saskatchewan evaluated a range of manure application, soil and environmental parameters at a number of sites sites across Saskatchewan over several years. Manure not only benefits soil and crops, but can be managed as part of an environmentally sustainable farming system, he says.
Schoenau's research has been supported in part by the federal Greenhouse Gas Mitigation Program for Canada Agriculture (GHGMP). A full regional report on the research can be found on the Soil Conservation Council of Canada's (SCCC) recently revamped Web site at www.soilcc.ca.
The key, says Schoenau, is to target proper agronomic rates. The rates must meet, but not exceed crop requirements.
"We find that excessive rates of manure - rates greater than what the crop can use year after year - and with applications year after year, we end up with high nitrate concentrations in the soil," he says. "With those treatments, we also see an elevated production of nitrous oxide, which is one of the more serious greenhouse gases."
When manure is applied at proper rates, says Schoenau, there is good crop response, no evidence of nutrient loading in the soil, no salt accumulation and no evidence of large losses to the atmosphere or leaching.
"Manure application technology has improved greatly in recent years," he adds. "There is a lot of good equipment on the market. In fact, Western Canada leads the world in manure application technology. Our low disturbance injection systems are compatible with zero-till production and can be used equally well with annual cereal and oilseed crops, as well as with forages."
Along with proper application rates, research also showed proper nutrient balancing is important to crop production. For example, different manure types will have different nitrogen and phosphorus availability. In the case of cattle manure, additional commercial nitrogen may be needed to help the crop use the phosphorus in the manure. Likewise, supplemental sulfur may be needed to match the high nitrogen level of liquid hog manure, says Schoenau.
The GHGMP supports a broad range of projects across Canada with the goal to promote awareness of agricultural practices that reduce greenhouse gas emissions. SCCC administers the delivery of the soil and nutrient management sector component of the program. For more information on activities, visit the SCCC's Web site at www.soilcc.ca.
For more information, contact:
Dr. Jeff Schoenau
University of Saskatchewan
Phone: (306) 966-6844
Doug McKell, P. Ag.
Executive Director, SCCC
Phone: (306) 695-4212