A U of S project will compare fertilization, traditional manure application and variable-rate manure application
The University of Saskatchewan’s Livestock and Forage Centre of Excellence is looking into ways to make better use of an under-appreciated resource — manure.
Soil science professor Jeff Schoenau and his research team — also known as the poo crew — are in the second year of a five-year study trying to find the optimal methods of applying manure to a field.
“(Manure) is a valuable resource and when it is managed properly it could contribute to improved crop productivity, production and it can also contribute to improved quality of the soil by adding organic matter and nutrients,” says Schoenau.
The study consists of three test zones where different methods — fertilization, traditional manure application and variable-rate manure application — will be used to test the health and nutrients of the soil during the growing season.
“We will see how those different managements in time will influence nutrient levels in the soil and I guess especially how the precision management compares to the conventional management of manure,” says Schoenau. “The philosophy is that manure should improve the productivity of the soil. So in areas of low productivity, we increase the rate by 50 percent, in areas of high productivity we decrease the rate by 50 percent.”
Schoenau believes that getting the proper application rate is important because manure is not a perfect fertilizer and people tend to over apply it, sometimes leading to negative environmental impacts.
“(Manure) often doesn’t have the relative balance of nutrients that the crop needs. So that means to get the best benefit, it sometimes means supplementing with commercial fertilizer to make sure you have the best balance of nitrogen, phosphorous and sulfur,” he says. “If it is managed well, we can do that and at the same time minimize the adverse impacts on the environment by keeping the nutrients in place and preventing them from escaping to the water or to the atmosphere.”
Schoenau says the first year of the study was used for preparation work like selecting zones and watershed basins and getting baseline assessments of nutrient levels in the soil, so it’s too early to have real results from the first manure application at the start of May.