Science-Based Application of Various Forms of Swine Manure to Improve the Environment and Production Sustainability.

Why is this research important?

There is a considerable amount of swine manure produced each year across Canada. Swine manure is rich in complete crop nutrients, including macro- and micro-nutrients. These nutrient values are equivalent to fertilizer nitrogen, phosphorus, and potassium of CAD $419 million.

Swine manure also contains a significant amount of organic carbon, and its addition to soil can improve soil health, help to increase soil carbon sequestration, and enhance crop resilience to climate change.

Meanwhile, fertilizer input accounts for a large proportion of crop production costs. With increases in fertilizer prices, there is greater interest in using manure as a low-cost alternative to chemical fertilizer. 

As well, the pork sector accounts for 10%  of agricultural greenhouse gas (GHG) emissions in Canada. Finally, inappropriate manure application can cause crop yield loss and/or increases in nutrient loss, especially phosphorus, harming water and air quality.  

What will researchers do?

General goal:

• Develop 4R-based (right fertilizer applied in the right amount at the right time in the right place) recommendations and identify the optimum nitrogen and phosphorus rates in soil-cropping systems that employ swine manure.

Specific objectives:

• Determine the fertilizer values of manure nitrogen in the year of application and the following years.

• Determine the fertilizer phosphorus values of swine manure in the year of application and over the long term.

• Assess the interactions between swine manure and chemical fertilizer.

Approaches:

• Qualify and quantify Canada-wide swine manure samples for nutritional values.

• Using soil samples collected from long-term manured or chemically-fertilized farm fields, conduct greenhouse studies to cover a range of rates for various swine manure forms and soil textures.

• Conduct field experiments for validation and calibration under practical farming conditions, using a corn–soybean rotation as it is the typical cropping system in the region.

• Using a systems approach, assess the effects of swine manure application on major components of the ecosystem. This includes evaluating agronomic performance (predominantly grain yield), above ground biomass, and nutrient use efficiency.

  
  

Researchers will monitor changes in soil moisture, temperature and dynamics, as well as temporal patterns (patterns over time) of nutrients like nitrogen, phosphorus and sulphur. They will determine soil organic carbon storage and soil health variables, such as aggregate stability, bulk density, mineral nitrogen and potentially mineralizable nitrogen, soil test phosphorus and potassium. They will also assess water quality impacts through determination of soil nitrogen and phosphorus runoff water losses.

What has been done so far?

• The project studies are currently at their early stages, with no tangible results to date. 

What will be the benefit of this research?

The project results will aid Canadian farmers in making optimal use of both swine manure and chemical fertilizers in the manured cropping systems. The specified 4R recommendation will reduce chemical fertilizer input and better match nitrogen and phosphorus to crop needs for maximum crop production profitability.

The 4R recommendation will enable farmers to avoid over-fertilization and reduce risks of losing nutrients (nitrogen and phosphorus) to the air and water (lakes, rivers), thereby reducing harm to the environment.The project results will also increase the awareness of soil health and sustainability values of swine manure, in addition to its nutritional values. This may encourage more farmers to use local manure and reduce their reliance on chemical fertilizer.

As well, findings from this study can enable agronomists and crop advisors to create science-based decision tools for manure nutrient management with improved use efficiency. Those findings should also assist policymakers in making evidence-based nutrient management guidelines and regulations.

With integrative analyses of the data, scientists can develop swine manure management practices that enable farmers to produce maximum economic crop yield in a manner that sustains soil resources and is also environmentally friendly.

Project status: Currently in progress. Results expected in 2028.

Collaborators:

• Dr. Bahram Daneshfar, Agriculture and Agri-Food Canada (AAFC)