There has been a renewed commitment between the US and Canada to reduce nitrate and phosphorous loading into the Great Lakes River Basin and maintain soil nutrients levels through the Great Lakes Water Quality Agreement. Conservation Authorities (CAs) have been set up in Ontario to act as the primary mover in watershed management programs. They’ve coordinated with both provincial and federal authorities for non-point source pollution control in priority watersheds. Two areas that needed prioritization for nutrient reduction were Lake Simcoe and Grand River: the latter being the largest watershed in southern Ontario covering 6,800 square kilometres.
4R Nutrient Stewardship Plan
One of the key tools in helping manage the nitrogen and phosphorus levels in the Grand River watershed is the 4R Nutrient Stewardship Plan. It emphasizes the importance of utilizing the Right Source at the Right Rate, the Right Place, and the Right Time. It entails efficient use of phosphorus and nitrogen to minimize runoff and still maintain optimum soil nutrients levels for crops. With the help of all agencies from the local to the federal levels, the aim is to ensure a sustainable supply of water for communities and ecosystems, reduce potential flood damages, and improve water quality (which includes lowering concentrations of nitrate and phosphate in the river system) and the watershed’s resilience to climate change.
Farmers can participate in this program by tapping the services of professional advisers such as certified crop advisers or professional agrologists. They can help with development of a 4R Nutrient Management plan tailored specifically for their crop requirements.
Sustainability Goals and Performance Indicators
One of the challenges of the 4R program is the sustainability of agriculture to accommodate growing demands without compromising natural resources. There are also the added dimensions of social goals, environmental impact, and economic prosperity that need to be achieved. One aspect of determining progress is the setting of performance indicators to ensure that all the goals are met. After the sustainability goals are established, performance indicators are needed that measure things like soil quality in terms of soil organic matter, compaction, and productivity. Water quality can also be assessed for nutrient and sediment load that is in the runoff. Economic parameters are based mostly on profitability and return on investment. Since the aim of 4R is to better manage soil nutrients used in farms, production information from farm-to-farm and even within individual fields needs to be documented. If certain information such as nutrient content in manure cannot be determined by the farmer, then they can always check with the Provincial Agricultural Registry or through advisers for the average rates in their area. This is all in an effort to come up with complete and accurate data for better analysis.
Spatial Location
Information like spatial location and size of the field or management zone is also vital. This includes data on slopes, water body proximity, manure storage, tile drainage, or other distinguishing features. Tools such as Google Maps, GPS, aerial photos, and agri-maps are useful in helping with assessment. Landscape topography and soil drainage characteristics can be accessed using a mapping tool called Ag Maps provided by the Ontario Ministry of Agriculture and Rural Affairs (OMAFRA). The organization assists in identifying environmentally sensitive areas to ensure compliance in the event of buffers and setbacks. Crop types and yield information are necessary to forecast future yield quantity and quality.
Realistic Yield Targets
In order to manage crops effectively, a realistic yield target is needed when submitting soil samples to a soil laboratory for an accurate recommendation for the proper applications of N, P2O5, K2O, and S to achieve the targeted yield and avoid over application of nutrients. Aside from soil analysis, manure analysis may also contribute to a spike in nutrient load. This can be compared to previous measurements to track the amount of soil nutrients that may be needed for the current season’s crops. It is important to work with an advisor to find the ideal amount of nutrient application and schedule for the upcoming season.
Accounting of Phosphorus and Nitrogen Sources
The changes needed for 4R implementation are incremental over time to identify any differences in crop output and water quality. A complete accounting of all sources of phosphorus is needed and external application should be targeted and optimally timed. Surface applications should be made in later spring or early summer to allow for P to bind with the soil. Nitrogen sources need to be soluble for enhanced efficiency and compounding N sources from manure and irrigation water should be taken into consideration.
Post-harvest Nutrient Balance
The best way to assess performance of a farm in meeting 4R standards is by conducting a post-harvest nutrient balance. This would help in fine-tuning any changes needed for the next crop season. Nutrient balancing is a metric of environmental performance, which, on top of economic and social priorities, is what makes 4R different from typical nutrient management planning.
Thomas Nutrient Solutions is made up of long-time Niagara residents with years of experience managing Niagara biosolids. We have worked with some of the largest industrial and resource operations in the world, playing an integral role in the handling and removal of environmentally sensitive by-products of their operations.
If you are a municipality in Ontario and in need of a biosolids management solution, please feel free to contact us at 1 (877) 479-1388.
Source:
Fertilizer Canada