Project: MLMMI 07-02-04
To showcase a more prescriptive way of applying and managing manure nutrients. This objective will be achieved by creating 2-4 distinct management zones within each field which will each receive their own nutrient application rate based on the soil test status. Applying manure nutrients based on site-specific nutrient requirements will ensure that nutrients are utilized to their fullest potential.
KEYWORDS: Nutrient Management, Precision Agriculture, Environmental Benefits, soil variability
Agra-Gold Consulting &
Farmer's Edge Precision Consulting
Funding Partners: who have contributed to MLMMI in support of this project:
MRAC - $23,625;
Manitoba Pork Council - $23,625
Performer funding obtained from:
Amount Funded: $47,250.00
Performer Funded: $7,500.00
Total Cost: $54,750.00
First progress report due July 30, 2008.
First progress report received July 28, 2008.
Second progress report due January 30, 2009.
Second progress report received January 28, 2009.
Third progress report due July 30, 2009.
Third progress report received July 30, 2009.
Final report due January 30, 2010.
Extension until March 31, 2010 granted.
Final report received March 2010.
The demonstration project reported herein was designed to test whether or not current variable rate (VR) commercial fertilizer techniques can be adapted to manure applications. The potential agronomic/economic benefit would be increased yields in more productive areas of the field by applying more nutrients to these areas. The environmental benefit would be a reduced application rate in less productive areas which would decrease the residual amounts of nutrients in these areas and therefore decrease the environmental risk of losing nutrients to waters.
The project demonstrated that VR commercial fertilizer techniques can be adapted to manure applications. Although we received generally positive feedback from producers on the methodology and agronomic benefits of this management style, producers had difficulty in justifying the cost of this increased management. In over the applications, producers perceived an environmental benefit from the VR approach versus the traditional one rate approach. Overall VR manure did not achieve its fullest potential (as seen from commercial fertilizer variable rate successes) because the technology used by commercial drag line applicators today cannot efficiently and practically carry out this type of application. The 3 major limitations to wide-scale adoption of this technology with drag-line applicators are:
- Adjusting the rate of application is a manual process of increasing or decreasing speed, and accuracy is often compromised.
- The precise nutrient concentration is unknown until after the application when a manure sample can be sent to a lab for analysis. Without having an on-the-go sensor to accurately determine nutrient concentration, nutrient planners have to rely on historical manure analysis for rate determination.
- Manure has a fixed nitrogen to phosphorus rate (the nitrogen and phosphorus rates cannot be independently varied) which can lead or an over or under application of the nutrient you are not using to set the application rate. In commercial VR fertilizer applications, the nitrogen and phosphorus are applied independently of each other to match the crop requirements. Though increases in technology and management can help to overcome these hindrances, it is our opinion that variable rate manure applications are not commercially feasible today.
Producers can still realize the benefits of precision farming techniques today on their manured fields by applying a base rate of manure using traditional methods and then applying a variable rate starter blend of commercial fertilizer at the time of seeding. This would allow the agronomist time to receive the manure analysis back from the lab and give a more accurate as-applied application report before the commercial fertilizer prescription map is developed.