By Bruce Kelly, Farm & Food Care Ontario
At a farm near Woodstock Ontario, the Oxford County Soil and Crop Improvement Association is undertaking an innovative project using variable nitrogen application rates on corn.
At this point in the growing season, very few fields have even plant growth. Differences in soil type and precipitation can leave corn fields looking an uneven green or pale in colour and in need of nitrogen (N) to promote proper growth. But it can be difficult for farmers to determine how much to apply.
A project receiving funding from the Water Resource Adaptation Management Initiative (WRAMI) uses Green Seeker technology for zone management of nitrogen application. Rather than apply fertilizer at a uniform rate over an entire field, the system, mounted to the front of a tractor, measures the “greenness” of the corn plant (its chlorophyll content) as it drives along the field. It then directs the nitrogen applicator towed behind the tractor to apply nitrogen only where and at what rate it is needed.
The index also looks at the corn leaves using near infra-red wave lengths. The system is able to provide data about the health of the plant, and evaluate if there is a lack of nutrients. Any plant stresses will be visible to the system before a human observer could notice changes in the plant in the field.
As it is driven through the field, the Green Seeker sensors mounted on the front of the tractor determine the health of the plant and uses an algorithm to determine how much additional nitrogen to apply to the corn. In one pass over the field, it can measure and apply additional fertilizer as required, only in those areas of the field that require additional nitrogen for optimal growth.
The project is testing the economic impact of the variable rate applied nitrogen using the Green Seeker technology as compared to nitrogen strips applied using conventional rates. Cathy Dibble of Oxford Soil and Crop said, “ We hope the Green Seeker system’s benefits will be two-fold. It should help save farmers money in reduced nitrogen costs and be better for the environment.”
Several weeks after the nitrogen was applied, the group arranged a flight over the field using a Precision Hawk unmanned aerial system with an infra-red camera attached below. The purpose of the flight was to observe and compare the results of the applications. Nicole Rabe, Precision Agriculture Specialist with OMAF explained, “We want to use the aerial imagery to see if we can see a difference in the nitrogen treatments from above.”
This is one of 17 projects funded, in part, by the Water Resource Adaptation and Management Initiative (WRAMI), administered by Farm & Food Care. WRAMI is funded by Agriculture and Agri-food Canada (AAFC) and Ontario Ministry of Agriculture and Food (OMAF) from the Agricultural Flexibility Fund, as part of Canada’s Economic Action Plan. Information on all WRAMI-funded projects is available at: http://farmfoodcare.org/environment/10-farm-food-care/environment/238-wrami
To see the unmanned aerial system in action and learn more about this WRAMI project, follow the link here: http://www.youtube.com/watch?v=e7R2c2Tx3og