Research explores ways to hone fertilizer calculations

Thursday, May 8, 2014

by MATT MCINTOSH

Nitrogen and phosphorus are essential for crop growth, but our understanding of nutrient uptake and runoff could be imporved, says Keith Reid, a Guelph-based soil scientist and agronomist working with Agriculture and Agri-Food Canada.

Reid and other collaborators are compiling and analyzing the research of a dozen scientists from across Canada under two new projects called Project-P, which focuses on phosphorus, and Project-N, which looks at nitrogen.

The goal, he says, is to strengthen the information available to producers so they are better positioned to optimize their use of critical crop nutrients while minimizing their impact on the environment.

“It’s about pulling together, packaging, and making available research information that producers can use,” says Reid. “The tools we currently have to measure runoff and nitrogen uptake leave out some important things.”

For Project-P, for instance, Reid says current phosphorus indexes – which rank the relative risk of surface water contamination resulting from phosphorus application on crop land – could do a better job of taking into account the effect of tile drains in determining what parts of a field are at a higher risk for phosphorus runoff. Consequently, the impact of tile will be included in Project-P.

Once it is possible to make predictions on phosphorus runoff based on the information compiled in the project, Reid says they will be cross-referencing their predictions with data detailing the actual levels of phosphorus in water near their prediction site.

“We want to see if our predictions match up with how much phosphorus actually makes it to the water,” he says. “It will tell us if we need to alter our formula.”

While Project-P looks to measure the risk of phosphorus loss, Reid says Project-N involves the development of a “decision support system” that will help producers better predict the nitrogen needs of their crops, and consequently, the best nitrogen-application rate for their fields. Reid says there is a lot of good information already available to producers, but stresses that some areas – such as information relating to the weather’s effect on nitrogen uptake – will be further developed.

Initially, he says, they are focusing on the nitrogen needs of corn. Expanding their support system to include canola, potatoes, and spring wheat is a longer-term goal.

Reid says both Project-P and Project-N will wrap up by 2016, and he hopes that predictive tools for phosphorus runoff and nitrogen uptake will be available around that time. Reid notes the intent is to use the results of Project-P and Project-N in conjunction with the information already available through provincial governments.

“We want to generate information that can be moved to farmers through our provincial partners,” he says. “We don’t want to produce competing information.”

Reid is a regular contributor to Better Farming magazine. BF