Pea fertility research results support improved yield

Research funded by Saskatchewan Pulse Growers (SPG) explored the effect fertilizer use had on protein and yield of field pea. The results have shown that specific combinations of nitrogen, phosphorus, and sulfur fertilizer applied at specific rates when seeding yellow field peas, can significantly impact crop yield.

Trials conducted by Chris Holzapfel, Research Manager at Indian Head Agricultural Research Foundation (IHARF) determined that:

- Overall pea yield benefited from fertilizer application. Yield was maximized both agronomically and economically at 35-45 pounds (lb) of phosphorus per acre (P2o5/ac), providing a 13 per cent yield increase over the treatment with 0 lb P2o5/ac.

- Higher rates of phosphorus may provide a benefit where growers are aiming to build soil phosphorus over the long-term or where yields greater than 50 bushels per acre are targeted.

- Application of sulfur did not impact pea yield or protein in this project. Where crops have exhibited sulfur deficiency or soils are low in sulfur, a small amount of sulfur may provide a yield or protein benefit.

- Application of nitrogen above the nitrogen provided in phosphorus and/or sulfur fertilizers did not improve yield or protein, regardless of the timing and placement. Extra nitrogen may provide a benefit where the soil nitrogen is extremely low and phosphorus or sulfur is not being applied, or where nodulation has failed.

This supports established research and strategies to increase pea yield and protein content, which is another piece of information that can allow growers to make decisions on their farm to help improve their overall pea production and also capture potential protein premiums.

“Producers are always looking at the newest ways to maximize their crop yield and reduce their costs through more efficient usage and practices,” says Holzapfel.

“These trials helped us pinpoint what fertilizers at what rates would help producers boost their field pea yields. The rates that not only maximized yield from an agronomic perspective, but also economically. While protein content may see improvement from applications of phosphorus fertilizer, the trial results were not conclusive.”

“Nutrient management in pulses is important for maximizing yields but also keeping plants healthy which can help the crop withstand pest and environmental pressures,” says Sherrilyn Phelps, Director of Research and Development at SPG. “At SPG one of our strategic goals is increasing the provincial average yield of peas to 43 bushels per acre by 2025, and fertility management is one aspect that can help attain that goal for growers.”

This work was funded by Saskatchewan Pulse Growers. AGRI-ARM sites received base funding through the Canadian Agricultural Partnership bi-lateral agreement between the Federal Government and Saskatchewan Ministry of Agriculture.

Collaborating sites include IHARF, Irrigation Crop Diversification Corporation, Wheatland Conservation

Area, Northeast Agriculture Research Foundation, and Western Applied Research Corporation.