Pulse School: How much residual N is too much?

(Kara Oosterhuis/RealAgriculture)

Drought or even just dry conditions can significantly impact a crop’s ability to make use of applied fertilizer. What happens when there’s plenty of nitrogen left in the soil ahead of rotating to pulses?

That’s the question being asked in a trial happening across three Saskatchewan sites through the Agri-ARM research network.

Mike Brown, agronomy manager with Saskatchewan Pulse Growers, says the trial includes 12 treatments: both small red and large green lentils were seeded in plots where three different rates of nitrogen fertilizer had been applied last fall, and are either inoculated or not inoculated.

Brown says the trial is being replicated at Swift Current, Indian Head and near Scott, Sask., and they are seeing some differences between sites based on rainfall.

The trials will be taken to yield, but so far the plots look comparable with some colour differences noted in the uninoculated plots.

Brown says the question of carry-over nitrogen has been a popular discussion topic throughout the winter season, as residual N could mean pulse crops put up too much vegetation, or might mature later, and those outcomes would require different variety selection.

Wake up with RealAgriculture

Subscribe to our daily newsletters to keep you up-to-date with our latest coverage every morning.

Wake up with RealAgriculture