Any of a number of factors can cause a pulse crop to become nitrogen deficient, particularly issues with inoculant. Using the wrong Rhizobium species, applying inadequate rates or storing bacteria improperly can decrease the likelihood of proper root nodulation. Less controllable factors, like extreme plant stress or inoculant/soil desiccation can also have a huge impact. Thus, even our nitrogen-fixing friends can become nitrogen deficient.
Besides being able to assess root nodulation, those scouting pulses should be ready to identify symptoms of nitrogen deficiency, among other nutrient issues.
In this Pulse School, Shannon Friesen, regional crops specialist with the Saskatchewan Ministry of Agriculture, speaks briefly about timing when rolling pulses (keep that in mind for next year!), and discusses the key characteristics to look for nutrient deficient pulse crops. Friesen also discusses how to determine whether or not saturated soils are playing a role in a crop’s health, judging by whether or not they have “wet feet.”