Soil nutrient levels this fall will be all over the map if early soil tests are any indication, says an agronomist with Enviro-Test Laboratories.
“We’re seeing soil nitrogen levels from very low to very high, but that does make some sense,” Brandon Green said.
“In Manitoba, rainfall was generally pretty good this summer, so crops used a lot of nitrogen and some of it might have been leached.”
For years, however, Manitoba growers have been applying good levels of nitrogen fertilizer, which means the soil kicks out more nitrogen through mineralization in a wet year.
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Alberta’s Peace River region also saw decent rainfall this summer.
Nitrogen application there last fall and spring wasn’t high, but a lot of the region had drought the last couple of years, so residual nitrogen levels were high at the start of the growing season.
Southern and east-central Alberta and most of Saskatchewan had little rain this summer and overall yields are down significantly.
But rain was so variable in some areas that fields only a few kilometres apart had significantly different yields.
A lot of producers cut back on nitrogen fertilizer last spring because of high nitrogen prices and low moisture levels.
“Plus, the crop takes up a lot of its nitrogen requirement early in the growing season – before it got really dry.”
As well, high grain protein levels indicate the crop continued to take up nitrogen late in its growth cycle.
So how much nitrogen will be left in the soil?
“You just can’t predict it,” Green said.
“When you have average rainfall, and I’m not sure when that ever happens, you have a shot at it.
“In wet and dry years with variable soil nitrogen levels to start the year, you don’t have a chance, you have to soil test.”
