|
Chesley, Ontario | Alfalfa leaves a lot behind in the roots, plus if it is down for a few years, you are burning out organic matter less frequently with tillage. Are you plowing down bare stubble, or do you have some regrowth that is plowed in when you rotate to potatoes? 1% is pretty low, so almost any addition of organic matter will help to increase the percentage. On the other hand, if you have switched to shallower tillage, you may be increasing the OM percentage in the top 6", but not increasing the total amount since you haven't mixed it through as deep a layer.
There is a lot we don't know about organic matter dynamics, particularly when it comes to removing all the biomass. I worry more about annual cropping systems (e.g. corn silage), since we aren't accumulating a large root mass to make up for the top growth we are removing. | |
|