Originally Posted by Smallaxe
Does this mean that it makes sense to apply N in the winter, because most of it may stabilize in the frozen turf??? But we don't want a fresh supply of N as soon as the plants break dormancy in the Spring...
That is one of the issues of cool-season grasses having the ability to put down roots w/out the waste of topgrowth energy... anhydrous ammonia is fine for corn, but not for turf...
Hang on there, Tex!! You're missing the boat on the N issue. Do we want a supply of N as soon as plants break dormancy? YES!!!
You say you're railing against "conventional wisdom," but you're using such "wisdom" in thinking that N is necessarily antagonistic to root growth. Nothing could be further from the truth! N is needed by all plant tissues. High N applications don't even harm root growth (so long as sufficient moisture is present). I think people get this idea from N driving top growth more than it would drive root growth. But, applying more N won't slow roots down -- they'll grow at the same pace. It's just that you'll haveto mow more while its happening.
The tilth that you keep talking about is more of a soil physical property thing and is important in allowing aeration and water infiltration and drainage in the soil, which promote the biological processes of the N cycle. Humus has a lot of CE sites and holds water well, but is mostly brrken down (definition of humus) and doesn't contribute much chemical fertility.
Again, having available N in the soil at dormancy break will not "burn out" roots or carbohydrate reserves. Remember the 16 essential plant nutrients. N is one of them. N is a critical component of the chlorophyll molecule. If we don't have much of it in the spring, we can't produce the carbohydrates needed to replace those lost due to winter respiration.
If you trying to best set up a turfgrass plant for success as it comes out of dormancy, why would you withhold a nutrient it needs for survival?