Topdressing Grass Hay

I go back and forth on whether this is a good thing to do.  This year we finished first cutting early and I topdressed the first area with 65-0-0-24S.  Just made that hay this week, 332 bales of beautiful hay but at what cost?  the fertilizer was 860$ for the 18 odd ac, fair number of tractor hours to cut, ted once, rake, flip, and bale.  sells for 6/bale so gross revenue of about 2K.

 

Now if i did not topdress, I would still need to trim it with the bushhog for weed control for horse nettle and milkweed control if nothing else so there is going to be some tractor hours no matter what the choice.  So here I am again debating on topdressing for third cutting.  I read Trotwoods post the other day and automatically fell in line and scheduled the fertilizer for tomorrow morning.

 

But I continue to ponder Is it worth it?  I am an agronomist by training but spent most of my studies on soils, not crops.  I can tell you all sorts of things about how soils handle the nutrients, not so much with the plants. My assumption (meaning, I believe, but do not know) is that it is better to keep plants healthily growing to maintain vigor, suppress weed pressure etc so that even with marginal yields it makes overall economic sense to topdress.  two years ago, I topdressed second cutting and never harvested a bale afterwards.  however, it started to rain in oct and by Nov, I had a bumper crop, just no weather to harvest.

 

Just curious, what do others think, do you topdress with no better than a 50-50 chance of making any profit on the second and/or third cutting?

Topdressing Grass Hay