The effect of feeding round bales in the pasture

Much of the valley pasture looks like this, with very little growth.

This is what the pasture looks like where a round bale has been fed to the cows in the previous fall. The hay provides clover and orchard grass seed and the cows provide manure for fertilizer. Timing is important - if it is too wet the cows will make a mud hole. Also, spacing the bales far enough apart is important or the concentration of urine will kill the grass.
The valley pasture was given a good rest this year. Today the cows came back in as the weather is turning cold.

LlewLlaw says this patch is mine while Rosie goes after a vole.
That's about the most succulent clover I've ever seen.
Here you can see the transition zone from where a round bale was placed.