Eric, I live in Central Texas, so I have to relate the use of urea to those environmental conditions. We only use urea when the weather is cool, 60-75 degrees F. Other wise we loose nitrogen unless rain occurs very soon. It doesn't matter whether you use urea(82% N) or ammonium nitrate (33% N) as both are obvious nitrogen sources. What does matter is the cost per unit. If the weather is cool use the most economical source. The cost of urea per ton will be higher than nitrate but you will use less pounds per acre to obtain the same application rate. I can explain more if needed. On legume pastures, which you said you didn't have, I hesitate to use urea because the incidence of bloat is greater in central Texas maybe because producers do not apply the same rate of actual nitrogen when the two sources are compared, so folks may not be comparing apples to apples.
Question: What are the adverse
> effects of fertilizing pastures
> with a fertilizer mix of 29-12-12,
> can there be any adverse reactions
> to the higher nitrogen in lush
> grass to cows/calves? Will there
> be any other nutritional needs
> that occur due to a highly rich
> grazing condition? note: Legumes
> are NOT present in pasture.