Urine adverse effects

I got some fruit trees at my local Home Depot and Lowe's. I intend to fertilize them using urine. These trees are:

-Simmonds avocado
-Powder Blue blueberry
-Glenn mango
-Thai guava
-Magnolia fig
-Natchez blackberry
-Kiwi (actimidia arguta)
-Triumph muscadine grape
-carambola
-Centennial Kumquat

I am fairly sure that the avocado, the mango, the kiwi, the muscadine grape, the carambola and the Kumquat will respond favorably to urine application, but I don't know about the others. 

I think most all plants will be fine with urine as a fertilizer.  The usual precautions of being careful to dilute and avoid over-salting an area would seem applicable.

I've used urine for fertilizing many of our plants and had no trouble with it.  I tend to be cautious with some specific plants like the blueberries.  They do not tolerate much in the way of calcium.

Also, the trees on your list probably won't need much in the way of fertilizer if they are in a healthy soil.  The bushes and vines will appreciate more fertility, but using high levels of fertilizer is a fast way to encourage disease and insect damage, IMO.

My suggestion would be to use most of your day-to-day urine as a way to grow more chop and drop mulching plants and nutrient accumulators.  Then use THAT material on around your trees to provide a nice modest level of fertilizer over the long haul.

Under certain soil conditions, urine/urea will break down into ammonia - as it does with a diaper pail. Ammonia is highly alkaline, and it can cause issues for acid-loving plants like blueberry. I would not be surprised to see the plants display nutrient deficiencies if that happens, but it depends on your soil type, how wet it is, etc.

What K.B. & Jonathan said......... I compost everything before it gets used as a soil amendment.

Good to bring up.  I have been using a 20:1 urine solution for mustard and spinich family greens in the digging garden with no ill effect and good leafy growth and color. 

I'd suggest that soluble nitrogen is not a replacement for stepping up organic matter cycling.  The flush of nitrogen stimulates bacterial decomposition of existing soil organic matter.  Thus using a soluble nitrogen source works better when there is organic matter to burn, and you are indeed burning organic matter faster.  Therefor, I don't see a substantial 'biological difference' between using urine, and using chemical urea (a cheap nitrogen source), or some ammonium formulation for that matter.  And so all the same considerations apply.  In general, using soluble nitrogen on tree crops is a short term and hopefully temporary fix.

I suspect the most efficient use of urine would be to add it to a high carbon organic matter where it is rapidly bound up in bacterial bodies, and thus enters to soil food web in a more stable form (essentially what D. Bennett said...)

I think the ammonia vs. ammonium balance as a breakdown product of ureic acids is both about redox state and pH, with high pH or low redox making more ammonia.

Your right, Paul, that too much nitrogen (from any concentrated source) will generally lower soil organic matter levels. Nitrogen feeds the microbes that breakdown carbon compounds. But if a soil is already low in organic matter and nitrogen, applying nitrogen will increase biomass and organic matter levels.

I apply the stuff directly to the lawn.  Besides the convenience, I do get enhanced growth in the areas served, but I'm not growing Jack Beanstalks.  Frequent application in the same area shows adverse effects-a dead spot will develop.  I now apply the product to different areas whenever possible. 

I've applied it directly to compost, but if customers knew about this, I would expect sales to suffer.