[Arid_gardener] Re: Horse Manure as Fertilizer.

[Olin Miller]

Animal manures are beneficial as organic soil conditioners but not very good
as fertilizer.  A 20 pound bag of ammonium sulfate (21-0-0) contains 4.2
pounds of nitrogen.  The NPK of horse manure, according to most dot edu
websites, is 0.70 - 0.30 - 0.60, or 30 times as many pounds of horse manure
are needed to get the same amount of nitrogen.  The nitrogen content varies
considerably depending on the horses' diet - up to 2.5 % according to some
websites.

There is a process called "sheet composting' where the fresh manure is
spread on the soil and left to dry and decompose except decomposition is
very slow in our climate and alkaline soil.  If is rototilled into the soil
it should be left to fallow for a season so as not to rob the crop of
nitrogen which is needed to compost the manure.

But there are a few other considerations which, to me, are reasons not to
use horse manure in a vegetable garden but it might be okay in flower beds.
I also realize that many people do not see these as problems.

The first is the possibility of introducing pathogens into the garden soil
if the animal is not wormed on a regular schedule.  Typically horses are
wormed at six month intervals thus preventing worms but the vermicide also
passes through the horse's digestive system and into the soil thus probably
introducing residual vermicides into the soil and potentially killing off
beneficial soil organisms.  There is also a systemic worming method where
the horse receives a daily small dosage of a vermicide.

Another reason is that of introducing weeds into the garden, primarily
invasive Bermudagrass.  Show horses and race horses probably receive pure
hay in the form of pellets , Bromegrass, or Timothy and it would not be a
problem.  But many pleasure horses feed on locally grown grass hay which is
high in giant Bermudagrass and, in flood irrigated fields, other strange
weeds that come with the high country runoff irrigation water.  Unlike
cattle which have a pretty elaborate digestive system with three stomachs
and a rumen, a horse has a straight through digestive  system which passes a
lot of seeds.  Most composting systems do not get hot enough to destroy the
seeds that can become a nuisance in a garden.

Olin Miller, Master Gardener Volunteer
U of A Cooperative Extension, Maricopa County AZ
============================================

----- Original Message ----- From: <madjoaz at cox.net>
Sent: Thursday, November 29, 2007 10:44 AM
> Joaquin Neves,  85042
> I live in Phoenix at South Mountain Village and own two horses. They
> produce a substantial amount of manure which I have been stockpiling and
> then removing to a landfill. I want to do something more eco-friendly with
> this manure and was recently advised that horse manure is a good organic
> fertilizer. I have resaerched this matter and have come to realize that it
> is as i was told. Some of the sources I found reccommend composting first
> and others state it can be used in as is state in certain circumstances.
> My problem is I don't have a resource locally that I can turn the manure
> over to
> either free or at a minimal charge depending on the method of turn over.
> Please advise if you can.
> Thank you for your consideration.
> Joaquin Neves