"Horse Manure" and its calorific values.

michael johnson · April 6, 2007

I was lucky enough to finally find a supplier of good horse manure- as its very scarce round here these days-owing to some crackpot government legistation on manures.

However- when I went to collect it, I was directed to a large heap in one corner of the stables yard-well rotted 2 year old stuff, almost black with nice short straw texture, but as I was digging it I realised that it was stone cold- not a bit of heat in it.

And I often wondered -if we all make a big mistake over this, as good horse manure is generally considered mild in strength and would not burn the roots of anything if used semi-fresh, and it always retains its heat value as it breaks down.

Years ago in the fifties-they used to construct hot beds for tomatoes and cucumbers made up of large lots of horse or cow manure in the base followed by five or six inches of good loam soil on top,the beds when watered well used to hot up to a fairly high temprature and they used to stick a thermometer in the bed and watch it on a daily basis, and when the temp started to come back down again and reached about 80 degrees F, then they used to plant all their plants in it with great speed and gusto, all the plants used to grow like crazy with huge crops of the most tasty tomatoes and cucumbers you could ever imagine.

I wonder if anyone has ever done a scientific study on manures- to determine the facts if or not it loses its Nitrogen and other values as it ages to a much more reduced value once the heat has gone out of it.

Is the old black well rotted horse or cow manure really as good as it is supposed to be, even though it looks good-smells good etc, is it nearly worthless in food value to the plants, compared with the food value of the fresh stuff and of course the beneficial heat.

Does the nitogen and other elements go down or up as it rots into a more concentrated form the NPK value might well be far lower in the well rotted stuff than in the fresh.

I wonder-I wonder-

dice · April 6, 2007

The ammoniacal nitrogen in fresh manure evaporates
(IIRC fresh horse manure is something like 8-1-1 NPK
ratio, while composted horse manure is about 1-1-1,
and it gets there pretty fast). I don't expect that
potassium gets used by composting (although
some of it may leach out of an open pile from
rain washing through it), and the phosphorus
in it definitely isn't going anywhere.

michael johnson · April 7, 2007

Yes- its very difficult to sort out the best time to use it, obviously ammonia is not ideal for tomatoes in any form- as its a bit too strong for them.

I prefer grass fed horses to those fed on other feeds, mixed with a nice sweet meadow hay for bedding.

apart from the plant food values- manures make a very good soil conditioning agent- if not overdone.

In holland they had a big problem with manures a few years ago- they used too much of it on a regular basis- thousands of tons of it spread over the land, until someone noticed that the heavy metals elements were slowly climbing upwards and apparently it was not good in any form.

April 6, 2007	#1
michael johnson Tomatovillian™ Join Date: Jan 2006 Location: UK. Posts: 960	"Horse Manure" and its calorific values. I was lucky enough to finally find a supplier of good horse manure- as its very scarce round here these days-owing to some crackpot government legistation on manures. However- when I went to collect it, I was directed to a large heap in one corner of the stables yard-well rotted 2 year old stuff, almost black with nice short straw texture, but as I was digging it I realised that it was stone cold- not a bit of heat in it. And I often wondered -if we all make a big mistake over this, as good horse manure is generally considered mild in strength and would not burn the roots of anything if used semi-fresh, and it always retains its heat value as it breaks down. Years ago in the fifties-they used to construct hot beds for tomatoes and cucumbers made up of large lots of horse or cow manure in the base followed by five or six inches of good loam soil on top,the beds when watered well used to hot up to a fairly high temprature and they used to stick a thermometer in the bed and watch it on a daily basis, and when the temp started to come back down again and reached about 80 degrees F, then they used to plant all their plants in it with great speed and gusto, all the plants used to grow like crazy with huge crops of the most tasty tomatoes and cucumbers you could ever imagine. I wonder if anyone has ever done a scientific study on manures- to determine the facts if or not it loses its Nitrogen and other values as it ages to a much more reduced value once the heat has gone out of it. Is the old black well rotted horse or cow manure really as good as it is supposed to be, even though it looks good-smells good etc, is it nearly worthless in food value to the plants, compared with the food value of the fresh stuff and of course the beneficial heat. Does the nitogen and other elements go down or up as it rots into a more concentrated form the NPK value might well be far lower in the well rotted stuff than in the fresh. I wonder-I wonder- Last edited by michael johnson; April 6, 2007 at 09:42 AM.

April 6, 2007	#2
dice Tomatovillian™ Join Date: Jan 2007 Location: PNW Posts: 4,743	The ammoniacal nitrogen in fresh manure evaporates (IIRC fresh horse manure is something like 8-1-1 NPK ratio, while composted horse manure is about 1-1-1, and it gets there pretty fast). I don't expect that potassium gets used by composting (although some of it may leach out of an open pile from rain washing through it), and the phosphorus in it definitely isn't going anywhere. __________________ -- alias

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April 7, 2007	#3
michael johnson Tomatovillian™ Join Date: Jan 2006 Location: UK. Posts: 960	Yes- its very difficult to sort out the best time to use it, obviously ammonia is not ideal for tomatoes in any form- as its a bit too strong for them. I prefer grass fed horses to those fed on other feeds, mixed with a nice sweet meadow hay for bedding. apart from the plant food values- manures make a very good soil conditioning agent- if not overdone. In holland they had a big problem with manures a few years ago- they used too much of it on a regular basis- thousands of tons of it spread over the land, until someone noticed that the heavy metals elements were slowly climbing upwards and apparently it was not good in any form.