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Utah

My PH came back as 7.5 and OM 3.2 My question is if I add copious amounts of manure will it drop the ph down to a reasonable level or will I need to amend the soil as well. My lot is aprx 35X95. How much manure would be enough. I am hopeing to get 10 pickup loads. THoughts?

12/20/2007 11:55:05 AM

Danville, CA (petman2@yahoo.com)

My soil is 7.7 and I added 25 yards of partially composted manure last year and 13 more this year with little effect on pH. Adding that much manure however will likely rob your plants of Nitrogen as it breaks down unless it is highly composted already. I am going to use sulfur as an amendment VERY soon so that it can get to work over the winter, however the amount I need to get to 7 is quite high and I don't want to make it toxic to the plants so I am going to go a reasonably heavy dose of sulfur.

12/20/2007 3:16:22 PM

Picton,ON (j.vincent@xplornet.ca)

I would use 75 lbs of 90% sulfur/ 1000 ft2 in the spring. This should move your PH from 7.5 down to 7. There is very little danger of toxicity, unless you have excessive sulfur levels already. Add the manure as well as long as it is well composted. If not, go easy. I dissagree with Petman on Robbing the plants of N. This would only be the case if the manure was mostly sawdust or a lot of undecomposed hay. It is more likely that the oposite is true, you may provide too much Nitrogen by adding manure in the spring. Seek out fully decomposed compost or manure.

Also, check out my diary on sulfur use

John

12/20/2007 10:34:57 PM

Sheridan . NY

Your ph yes can be brought down by sulfer-- but also by adding more organic matter thats low in ph and since your OM is 3.2 --OM need to come up also - I would suggest buying a ph kit and seeing of you can find some compost that is low in ph 6.0 to 6.5 range--most old 5-6 year old --hay piles- leaves- wood chips will be some were around that --Think of you soil as some thing you going to mix up and you going to eat-to much salt in soup--- add twice the water and it edible---craig

12/21/2007 8:17:20 AM

Windsor, Ontario, Canada

John, 75 lbs should bring it down from 7.5 to 7.0. Hmmmm, I was told that 100 lbs per 100 gets you 0.3. I went a little on the light side, than I thought I needed though, so I should be fine.

I was at 7.4 and I put down 100 lbs for 1500 square feet. Thats more like 67 lbs per 1000. So maybe I can expect 0.4 change? That would be good, bring me down to 7.0.

Does that sound right?

12/21/2007 10:46:27 AM

Danville, CA (petman2@yahoo.com)

I don't want to hijack but also don't want to post incorrect information. My comment as to the nitrogen was based on reading the web and in part on other comments here. My understanding is that nitrogen is used by the bacteria that breakdown the manure so there could be a tie-up upon adding the manure followed by a release when it is broken down, again depending on how well it is composted.

This article provided good insights as to the amounts and cycle of nitrogen
http://www.bigpumpkins.com/ViewArticle.asp?id=62

That said, I keep adding and adding and my pH doesn't seem to drop. The texture is getting better and better though. Glad to here the likelihood of toxicity is low. I am not a soil expert by any stretch and given that John is clearly a better grower, I would go with his advice. I would like to discuss this more in another thread though...

12/21/2007 11:33:42 AM

Picton,ON (j.vincent@xplornet.ca)

Peteman

You are correct about the bacterial breakdown. What we are talking about here is Carbon: Nitrogen ratio. An example of manure that is high in carbon would be horse, bedding pack manure and where the bedding material was ground wood pellets or sawdust. This manure would low in the Feces/Urine component. This would be a good candidate to ‘suck up’ the available N to break down the carbon.

The other extreme would be a liquid poultry or hog manure that is very low in bedding material in this case there would be no tie up at all, rater a surplus of N.

My point here is that a broad statement like “Adding that much manure however will likely rob your plants of Nitrogen as it breaks down” is an incorrect statement. It really depends on a lot of factors. The fact is that I don’t think any one here would be adding a non-composted manure such as described in my first scenario.

12/22/2007 10:48:41 AM

Picton,ON (j.vincent@xplornet.ca)

I have done a lot of research on the subject of lowering PH with sulfur. The problem is that it is accepted that it is not economic to lower PH from a base 8 or 7.5 so there is almost no reliable data. As far as the correct amount, what works in my soil is like different than will work in your soil. Some of the principles to consider is that PH is exponential. That means that 7.1 is 10 X more alkaline than PH7. 7.2 is 100 X more Alkaline than PH7 and so on. So theoretically it takes more sulfur to lower from 8 to 7.5, than it would from 7.5 to 7. The other factor is the buffering capacity of the soil. Soils high in free calcium carbonate such as mine take a lot of acid to bring down the PH. I was worried about putting too much on last spring, but we went ahead with the 65-75 lbs/ 1000 and we grew a new patch best weight. I can hardly wait until spring to take the next soil test.

I have added a lot of organic material over the last few years and in my opinion, in high PH, high calcium carbonate lime stone based soils, you won’t lower the PH much with the addition of OM. On the other hand, low calcium carbonate, granite based sands that are notoriously low in PH are easily buffered and you will find that you will need to add more lime to keep the PH up, when you are adding a lot of manure or compost. Obviously there is soil type on the middle, the ‘utopian’ loams that are perfect in texture, PH 6.8 and easily manipulated with the addition of amendments. The PH of these soils generally will be lowered with the addition of OM. My point here is that all soils are different in how they will react to amendments.

12/22/2007 10:58:13 AM

Mastic Beach, New York

how about peat moss? add's o.m and should lower ph

12/22/2007 5:40:38 PM