Nope. And nope.

Slightly acidic is ideal for most plants. Is there a specific reason you need to raise the pH? Or, I guess an even better questions is, what do you mean by "slightly acidic"? I would guess that you're talking somewhere between 6.1 and 6.9.

It's actually in the 5.8 5.9 levels, which is probably by more acidic than I need it to be

Adding organic matter of any kind will tend to bring your soil pH closer to neutral, and will also help buffer the acidity (or alkalinity where I am) when the pH is out of the neutral range.

So compost will raise your soil's pH (and lower mine) but not by much. Wood ashes will affect the pH pretty quickly (and will affect it more), but I think the effects are pretty short lived.

Lime (powdered limestone/dolomite) is organic and cheap so what is the problem with using it?

35 years ago the soil pH test here said my soil pH was 5.7 and today, after only adding organic matter, the same planting beds have a soil pH of 7.2. If organic matter did not raise that soil pH then the people at Michigan State University do not know what they are doing. If is common knowledge, among many soil scientists, that organic matter can buffer soil pH but can also raise that pH.

Tilling about 25 to 50 lbs. of lime per 1000 sq. ft. down to 6 or 8 inches should put you into the 6-something range over time.
bpgreen and spiced ham both make good points.

I already heard lime and wood ash and I guess I wanted to know of all other alternatives

"35 years ago the soil pH test here said my soil pH was 5.7 and today, after only adding organic matter, the same planting beds have a soil pH of 7.2. If organic matter did not raise that soil pH then the people at Michigan State University do not know what they are doing. If is common knowledge, among many soil scientists, that organic matter can buffer soil pH but can also raise that pH.
"

Kimmsr,

Something to keep in mind is that 35 years ago you were receiving a great deal of acidity from rain caused by the burning of high sulfur coal in power plants. Now you are not. Organic decomposition including composting is an acidify process. Whether a compost is going to raise or lower pH depends on whether the composted materials contained more or less base than was required to neutralize the acid produced by the decomposition. Put another way; composts are not all created equally, and unless you know that a particular compost is going to raise pH, I would not count on it to do so.

So are you saying that there is no way composting can somehow bind or utilize cations by chemical reaction via the microflora or other means of decomposition?

The soils in this area of the world are normally in the 5.2 to 5.7 pH range, one of the reasons that Blueberries grow so well around here. I know of others in this area of the world that have done the same thing as I did, change the soil pH by adding lots of organic matter.

Again, if you are adding compost that contains enough bases so that the pH of the compost is greater than the soil, it will raise the pH. I see this commonly is fields that receive a lot of manure (which tend to be pretty salty), the pH of the soils can be as high as 8.1. Conversely if the compost has a lower pH than the soil it will lower the pH of the soil. It would follow then that your compost Kimmsr is slightly alkaline like manure and has pushed your pH up to 7.2. As far as the buffering goes there are two things to consider, if you are adding something to the soil that is roughly neutral it will tend to push the soil pH toward neutral as I have said. Also, organic matter has exchange sites (like clay) and will increase the soils cation exchange capacity. Greater cation exchange capacity means greater buffering capacity which means it takes more acid or base to change pH.

So if I need nutrients and an increase in soil pH from 5.0 to 6.5. Would manure from my chickens, ducks and turkeys help? I'm with Takadi on this one, I don't want to go to the local hardware store every 3 to 5 years and purchase 5 tons of lime to spread on my 8 acres that I'm slowly turning to rotational pasture and crop land. Can manure do the trick? For data I run 4 to 500 broilers, 100 turkeys and 100 layers. This equates to roughly 5 tons of supplimental feed which is probably about 2 tons of manure and 2,000 gallons of uria per season. Any takers?

Oh forgot the 10 feeder pigs I run June to November... 2 tons of supplimental feed 1200 to 1500 lbs of manure... 1000 gallons of uria. Using them to slowly take back field edges for pasture

Matthew, if you read the scientific literature on the relationship between organic amendments and soil pH the results are mixed. Generally speaking organic decomposition is an acidifying process. However, 'manure' is not a uniform product like RC Cola, and different manures can have different effects in the same soil. Poultry manures will often result in a rise in pH, particularly layer manure, presumably because layer feed contains lime as a calcium source. However, it is a long long way from 5.0 to 6.5, and I would recommend that you lime it heavily to get things going in the right direction, then do regular soil sampling to see what effect your manure is having over time.

Animal manures are alkaline and will raise a soils pH.

Never add lime to a soil without the guidance of a good reliable soil test, guessi8ng at the amount needed may well result in nothing changing or and excess amount of lime which is just as bad as too little.

Kimmq is kimmsr

Gents thank you for the thoughtful comments. Several soil tests done at multiple locations on the property where I'm looking to grow pasture or small plots of vegtable/grain. All are giving me right around 5.0 pH and very nutrient deficient, hi percentage of Magnesium as well (low calcium too which makes sense). It really doesn't matter the quantity of NPK when the crops can't utilize them due to soil pH... Well except the blue berries I just planted.

I'm thinking I'll lime my garden and every other plot and compare the differences between last year's baseline pH and this season's limed and "unlimed". I'll pull soil samples this fall. I'm planning on cover cropping with Rye and crimson this fall.

Cheers

Matthew... I'm just curious, did a lab do the testing?

Yes, midwest labs

Couple of thoughts; for pasture a pH of 5.8 to 6.0 is considered optimal. Grasses are fine with low pH, but clovers are not, but do not respond above 6.0. Vegetables of course like it a bit higher.

Calcium has nothing to do with pH. Lime is calcium carbonate, and it is the carbonate that reacts and nutrilises the acid. If you used magnesium carbonate for example you would get the exact same result.

if you lime in the spring and test again in the fall, it will likely somewhat underestimate your change in pH. As a general rule figure about 50% of the lime will react the first year, and the rest will mostly react in decreasing amounts over the next few years.

Okay. From what I've read... My calcium ratio is very low. Didnt know that calcium cabonate had nothing to do with calcium as an element in the soil. Completely separate matter then... I need to be able to grow a grass legume mix for my pasture so I need to eventually get the PH above 6.0. Interested in a small mix of alfalfa to help as well... Thanks for the thoughts...

Oh one further question... So the carbonate reacting with the acid would then leave the calcium left over for the soil? I've read that the right calcium percentage can help with tillage issues (clods of clay)??

Years ago (1930's), there were competing theories about plant nutrition; one theory was that if all the nutrients were in the proper ratios the levels of the nutrients were not important, and plants would grow at their maximum potential. The competing theory was that the ratios did not matter as long as there were sufficient nutrients available plants would grow at their maximum potential. In science the ratio theory was found to be unfounded and was subsequently abandoned, pretty much completely by the 1960's. So science and commercial agriculture operate exclusively on the sufficiency theory, again because it has been conclusively proven by experimentation thousands of times over many many years. Regardless, many soil gurus, salesmen and other 'experts' still tout the ratio theory which has developed what can only be described as a cult following. In practice, if you use the ratio theory things will grow fine, you just end up adding excess nutrients, usually calcium, to maintain the 'perfect ratio.' Commercial growers do not do this because on average it costs 50% more to maintain fertility under the ratio theory with no increase in production. Having said all that, there are a few exceptions; the bases (Ca, Mg, K and Na) compete to a degree for uptake, and if the ratios is way way out of whack you can induce a deficiency, but this extremely rare in typical ag soils. In summary, people will argue until they are blue in the face that the ratios are important, and I don't really feel like arguing with them, but they are in fact wrong.

So no, the calcium in lime has nothing to do with the change of pH, but since lime is half calcium you get a lot calcium with it. Superphosphate also contains a lot of calcium (35%?) as do some other fertilisers, so typically between liming and general fertilising you usually end up with more calcium you actually need. Note that dolomitic limestone (dolomite) also contains magnesium carbonate, so typically if someone needs magnesium they will use a dolomitic lime if it is available because it is a cheap Mg source.

I have heard people say that calcium helps with soil structure, but have never seen anything along these lines from a credible research source so I suspect there is nothing to it. The thinking likely stems from the remediation of high sodium soils. The sodium destroys soil structure and calcium sulphate (gypsum) is added to fix them. The calcium replaces the sodium in the soil and the structure improves. They don't use lime for this because the pH of these soils is already way to high. The best thing for improving the structure of pretty much all other mineral soils is organic matter. Practically speaking this means green manure crops and/or pasture.

Getting a bit long winded here, but if you are going to have lucerne in the rotation a higher pH is more desirable, 6.5-6.7 being adequate.

PH is a measure of the free Hydrogen ions in soil. The more of these ions the lower the soils pH. Lime, Calcium Carbonate, is added to soils to help counteract those free Hydrogen ions and by attaching to them raises the soils pH.

Most all grasses prefer growing in soils with a pH in the 6.0 to 7.0 range which is why most soil test will recommend adding lime to correct a low soil pH.

kimmq is kimmsr

Kim, if you look at the research you will find that in general pasture grasses are fairly acid tolerant and depending on the specie will not respond to pH increases above 5.0-5.5. Pasture pH is maintained around 6.0 for legumes, not grasses.

Re: calcium improving 'soil texture': it works if you have clay and if that clay is a sodic type of clay, meaning it has a lot of sodium attached to it. I would think potassium based clays as well. Ca++ works by displacing two Na+ or K+ ions on the surface of the (very tiny) clay particles, and one Ca++ can actually sort of glue two clay particles together that way. So the particles get a bit larger, which makes the soil act more like silt and less like clay. But it doesn't work in every type of clay. Mine, for example, is basically degraded limestone and has lots of Ca in it already.

Tox...,

Yeah, not only are my soil's pH and NPK off, but my tilth is very poor as well (where bare there are large clods of soil when wet and hard as a rock and cracking when dry). I figured cover crops might help my tilth, but trying to get "hardy" covercrops to take has been tough going, except for portions of the soil where I ran turkeys, broilers, and egg layers last season (...orchard grass, fescue, rye and even Lucerne/ crimson are green and growing better (not very thick yet though).

My soil is Caroline Silt loan (class 2) moderately well drained. Had stands of nasty sand pines on it. The soil does have higher percentage of clay as well. Magnesium is 18% and calcium is 38%... Thanks!

Oops... Sorry sodium is 2%

Hard clods certainly says clay. Have you considered just covering with layers of compostables? If soil won't grow anything, just cover it with sheet compost piles until weeds begin to grow pretty well. I've done this in an area of terrible clay that is too shady to get grass growing in such poor soil. Don't really want to invest the time and effort to till in a bunch of compost. I laid down cedar branches (any sticks and twigs will work) to hold the mulch on the gentle slope and covered it with free wood chips. I'm just going to maintain it with grass clippings or leaves or more wood chips for a couple years. May not take that long. It keeps it from being muddy and the worms are doing their thing underneath.

I've actually started doing that already. I purchased a large amount of finished compost for our garden, orchard, etc. I top dressed about 10,000 square feet with it just to see how it would take. Lots of grasses and legumes have started growing already. Not very practical for 8 acres however... One of the hay properties down the road has 40+ rotting round bales on it (2 years old I'm guessing). I was thinking speaking with the owner about taking it off his/her hands and dropping a bale in the bare areas around the property. Was thinking I could cut the the twine and fence my 50 layers in around each one and let them pick thru and scratch it around for a week at a time. We already get 2 to 3 loads of wood chips from a local tree service delivered each year, but, most of that goes towards composting farm by products such as broiler and turkey left overs after butchering. I'm thinking I'm on the right track with this as I've seen steady progress with the mulching and composting. It obviously takes significant time and I'm not sure it is helping the overall structure of the soil and pH. Meaning I'm not sure the depth of the "mulching's" effects on crumble to aid in better drainage. I had considered a more invasive mechanical means to quicken drainage improvement, by utilizing a keyline plow. 2 to 3 spades about 2 to 3 ft apart set 12-18" deep. No turning of the soil here just creating small channels in the soil that deep rooted cover crops could be seeded in. Over time the roots of the cover crops would take hold in the channels and begin to improve tilth and crumble. However, if my pH is out of wack those cover crops will probably not take requiring lime. I'm not against liming, but midwest labs' recommendation is 7-9,000 pounds per acre to get it in the 6.5 - 7.0 range!

In our area, agricultural limestone is $6-10/ton. 3 tons/acre would then cost $18-30. If your area has similar prices, I'd suggest getting a pickup or trailer load or two and spreading it around, seeing how the pH changes, and then proceed with more if necessary. Lime can take a while to work, but the initial dosage might be enough to allow you to grow some of the cover crops which could further help your soil.

Renais

fertilizersalesman, yes grasses will grow in soil with pH levels in the 5.0 to 6.0 range but they will not grow as well and unwanted plant growth (aka "weeds") will grow in as well. In turfs growing in a good healthy soil with the pH in the 6.0 to 7.0 range those grasses will grow in denser and that will help keep those unwanted plants to lower levels.

There was a study done that found that spreading lime, at a cost of $240.00 increased yield from a hay field by $80.00 in that one year, qand did not think that very cost effective. Apparently the studier did not take into account that the liming would last 5 to 7 years and the yields would increase for the same time meaning the actual increase in yield for that time (5 years) would be $400.00 making the application of lime more cost effective.

Bluegrass, Perennial Rye, the Fescues, most all of the cool season grasses will grwow better in soil with a pH in the 6.0 to 7.0 range, and pasture grasses will as well and will be more nutritious.

kimmq is kimmsr

32 tons of lime wew...

Alright Kim, you made me look; yes, the general recommendations for ryegrass call for a pH of 6.0-7.0. However, I just breezed over half a dozen papers that all said there is no measurable response above 5.5-5.6. What that is saying is that they grow just as dense and just as fast and that there is no measure able difference.

Post a link to those papers. I woulde be interested in reading them since
I do not find them on any web search I do.

kimmq is kimmsr

Kim, I don't really feel like repeating that exercise, but grabbed a few quick links (see below). Again, as I stated above most recommendations will say the ideal pH is 6.0-7.0, I am not arguing that. Things to keep in mind: if you look up turf/lawn recommendations they are aiming for aesthetic perfection and will always recommend maximum everything. Turf is managed as a high input low risk system. If the pasture is in rotation with other crops, pH has to be maintained for those crops. Pasture is managed for an economic return and thus the objective is to use as little inputs as possible. Note that what we are discussing here is pasture. That being the case, with most grasses there is no response (or insignificantly small response) above 5.5 to 5.6. Pastures with legumes are typically maintained at 5.8-6.0, because there is no response above this. This is the way it is done in the real world, and it is done that way based on science. You can find evidence to support whatever you want, but again, generally speaking, there is no response from grasses at pH's above 5.5-5.6.

If Matthew was talking about his lawn or garden plot, that would be one thing, but he isn't, he is talking about liming several acres. So again, in my opinion he should make his best estimate based on his soil tests, and target a pH of 5.8-6.0, then soil test next year and see how it went. If he is planning to grow alfalfa he should aim a bit higher. That is the logical thing to do.

http://extension.oregonstate.edu/tillamook/sites/default/files/documents/dairy/dairy-soil-ph-and-pasture-productivity.pdf

http://www.dairynz.co.nz/media/255831/7-15_Lime_and_soil_acidity_2012.pdf 

http://cropandsoil.oregonstate.edu/system/files/u1473/Report3-SR10-01-HartandMellbye.pdf

The New Zealand page could not be found. The other two seem to be about the same study, and they do indicate that yields did improve by liming.

If one had to pay $225.00 per ton for lime it probably would not be cost effective to apply any to land with soil pHs in the 5.0 to 6.0 range, but as I stated before the soil pH in my property came up simply by adding organic material to that soil. The primary cost to me was the gas needed to haul the organic material from where it was to where I wanted it and I needed to go that way anyway.

Most soils I have looked at have been not very good due to a lack of adequate levels of organic material.

kimmq is kimmsr

Kim,

Thank you for the and encouragement. I'm not in a huge hurry and organic material something my property has plenty of. Along with the free wood chips I get I have plenty of brush, lead litter and brown/green manure. The costs of getting them where I need them is mainly labor. Most of which is animal labor not my own. For the small crops I plan on growing in the short term, a little lime would help to increase my vegetable yields which are mainly for personal consumption.

Oh I forgot... My soul samples are showing 4-5% organic matter.

Thank you all again for the comments. Great means of communicating ideas! I will keep you all up-to-date over the next few seasons.

Matt

www.yardbirdfarm.com

Great Mills, MD

Kim,

That page isn't coming up for me now either... not sure what to say about that. I hadn't noticed the other two were from the same place and shared an author, good eye. However, they are different; one is talking about the coast and the other the Willamette Valley (where most of the worlds ryegrass seed comes from). But the theme is fairly universal as I have been saying, most grasses do not respond above the mid 5's.

The problem with amendments like you said you have used is one of scale. You can dump heaps of organic material in your garden and get good results (I do). But when you scale that up to farm level it quickly becomes impractical, and lime, even at $225 becomes a better option. The amount of compost and leaves and grass clippings and pea straw etc that I dump in my garden would be the equivalent to hundreds of tons per acre, and again, that is not practical. If you want to build organic matter on a large scale you have to grow it in place, and that means grow as much biomass as possible using lime and fertiliser, and do as little tillage as possible.

That Oregon study is the same one I referenced in my post above. and both articles refer to the same study.

kimmq is kimmsr