I don't worry about it, at all.

Many fertilizers are acidic, but they don't seem to result in any significant pH change. The rain is strongly acidic as well and this hasn't eliminated alkaline soils.

The earth has a lot of buffering capacity in most cases and a little fish emulsion isn't going to have much impact on that. Even lime and sulfur are only able to shift pH for a limited time. Stop applying it for a few years and pH drifts back to where it was previously.

In most cases the pH of highly organic soils isn't very relevant to plant health or nutrient availability. It's the strongly mineral soils lacking a significant organic portion where pH is more of an issue. Those with more of a chemistry background can explain the whys.

No matter what organic matter you have, pH does matter. Just because you have a lot of organic matter doesn't mean you can let pH run to 9,10,11,12 and be ok... Maybe I didn't understand you correctly?

I would not say a pH of 12 is OK. However the fish emulsion is not something that is going to overwhelm the buffering capacity of soils.

The principle is the same with the acidic rain. The soils do not experience a pH shift of any significance.

A trick used by growers of acid loving plants like blueberries is to add sulfuric acid to the irrigation water and home growers often use vinegar. Both are acidic, but neither actually changes the soil pH perceptibly, they simply result in flushing acidic water (temporarily) over the root zone. The buffers in the soil then neutralize the acid and that's the end of it.

The point about organic matter making pH less relevant is that nutrients aren't tied up in organic matter due to pH to the same degree they are in mineral soils. I wouldn't carry that to the extreme of a pH of 12, but there is a much larger pH range in which plant needs are met in organic soils versus mineral only ones.

Again, someone better versed in chemistry will have to explain the technicalities.

One last point, many gardeners amend soil with peat moss and it's very acidic stuff, often in the 4.0-4.5 range. Because it is organic rather than mineral it doesn't result in the poor plant performance one might think such an acidic material would. The issue of pH is more relevant to soils lacking in organic matter than they are to organic gardeners as well as container gardeners whose growing media is largely organic matter such as peat or bark.

You asked the same question last year. It's not a problem.

So- how do you deal with it? Don't think about it.

Here is a link that might be useful: pH of fish emulsion

"One last point, many gardeners amend soil with peat moss and it's very acidic stuff, often in the 4.0-4.5 range. Because it is organic rather than mineral it doesn't result in the poor plant performance one might think such an acidic material would. The issue of pH is more relevant to soils lacking in organic matter than they are to organic gardeners as well as container gardeners whose growing media is largely organic matter such as peat or bark."

That's news to me, I'll ask my soil sci professor for details, I'm interested to know why that would be.

Thanks

Hi hoorayfororganic...do you enjoy gardening...:-) Franklin

yes

OK, the fish emulsion is acidic. If you put one tablespoon in a gallon of water with a 6.8 pH you won't have an acidic solution. Then you distribute it on 100 sq ft of garden with a soil pH of 6 to 7. The acidity of that small amount of fish emulsion is not a factor. It's a matter of dilution. Tom

You have people that use it all the time and it's never an issue. Believe it.

It's not all really as complicated as purists would have you believe.

One tablespoon of fish emulsion in a gallon of 6.8 ph water will actually make it quite acidic, definitely below 6, probably closer to 5. If you use 2 tablespoons per gallon, then the pH will be below 5 - I know because I test my pH.

I found that using nutrients regularly without pH-upping the water resulted in terrible pH swings for me, based on my own pH testing. If you fertilize once per month, not much of an issue, but if you are fertilizing more regularly with liquid nutrients then you might want to consider it.

Regarding the acidity of peat moss and it still being a great amendment - this is misleading. If you look on the back of ingredients of peat-moss based soils, such as Fox Farm, you will see dolomite lime as one of the ingredients. Peat-based potting soils typically have dolomite lime added to balance the pH, and they typically let the lime break down a bit too. If you do research on amending with peat moss, you will see that you should add some lime to balance the pH. One of the benefits of using coco coir instead of peat moss is that the pH of coco coir is 6.0, so you don't really need to balance the pH when amending if you use coco. I use peat based soils to start with but use coco for the amending for this reason.

Simply having alot of organic material in your soil will not make pH swings a non-issue. My plants were displaying nitrogen deficiencies, so I kept feeding them more nitrogen, not realizing the nitrogen was lowering the pH so much that then they couldn't even absorb much nitrogen, resulting in the nitrogen deficiency. I began making sure the pH of my nutrient solution was on point and then the problem began correcting itself.