If an organic fertilizer is having a low pH, ( how much low , you ahve not emntioned ), it is good for soil having alkaline pH more than 7.0. Some punchline is missing from your question , please elaborate more on the content of your question . What is the pH of your organic fertilizer and to what kind of soi s, you are looking to apply...

Excellent reply by Dr. Anoop. Low pH organic fertilizers are great for Alkaline soils of arid regions. In the case of acid soils, really depends on what is the pH of organic fertilizer and the soil.

Good luck

Nice question but it needs more clarification about soil type, accurate ph range and then the recommendation can be given.

thanks all for your suggestion, the organic fertilizers is having pH 4.68. the type of soil is not decided yet, but we try for all types of soil and crop. and for all crops we need to add some thing which can improve our fertilizer and research.

It is very difficult , next to impossible to suggest you anything to such guesstimate feedback . Unless nature and properties of Soil are known , you can't play with pH of organic fertilizer.Can you further elaborate on the nature of organic fertilizer please..?? Are you talk

ing about compost or manure or any other natural source ..??

There is no such organic fertilizer so far developed which can suit to all kind of crops under all kinds of soils..???

Anoop Kumar Srivastava thanks sir, if its not possible to all crops than we try for to implement for medicinal crop mainly. we are not play with pH but try to manage pH according to NPOP standards. we are purely dedicated to society and our goal is to produce organic product which are easily available to farmer with low cost.

Why am i saying this ,since organic fertilizers have their own stroong buffering capacity, changing pH through exogenous application of any aditive will not be desirable at all , unless the soil and crop to be used , are defined ....

Anoop Kumar Srivastava thanku sir, for your valuable suggestion

Dear, Sir,

I believe that, the best way to solve this problem is adding Charcoal since it has many possible benefits not only on crop production but also on soil includes soil pH.

Good point , remains to be seen , by adding alkaline biochar , how does it change the behaviour of organic fertilizer , especially on the baseline micorbial load ...

Adding agricultural lime is the normal and cheapest way to increase the ph. of soils, or soiless media. Although it is slow acting; it is efficient, and realatively insoluble, so its effect lasts for years, rather than months.

I am assuming that this acidic organic fertilizer is a mixture of two or more products. Do not know if it is in a solid form or liquid form? There are some organic and acidic wastes, such as lemon wastes, that can be added to soil or the organic fertilizer to lower the pH if it is basic. I am interested to know if there is any organic substance or waste that is basic and can be added to acidic fertilizer to increase the pH. Lime is good, but I don't know if it is considered Organic or not. Baking soda (sodium carbonate) may also work, but don't know if it is Organic?!

Interesting discussion

Best wishes

Anton is on the right track. Lime (CaCO3, finely ground limestone, etc.) has long been the accepted practice to increase or adjust soil pH. When adding acidic or acid forming fertilizers, one almost always needs to counteract the acidity with lime. Lime (or limestone or sea shells, coral rock, etc) is readily available in many regions of the world and is relatively inexpensive. Its activity depends on the fineness of its particle size (how finely it is ground). The finer the particle size, the more quickly it will react while coarser material will react more slowly.

There are analytical buffer pH methods that can be used to estimate the amount of lime needed to adjust soil pH to a desired level. Or it can be estimated stoichiometrically if one knows how much acidity needs to be neutralized.

Liming is a standard agronomic practice in intensive agricultur.

Usually the way pH would be adjusted to more neutral would be by the addition of finely ground limestone. Soil pH of 6.5 would be a good target. If you analyze your media and it is low in Magnesium I would suggest using dolomitic rather than calcitic limestone. Biochar could also be useful especially if there is micronutrient deficiency issues. Finest of grind is determined by sieve analysis and as previous contributor noted is the coarse material will not be immediately available. Mixing and water and waiting will be monitored by checking the pH overtime. Increments of liming can be monitored and give you exact rates for your purposes.

You can neutralize the organic acids of you fertilizer by adding lime (calcium oxide). The dosage has to be adjusted according to the pH that you measure either with a pH meter or some special colorimetric test papers .

The most common way for adjusting the pH of soil, substrate or compost is by adding lime or gypsum. Moreover, i am not sure but probably you can adjust the choice of raw materials in a way to find an initial mixture that might end up with the pH you are targeting. you are using many types of organic materials as you have mentioned, so probably you can predict the final pH of the fertilizer you are producing based on the pH of initial raw ingredients you are supposed to use. Modification in the choice of such ingredients might be done accordingly.

Rightly said by Zeina.Both gypsum as well as lime could be effectively used to raise the pH of the test material , the amount to be added needs to be decided depending upon the target pH . Prior to that using both the materials , you need to take up a small exercise about the extent of change in pH of test material versus amount of lime or gypsum added, kind of standard curve .Both auger well with organic fertilizer and within the ambit of organic agriculture as well.

For increasing and maintaining soil pH the best reccomondation of 10 tons of organic manures with 2 or 4 tons agricultural lime as soil test on the basic of pH for good crops.

I would suggest lime calcitic and dolomitic are effective for liming but it generally understood that calcium sulfate while being a good source of both calcium and sulfur it has little effect as a liming agent.

See some of these to confirm.

Appreciating very strongly the narration provided by Paul Hepperly , lets try to differentiate the mode of action of calcite/dolomite versus gypsum. While using gypsum as a source material to raise the pH , unless reaction products accumulated within the reaction zone are flushed out of the reaction site , it is very difficult to realise the expected the change in pH . On the contrary , this is not the case with while using calcite/dolomite ( fitting well into the organic practices) . I , therefore , advocate to use calcite/dolomite to use for raising the pH , but as i said earlier , you need to take up an initial exercise , how much to add ,depending upon the pH change , you want to enforce. And additionally , how much nature and properties of your final organic fertilizer , whether or not , experience any change from the original one ( without adding clacite/dolomite), an equally important exercise to deal with. However, this is an ideal pH ( 4.63) of any organic fertilizer to be effectively used for acid soils.

I agree, that that the addition of lime is a good idea to control the pH of compost at a level of about 7 (if we don't exaggerate with lime dose).

However, according to my experience (in Poland in last years and in Peruvian high jungle about 25 years ago), the composts prepared on the basis of vegetal residues (weeds, crop biomass, also coffee pulp) are most frequently neutral or slightly acid (pH 6 to 7). For me it is more difficult to prepare strongly or moderately acid compost (pH of 4 to 5), than the neutral (without lime addition). It seems, that it is possible to achieve it by composting such materials as coniferouous needles, e. g. of Picea abies or Pinus silvestris).

Preparation of organic fertilizer having pH , suiting to acid soils or alkaline soils will not be the end point of this execise. We would need to evaluate such fertilizer under popular land uses under a given agro-pedological conditions to establish effectiveness of such fertilizers. Adjusting pH alone with certain biological materials will be of limited utility , unless raw material on a mass scale is available to ensure its commercial utility.

Lime application could help to maintain a certain pH range

by the addition of finely ground limestone.

Sir,

Lime should not be mixed with organic matter. It is required to mix organic matter with rock phosphate @ 1.0 quintal per ton of compost

Experiment regarding the choice calcium chemicals as well as dose should be performed in laboratory and also in the field as because, all these depend on the nature, types and physico-chemical properties of organic fertilizer and soil in a particular area.