How do I neutralize an alkaline soil?

I recently took the pH of my garden soil, was shocked to see it ranged between 7.4 to 8.0! Last year it was a first year garden, for about 10 years before that it was just yard, and for decades before that it was a hog and sheep barnlot. I live in north central Indiana and live close to a river and have sandy soil. My research has led me to several ways to raise the pH, but I need to lower it (hoping to get it to 6.5). What product should I use, how much and how often to get my soil more acidic?

Unless you want to grow the few plants (e.g., ericaceous plants) that actually require acidic soil, there's really no need to change the pH of your soil. The vast majority of species are quite insensitive to pH, and do fine across the range of normal soil pH. As a case in point, high pH soils are perfectly natural and normal through a broad swath of the central continent, and I grow well over a thousand species in soil that has a pH of 8.

Adding organic matter to the soil will make it a bit more acidic.
It will also help sandy soil to hold more water.
It will also help the plants by holding nutrients.
It will also help by encouraging microorganisms in the soil. Most are beneficial.
Organic matter can be from fallen leaves, lawn clippings, plant based kitchen waste and similar materials that you compost.
Organic matter can be from 'green manure' crops that you grow then 'til under.

I would mix up to 50% organic matter with your soil for plants that come from the forest floor, or about 33% for plants that thrive in the sun. For example, if you lay 3" deep then rototill with 6" of your sandy soil you would end up with 9" that is 1/3 organic matter and 2/3 sandy soil. Plant, then mulch with an inch or so of fine material, or a couple of inches of coarser material. Over time this layer will decompose and replace some of the material that you mixed in as it decomposes.

Have you done tests for nitrogen, phosphorus and potassium?
How about salt?

At the site of an old feed lot I would expect fairly high levels of most fertilizers and salt from the animal feed.
But sandy soil does not hold these things very well, so I would sure want to test to see just where the soil is.

No Diana, I haven't checked the nitrogen, phosphorus, potassium or salt. I will do that ASAP. Thank you so much for the info!

Adding compost will help to neutralize the PH. Esphoma makes a soil acidifier. Always follow lable directions.

The most commonly used method for reducing soil pH (making it more acidic) is sulfur. It comes in various forms and products easily applied. It, used in conjunction with lots of neutral, quality compost easily solves the problem. However the change is not an overnight one and patience when it comes to results is required.

I have to disagree a bit with some of the comments made above about the tolerance for most plants to alkaline pH. It is an issue I have had to work with for most of my 50 years of gardening life. The problem isn't the pH itself, the issue is the effect the alkaline pH has on nutrient uptake by the plants. It retards uptake in even the basic nutrients like N-P-K but especially affects the needed micronutrients.

My native soil is 8.4+ and if I didn't acidify it I would have chronic issues with magnesium, boron, copper, iron, calcium, etc. deficiency issues in most all my vegetables. Learned this the hard way many years ago. These deficiencies show up in the plants in various ways, some more severely in plants like tomatoes, potatoes, peppers, and squash but can affect both plant health and production in all species.

So while it is relatively easy to adjust soil pH and I am more than convinced it should be done, it does call for careful annual monitoring. Sadly most of the home test kits are grossly misleading in results so I always recommend you first start with a professional soil test (contact your local county ag extension office for this) and plan to invest in an inexpensive soil pH tester for future use.

Hope this helps.

Dave

I have had the same experience as most of the others have posted. I have very alkaline soil and water, bc I'm on a Well. I have never had any issues with it in the 20+ yrs I've gardened here. Nobody in my area adjusts the pH and we all have very productive gardens. A pH of 8 is not that high. Until I joined DG I never knew it could be an issue, bc I never had any problems.

8.0 isnt really that much out, above that, it can cause uptake issues, usually not using standard pkn ferts, but finding the SPECIFIC pkn of the plants needs helps 98%, of most issues. If you have sandy loam, then your ph is prob going to be in constant flux. What plants are you wanting to grow that needs so lo a ph?

The mainstay of my very large garden is Acidic plants like Rhododendrons, Azalea's Tulip tree's, Elder, Camellia, Magnolia and many more, I live in a coastline where RED Sandstone is the dominant type of soil. It's very sandy, cant hold onto much moisture (even though we have a high rain count ALL year round) I have to add plenty Peat to the soil to help build up the structure of the soil and allow air and any other nutrients to stay in the soil structure long enough rot the shallow roots of most of those plants to remain happy within the environment I can offer and these plants require.

To make the rest of my growing area (flower beds, veg beds etc) I add heaps of animal manures, home made composts and IF need be, scatter handfuls of Pelleted Chicken manure, as well as adding some garden lime scattered over the soil as a light dressing in winter, Our rain and cold helps take the Lime down under the soil where it is required.this helps make the garden beds more sweater and the harsh weather helps break up any already cleared and dug over soil.
All these additions help adjust the PH of the soil, either higher or lower depending on the plants you need to grow.

There are some plants that will tolerate a slightly higher PH than they really want, BUT for acidic plants, you really do need the correct the PH to below 7.0 or below, Dont add any lime for acidic plants,
For any members of the Brassica Family (Cabbage etc) they need a more Alkaline and a soil best above 8.0 -or 10, to get that add as much Humus /manures etc as mentioned above to keep this level of higher PH, by adding all the Humus / Horse manure well rotted is best, Home made compost is great too, dig this into your sandy soil and you will find more or less instant improvements to the condition, the water retention, the air cooler conditions and the feel of the soil is all good.improvement IF you want to raise the PH, IF you require to lower the PH, get loads of well rotted pine needs etc BUT best of all, as much Peat as you can get as this will help hold onto moisture, improve the retention of any feed the acid loving plants will require too.

Dont be confused with the difference between Peat as an organic matter,, and composted Animal or Veg manures, they both have different types of helpful matter, Peat will LOWER PH while the rest will heighten PH levels.
You need to determine what you want to grow.

It Gets quite confusing and I hope that between all the replies, you can get a little bit of understanding of the different types of soil that suit's the plants you fancy growing. I have wasted loads of money over the years by NOT suiting the plants to my soil type and believe me, there is nothing more disheartening than to watch your plants die on you and find it was a no hoper to grow in my soil in the first place, Older and a little wiser now.
Good Luck and take your time, just enjoy making your new garden.
Kindest Regards.
WeeNel.