Nutrients and Fertilizers

[D.J. Wolf]

Ok, so here's where I'm starting out. PH test (as always) came back higher than I'd like, a solid 7 or a little more. N is, again as usual, almost depleted. P and K are great, right in between adequate and surplus. This is all done with a home test kit, there is absolutely nowhere near me that will do garden soil tests.

So, What I'm looking at is wanting to lower my PH some, add N, and then add magnesium and calcium, since I'm fairly sure there is hardly any in this soil. My initial plan is to start by working in 1#/100 sq ft (roughly) of Ammonium Sulfate. That should give a good starter boost to my N levels, as well as help with bringing the PH down, I'd guess maybe half a point. Along with that, pre-plant, I'm planning on putting down about a pound/100 sq ft of magnesium sulfate. Now I know, from my dimly remembered chemistry classes and from online research, that this will probably NOT affect the soil PH in any way, even though there is sulfate there. The final preplant addition would be again about 1#/100 sq ft of gypsum, which will provide calcium without raising the soil PH as most calcium products would do.

Now, here's where the questions and YOU'RE expertise comes in .
First off, do my numbers look about right? I know they should be about right for N, and that I'm going to have to continue through the year with a fairly high N fertilizer. It's the magnesium and calcium that I'm unsure of amounts on.
Secondly, in your opinion, should I try to get some additional sulphur worked in to lower my PH even a bit more, like say down to around 6? And if so, how much?

I know I've got a little time here, I've only worked the garden once so far and it was borderline too wet then. Since then, we've had over an inch of rain, with more supposed to be coming this weekend This is starting to remind me of last year almost...

[MrsJustice]

This is why I miss the little hardware stores. you should have a reading level for the nitrogen in your soil. Since I farm all Organic on all levels as Natives by blending Un-used Vegetables and Fruits in my soil during off-season each year, I can not advise you. There is a natural Sulfur that might help https://www.ebstone.org/product/soil-sulfur/
Farmen Joyce Beggs of
Angel Field Heirloom Tomatoes

[Whwoz]

D.J. Wolf, the sulfate will not reduce your pH levels. It is the process of oxidation of sulfur to sulfate that reduces pH. You may be better off by adding composted organic matter to the soil. A pH of 7 to 7.5 is not bad, I had a pH of 8 last season, worked in probably a 3 inch deep layer of compost and the plants did wonderfully well. The organic matter has a number of other benefits for the soil and has a much longer lasting effect than sulfur/sulfate which will leach out.

[RayR]

Originally Posted by Whwoz

D.J. Wolf, the sulfate will not reduce your pH levels. It is the process of oxidation of sulfur to sulfate that reduces pH. You may be better off by adding composted organic matter to the soil. A pH of 7 to 7.5 is not bad, I had a pH of 8 last season, worked in probably a 3 inch deep layer of compost and the plants did wonderfully well. The organic matter has a number of other benefits for the soil and has a much longer lasting effect than sulfur/sulfate which will leach out.

Agree with that. Elemental sulfur takes a long time to oxidize into the sulfuric acid component which is what reduces PH. It's a long gradual process that is dependent on microbial activity. A healthy diverse microbial population is dependent on organic matter in the soil and that can have a longer term effect on actively moderating the soil PH.


Using the synthetic fertilizer Ammonium Sulfate can lower soil PH a little, but the effect is temporary.

[PaulF]

My garden was at 8.5 pH twenty years ago and the soil test indicated applying Elemental Sulphur to reduce the pH. Application was suggested to be applied in the fall because of the time needed to become useable. In my 50'X50' garden 25 pounds of Sulphur was applied yearly for the first several years. As the pH dropped into the 7.6 range the application was reduce to every other year.

Soils tend to return to their historical pHs unless constant care is taken. That is why soil test need to be done on a regular basis. I have used Ammonium Sulphate for the sulphur content and nitrogen application, but Elemental Sulphur and Nitrogen fertilizer is cheaper and more effective. Sulphur is applied in the fall and the N in the early spring.

My total garden is now stable at 7.4 pH and all other nutrients are in the very good range. N is needed yearly for good growth. My mulching program is newspaper base with weedless straw 8" deep on top of the newspaper and that is tilled into the soil every fall for organics which is excellent.

[simmran1]

Joyce Beggs has a great link there, but I haven't seen that brand of products locally.
With that said, I wouldn't be overly concerned with a neutral Ph level. Adding gypsum sounds like a good idea for the calcium. What you could do is find some weathered chicken manure locally or use Espoma from the bag for your N and though it won't do anything drastic to Ph, it certainly won't have any liming effect.

[AKmark]

This is not the piece I was looking for but this is still a good one to understand. It should make sense in your situation pretty fast in regards to a fix. https://www.greenhousegrower.com/pro...-and-media-ph/