Excellent... thank you, SO. I think chemistry was my worst subject in high school, so having you summarize that simply and plainly is much appreciated! No danger of getting our soils anywhere near 6, eh? lol We must have excellent buffering qualities (hope I'm using that term correctly), though, because the efforts to lower pH here seem to be sticking better than areas such as daninthedirt is speaking of (great username, by the way, Dan). I also have a rather easy time lowering water pH for our aquarium fish; half distilled and half dechlorinated tap water keeps it in a comfortable range for them without having to purchase adjusting chemicals. (We're now on the river water pipeline that goes into town; well water was much, much worse and I could only use a small amount mixed with the distilled.) We're rural in the Humboldt area, but we have family who is mixed farming the Young/Allan area. :) Prairie Garden Seeds is in Humboldt here and I met Jim and his family briefly when I picked up a seed order last year. Nice folks. I should ask for a tour of the seed gardens someday. One more question. Our garden has flooded before. How long does it take for the iron to then get back to an unavailable state after such an incident? So as not to hijack crabbygardener's thread any further (sorry about that), I'm going to spin off with a new post over in the soil forum regarding my question about zinc and copper. This post was edited by macky77 on Sun, Mar 16, 14 at 11:29

I'm posting on this OLD post because it still comes up at the top of google search for "citrus peels lower soil ph" ... I have been doing tests with Citrus Peels.... I have found that about 30 good size grapefruit peels blended up in a blender (lots of batches of blending) with half water/half citrus in the end, produces a good acid base. I did enough to fill 30% of a 5 gallon bucket, which I then diluted to a full 5 gallons of liquid. This was then diluted 5 fold to register a drop in pH of 1 for the water... This diluted citric acid can be used similarly to sulfuric acid dilute. There is a company here that sells Moon Juice which is a combination of sulfuric acid + iron and other trace minerals... It's used for temporarily lowering the ph so trees and shrubs and such can uptake iron and other minerals that lock out at alkaline pH Levels... Given that we're in the southwest we have an ABUNDAND supply of citrus and over time, this is the same effect the trees fruit would give to the soil if there were no humans to tend to and pick the fruit... the fruit would rot on the ground, the citric acid would leach out into the ground as it decomposes and maintain a more acidic soil balance for the trees long term support... So can you use citric acid to dilute, yes you can, though, just like with a sulfuric acid dilute, you're going to need to apply it regularly (monthly or so depending on ph plant/etc) until the bacteria that feed on the sulfur have had enough time to lower the soils actual ph levels ... Something that seems to be long forgotten as I read some of these posts is... all living things have a pH, you can burn things by dropping ph too fast, or by raising too fast, so obviously some of the responses regarding putting acid next to the roots are appropriate, they are also inappropriate because your obviously not going to dump straight acid on anything unless your intention is to utilize the full strength of the acid :P Good Luck! Would love to hear about what you've done and how it's developed since your original questions!

Thanks to everyone for the interesting responses. dirtydan, have you had a soil test done to determine why your pH is so high? Unfortunately there is no one in this area that will do a soil test for less than $70 per sample. I recently found a link to University of Mass Amherst that offers soil tests for $13 so I am planning to send them some samples. http://www.umass.edu/plsoils/soiltest/soilbrochure2009.pdf I use home test kits for nutrient and pH. I also have a Hanna pH meter that comes in handy for quick tests. I don't know my native soil composition. Its pretty bad though. It could be described as dense gray clay with some occasional small pockets of white material. When dry, its is normally cracked and coated with a layer of frosty looking crystals that taste like salt. The salty crystals grow up the side of masonry, concrete and stucco walls. When wet, it turns to a slippery slime that will coat the bottom of your boots with a couple pounds of thick clay. It has no vegetative matter whatsoever. I have been prepping my raised beds with compost, sand, clay, fertilizer and various sulfur products to lower pH. Where are you in the Mojave? I am located in the city of Lancaster, CA. This is the high desert north of Los Angeles at about 2,400 ft elevation. We only get about 5 inches of rain per year, most of it is in February. In fact we will probably not see any significant rain here until next fall or winter. The arid conditions are one of the reasons for the high soil pH and lack of organic mater, also the fact that we are almost entirely dependent on alkaline municipal water for irrigation. What are you trying to grow that is having trouble? When I first moved here I put tomatoes, squash, cucumber, melon, and several others in the unamended native soil. They were all killed or stunted from the salt or nutrient deficiencies. Iron chlorosis and micronutrient deficiencies were evident in the plants that didn't die immediately. The only exception were some tomatoes that I managed to save by side dressing with aluminum sulfate and a highly acidified nutrient solution, they remained quite stunted however and suffered from BER. Since I have built raised beds and worked the soil, I have a productive garden and only seem to have problems with cucurbits in beds that have been freshly sulfured, and typical aphid and leaf miner infestations. There are two main reasons as to why sulfur is the preferred material for acidifying soil. 1. Economics Sulfur is one of the most plentiful and inexpensive elements on earth, said to comprise 2% of the mass of the earth. Sulfur is a byproduct of oil and gas refining and there is a massive oversupply of the material, especially in Canada where its is extracted from oil sands during refining. High concentrations are not toxic to vegetables. Cucurbits being the exception. Avoid sulfur contact with the leaf surface of cucurbits. Other possible acidifying agents (some impractical): ammonium nitrate liquid nitrogen urea diammonium phosphate acetic acid hydrochloric acid HCl (also called muriatic acid) phosphoric acid Elemental sulfur has been used for centuries as a fungicide and miticide. I don't know if, or to what extent, it affects beneficial soil fungi. I suppose that a reduction in soil fungi is OK as long as our vegetables are not negatively impacted, and there is no damage to the environment. Once the sulfur it oxidized by soil bacteria I would speculate that soil fungi will return to pre-application population size.

seysonn, that's a good point you make. If neutral distilled water won't make a noticeable difference compared with tap water, then the only problem I have is finding a reliable way to test for pH. I thought my cheapo test strips might be off by a little bit, but the vinegar test does show them to be worthless. So what is the liquid test kit you're referring to. What brand is it?. I've been looking at better quality test strips, ColorpHast is a good brand (used by my scientist friend) , and also Phinex (4.5-9 pH range). I'd like to find some with a range of 2-9 pH so I can use vinegar as a low end standard. ColorpHast makes that range, but seems to be out of it every time I check. And does it matter if a test kit is labelled for saliva and urine...is that just because of the range, and can any pH test kit/method be used to test a soil sample? Any opinions on favorite pH testing methods? I think I'll start a new thread to ask that questions, or has this been done many times already?