Raven, I have no experience with blueberries or low ph soil. My experience in the fertilizer business has been that dry sulfer is the cheapest. If I remember right dry sulfer comes in a 90% formulation. Ammonium sulfate adds some, but you would have to use a LOT of product compared to just using dry sulfer. You can not dissolve Dry sulfer into a slurry though I don't think. If you want to go liquid it comes that way, but it costs a lot more. Here are a couple links for you. http://www.algreatlakes.com/PDF/factsheets/ALGLFS28_Reducing_Soil_pH_Field_Crops.PDF http://www.tigersul.com/products/agriculture/bentonite-sulphur/tiger-90-cr-sulphur.html To truly amend an 1/2 acre of 6 ph down to 4.5 you would need 855 pounds of a 90% dry sulfer, with a cost of $300-400. It would take 5900 pounds of ammonium sulfate ($1200-2000) to do the same thing, and adding that much AMS would add a lot of nitrogen and Im not sure if you would need that or not. Around here you could find a dry fertilizer outfit to bring a spreader out if it was a big enough job. 1/2 acre not so much. But I bet it could be done as an experiment even with a yard spreader, or some kind of pull behind a 4-wheeler spreader. It would just take some math to make sure you got it spread right. It would need incorporated, either with rain or mechanically. If my calculations are right it would take 296 gallons of a 26% liquid sulfer product to amend 1/2 acre from 6 down to 4.5ph.

Contact your local office of your state universities USDA Cooperative Extension Service about having that done and then dig in with these simple soil tests to see what you have. 1) Structure. From that soil sample put enough of the rest to make a 4 inch level in a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and replace the lid, tightly. Shake the jar vigorously and then let it stand for 24 hours. Your soil will settle out according to soil particle size and weight. A good loam will have about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%) of organic matter on the top. 2) Drainage. Dig a hole 1 foot square and 1 foot deep and fill that with water. After that water drains away refill the hole with more water and time how long it takes that to drain away. Anything less than 2 hours and your soil drains too quickly and needs more organic matter to slow that drainage down. Anything over 6 hours and the soil drains too slowly and needs lots of organic matter to speed it up. 3) Tilth. Take a handful of your slightly damp soil and squeeze it tightly. When the pressure is released the soil should hold together in that clump, but when poked with a finger that clump should fall apart. 4) Smell. What does your soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant odor? The more organic matter in your soil the more active the soil bacteria will be and the nicer you soil will smell. 5) Life. How many earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5, according to the Natural Resources Conservation Service, indicates a soil that is not healthy.

Sorry for not getting back sooner! Thanks for all the info. I am not a new gardner but I am new to this particular area. I am used to gardening on the coast of California and this is inland, Mariposa. So it's much hotter and has alot more freezing days. I talked to the extension person who is from UC Davis at the Mariposa County office. He confirmed that the area is in fact low in phosphorous. Although, if the kits are not that reliable, it might not be as bad as my test was showing. He said that he has a kit that I can come by and get. So it sounds like unless they actually do a lab test, another kit might not be reliable, either? Even if the extension office is offering it? Thanks for the recommendations on which cover crop to do. In the past, I have only done fava bean covers and I only have so much time to research everything before fall. The only thing that seems weak is our corn. It seemed to get really stunted and the cobs low down. However, driving through the Central valley this weekend, I was looking at the fields of corn. If you look at a whole field, it seems quite tall but if you look at a stalk individually, they seem actually not too different from my own. But maybe that's just the stalks on the edges. Corn is one thing I have not grown before. Our cucumbers were awesome... wet, sweet and crunchy. That is until the rabbits decimated the plants. So now we have, hopefully!, more rabbit barriers. We have 1" wire along the bottom and then laid out in front of the fence. We did not dig down as our soil is a hard clay and so hard that in parts of it, you have to use a pick ax and a whole lot of muscle to break ground. I am hoping that the rabbits will see that trying to burrow through such hard clay is a waste of energy. We actually still live on the coast and go to the property on weekends, holidays, etc. So the garden is on a drip and we won't know until next weekend if the rabbits are out. Does anyone know of any labs in the Merced/Los Banos area? Or can you mail samples to labs? Is there a risk of that?

I love making soil. I love it even more when someone else is doing most of the work for me. I'm itching to start some spring planting in my tiny garden, but it's technically still a bit early (our last frost date is supposed to be around the 18th or so, but these days who even knows) and I'm impatiently waiting for the contractors to show up and replace my rotted fence before I can do any planting in the back half where the pile of rock mulch over weed cloth used to be. The fence would have rotted anyway, but the bottom of it was completely eaten away where the rock mulch was piled against it. I have already put down a tiny new tree (Amelanchier x "Autumn Brilliance") which arrived bare root and needed to go in the ground ASAP, but it's not next to the fence, so it should be fine as long as the fence guys don't step on the 18 inch high forked stick which, seen with my eye of faith, is already a handsome small patio tree. The tree went in the spot where the old, scrawny, unhealthy cherry plum used to be, where I have been piling vermicompost and leaves ever since last summer. I didn't amend the planting hole at all - just dug and filled in. Enough leaf mold and vermicompost just fell into the hole to make me feel fine about the start my new tree's roots are getting. Anyway, the "someone else" who is working for me outside is a healthy passel of earthworms, which I can see out there every time I pull back last autumn's leaf mulch, which I diligently collected from the sidewalk in front of my row house and brought out back. Even if I can't set to work yet, I like knowing that they're hard at it. I've seen some of my red wigglers who rode out from my indoor worm bin, and at least three separate species of native earthworms: slow gray short guys, some really huge red nightcrawler types, and a longer, thinner, super-active wiggly worm that's new to me. I've also scattered out some seeds and grains for the sparrows and squirrels, inspired by some videos of composting chickens I've watched on Youtube: so there's been lots of pecking and scratching and digging going on in the layer of leaves, which is both fun to watch and will serve to further shred down the leaves for incorporation in the soil. When I do get to the planting along the back fence, I'll try to remember to post a soil pic as a "before and after" to the one at the start of this topic.