How "fast" is it? I have found articles that say it will take 6-8 weeks, or else "might" be available in the soil for the plants to use within the same growing season, or after about a year. As if that was "fast".
If I'm recommending that they use a liquid phos, say phos at 30 or 59 percent in the formula, in order to push growth of flowers and set fruit on tomatoes, and it is the end of July, is that a better route than the soft rock phos? Because obviously 6-8 weeks while it breaks down in the soil won't get any fruit to set, grow or ripen by the end of this growing season, at that rate. And they want you to add a bunch of steer manure 4 to 8 weeks ahead of adding it to the soil, to help it break down in the soil, and get it to between 6.0 and 7.0 on pH in order for it to work.
I want to grow organic. But the articles seem to state that "side dressing" with soft rock phos won't yield results this year, but that it is "planning ahead" for next year's crop, and even, stays in the soil for five to six years. Some say apply it in the fall for next year's crop, along with organic matter (steer manure); other say side dress when planting for the same year's crop, that it will be available to push in the same season. What do you also say to the organic gardening folks who say that adding starter fertilizer or phos of any sort ruins all the work you've set up for your soil and kills the microbes?
So, if I want to push the blossoms and fruit for the remainder of this same season, do I recommend the liquid solutions, rather than wait forever for the soft rock phos to do something it's not going to do? (This growing season, anyway.)
Valid questions. I have been reading/studying how to increase Brix for the past 2 years, and sometimes I feel more confused than when I started, and the results in my own garden vary. For an example, my peas this year measured Bx14º, yet my only ripe tomato so far was Bx6º. Granted, one tomato is not a fair sampling; and to be honest, it came from a plant isolated from the prepared bed for the other tomatoes and now I don't remember why, or what I used on the soil there.
The methods of Carey Reams and Albrecht seem to be the most prevalent in use, and they are not in full agreement with each other, either. I am coming more and more to understand that it doesn't matter what you use on the soil IF you don't have a hyperactive bacteria system in place so the SRP and other minerals can be processed into the plants. I think my bacterial system is okay, but this week I intend to incorporate a shallow line of inoculated biochar between the rows, and some gypsum (calcium sulfate, which is soluble and doesn't raise pH) as a side dressing, and a quick foliar spray of epsom salts with some molasses...
I also know potassium and phosphorus need to be equal, and available calcium needs to be high. I am learning I probably need to invest in a conductivity meter to measure ERGS... Rex Harrill points out that the whole point of ERGS testing is to evaluate if there are adequate conductive plant food ions to feed the plant at the rate it wishes to be fed. Those who have watched a weed pull all the energy from the soil and stunt the crops next to it have watched the ERGS concept at work.
I know none of my remarks above answer your question, but I'm also not a soil scientist. I'm just a gardener trying to raise healthy, nutrient-dense food. There is a Yahoo Brix group run by Rex Harrill and I learn a few things from them. You might join if you aren't already a member, and pose your questions there...
Each bit of garden has differing parameters, even in the same yard. In my case, my garden is on a limestone shelf, and the pH is 6.4 with a high % of calcium. It seems the calcium isn't very available, though, so I am trying to find out what works best for me. By the way, I generally don't use animal manure on my garden; most of it is so poor in nutrients that it's not worth the effort to locate and haul it home. Instead I continually incorporate lots of green manure from early spring until the ground begins to freeze in late fall, and plant a winter cover crop.