EC is a simple test for salinity, the lower the EC the lower the salt in the soil. If you had a high EC you would want to make sure the irrigation water was low in salt to prevent a build up of salt. You have a higher tolerance of salinity in irrigation water than most.

Theniceguy, I assume you mean Electrical Conductivity, which is a broad, indirect measurement of soil properties. It is basically a measure of how well the soil conducts electricity, which tells you something about the soil. EC can be influenced by how much water the soil holds, ions in the soil, etc. As gary mentioned, salts can also influence EC, including common salts in fertilizers like nitrate, ammonium, phosphate, potassium, etc.

Theniceguy, usually with soil test they give you parts per million (ppm) of the major available nutrients (NPK and a few others). If you can give me the ppm for NPK I can give you the recommendations for blueberries from a land grant university. It will be on an acre basis but can be converted to lbs per 100 sq feet pretty easily.

Is the EC of any specific practical value for me in this case?

Gary, believe me, yes, I tried to get a full soil test. Having my wife as interpreter makes everything much, much harder than doing it myself. Apparently the gov offices here only assist with commercial agriculture, so apparently they were doing us a huge favor to have done anything at all. All I got was the pH and EC values I listed. I'm happy to know the native pH at least.

Iiuc, the npk values will fluctuate anyway.

What is a good action plan with the information I have?

According to Growing Fruits and Nuts in the South by Adams and LeRoy, you should apply 1 oz. per plant in March, April, May, and Sept. the first year; the second year 2 oz in March, April 1 oz in May and Sept.; in Third year 2.5 oz in March and April; 1 oz May and Sept; Fourth year 3 oz in March, April and 2 oz in May, Sept; and fifth year 3.5 oz in March, April, 3.0 in May and 2.0 in Sept. This is based on 15-5-10 formulation.

If you wanted to go organic they suggest Cottonseed meal applied at rate of 1 to 2 cups per plant in March and again in May.

Nitrogen does vary during the year and potash will vary somewhat. However, Phosphorous (the P in NPK) is stable and does not move much in the soil. Most gardens in south have too much P because they use to suggest 13-13-13. Over time it can get excessive. That should not be a problem with your situation however. It would be nice to know the NPK but in your situation the pH was much more important to know. It also varies during the year and over time.
It does look like the area you want to plant the blueberries should do well. Citrus will want a little higher pH.

So a regular balanced garden fertilizer like 888 or 141414 applied like you mention wouldn't be too bad? At that rate, the 'normal' nitrogen won't hurt the BBs? Is well aged chicken manure of any value for BBs?

Interesting no application during summer. I would have thought that's when most varieties need the most support as they're fruiting?

Citrus, I have lime I can add for pH. I could use the same balanced fertilizer for them?

I believe the theoretical NPK ratio for citrus is 5-1-3, but there aren't many fertilizers that have that exact ratio. I've used a 24-8-16 fertilizer with micronutrients that seems to work pretty well for my lemons, limes and mandarins.

The pH is perfect for blueberry. Low EC means the soil is low in salts. That's good and expected in well drained soil with high rainfall.

Nitrogen for blueberries should be in ammonia form not nitrate. It will tell you that on the bag, at least in USA. At that pH the perfect fertilizer for nitrogen needs of blueberry would be urea. An organic fertilizer will apply all needed nutrients. Well aged chicken manure should fit the bill just fine. Try that and if you don't get enough growth apply more or look for a fertilizer with ammonical nitrogen.

The mixed fertilizers are OK but most have nitrate nitrogen. Avoid those.

Fruitnut, to clarify, I can add the aged chicken manure liberally when I plant new BBs in that location, and that will provide everything needed? If I want more growth, I can then fool around with supplements like urea or appropriate chemical fertilizers. Can I add aged chicken manure as a top dressing fertilizer anytime to established plants?

I actualy planted a test SHB there with a shovel full of the chicken manure and another shovel of peatmoss. It really exploded and was looking great. So great it got stolen. The other 4 REs I planted there with only peatmoss and regular weak AmoniaNitrate feedings. I guess I can add some manure on top of them?

If really well aged the manure could be added to planting hole. That does have two potential issues: soil settling as the manure decomposes and salt damage to roots. I'd think more about using it as a top dressing or mulch around the plants after they get established.

How long does the nutrient giving effect of aged manure last? Does it wear out mid season? I've used it also with our other plants, but no idea about when and how much and if fancy chemical fertilizers are required. Amonia sulfate is my first time with non manure fertilizer.

Well, I put a shovelful around the large plants, proportionately less aroud smaller ones. No idea when to put more, or if I should cut back on the ammonia sulfate now.

I know organic crop producers just apply chicken litter once a year. It will continue to break down for up to three years. That does not mean that it will break down and provide as much nutrients in year two, but you should see some benefit. The nitrogen will be used up first. You probably should just put out the ammonia sulfate if the plants seem to slow down and show nitrogen deficiency. I would put out a low dose once a month if they were mine. Nitrogen tends to get used up or releases into the atmosphere, especially in high rainfall areas.

Thanks Gary, very helpful info.

I know ec in water from keeping freshwater stingrays is a measure of hardness .all of it calcium salinity nitrates biological waste.