I tried soybean meal which would be similar. It formed a sticky film on the soil surface as the bacteria broke it down. I grew up on a hog farm so whey and sticky mess fit right in. But I didn't like the fungus gnats that seemed to explode in numbers in blueberry pots after application. I'm going back to ammonium sulfate, 21-0-0. It will burn the plants if you apply too much at once but it works.

Thanks for quick response. What are fungus gnats? They sound pretty gross. Do they eat the fruit and/or bush or just fly around and annoy? Where do you get ammonium sulfate, at the garden centers? My plant (bush) is not growing as good as it should and I want more fruit on it. Not sure what to use? Thanks.

Some claim fungus gnats attack the roots especially fig growers. But I think a lot of that is an excuse for failed rooting.

The controlled release fertilizers are another option. I just order some linked below. These won't burn the plant like 21-0-0 can.

Here is a link that might be useful: bb fert