Many fruits LOVE magnesium and the berries are one that does according to the amish, even the poorest of amish will put epsoms salts around their berry patches and people often use it in their vegetable gardens....They say it makes the berries taste sweeter....
I have installed sprayer irrigation on a 5 acrea field that will be working full time next year and made it so I can use 1 or all 7 sprayers...so I can spray grass seed, minerals, epsoms salts, etc. out of 1 or all of these huge sprayers and experiment by seeing how fast the hay grows, what color it turns and how much the cows love it or don't love it.....and the black berries are under the same sprayers as are the chickens, so the chickens can have a shower with epsoms salts rain..