we have done tests on different varieties of barley and harrington 2 row is always the winner . anything we have tried with 6 row barley has ended up less than impressive. we found 6 row to have way higher protein and less starch ,,,,great feed barley but not so great for mashing . the type of soil its grown on and the weather conditions have a large influence on the grain . a good year seems to grow good barley that has 10 percent or hopefully less small starch granules in the kernel thus dropping the gel temp significantly .
silk city as far as nutrients go we have never tried that you may be onto some thing , possibly the yeast trub from the previous batch would work . guess we need to do an experiment .
tim