your going to plow a 100 square foot area? im sure those numbers would be less for marijuana growing, mainly because rather than plow through a 10 by 10 foot area and mix the ferts evenly we dig 2 foot wide by 3 foot deep holes and mix a proportionally smaller amount into the soil and fill in the hole, though depending on the quality of the soil you may not want to add any ferts, if it's a clay like soil you will want to add a fluffer like vermiculite, if it's a sandy soil something like peat will be useful to hold moisture and nutrients. dolomite lime is always a good thing too add...you don't want to burn your plants or mess up the ph with too many amendments, and honesly blood and bone meal is nasty strong stuff, you will want to add it to your soil WEEKS before you put your plants in because it will need to rot and decompose first, the smell is terrible and attracts animals that could dig up your plants looking for raw meat if you don't' wait. if you were to add them also, you wouldn't need much els, i'm sure not everybody agrees with me but with guerrilla growing especially less is more, if you over do it you will end up with burnt and dying plants(seedlings can take very little ferts)better to underdo it in my opinion and feed later on when they are bigger and can handle it, or when they show that they need nitrogen. also, you will want to stop giving it nitrogen near the end of budding to allow your leaves to drain of chlorophyll and make your buds taste better, if you give too much nitrogen to the soil you wouldn't be able to do that, you bud would still be just fine, but it's just another point for my "less is more" take on growing.
