I have been adding composted breeder house chicken manure for 2-3 years to a few fields. Each field is about 1 acre in size. One field (I'll call it field A) has had manure, ash, biochar added to it for 3 years now. My other 2 fields ( I'll call them fields B&C) have only had manure, ash and biochar added for 2 years. I knew that the nitrogen in my manure is only 35-45 lbs per ton of manure but only 12-15 lbs of that nitrogen is plant available. The rest isn't broken down/available till 2-3 years. I actually put 5 tons to the acre so I'm actually getting 175-225 lbs of total nitrogen w/ 60-75 lbs that's plant available and another 60 lbs for each previous year(s) up to 3 years max. The thing I noticed is that the longer I do this yearly the additive effect is greatly helping. Besides the 60-75 lbs of nitrogen this year by putting 5 tons per acre I can actually see both physical and chemical differences between when I first started and between field A vs B and C. When I first started my soil had a pH around 5.3-5.6 . It also was classified as medium to low in NPK and micronutrients. It was sandy and was light brown to light orangish (we also have red clay here) in color. Now fields B & C are medium to dark brown and more loamy with nutrients all in high range except K-potash Wich is in the upper medium range. While field A is dark brown, even more loamy and is classified as very high in nutrients. Field A has approximately 180 lbs of nitrogen that's plant available as every year I add manure you also need to add previous years to the total (remember 1/3 is available per year for 3 years) so in fields B & C it's only 120 lbs of plant available nitrogen because it only has this year's plus last year's vs A having manure for 3 years on it. Seeing results this dramatic was astounding as our local county extension office rep didn't think organic would do well or be cost effective. He said adding tons of lime and hundreds of pounds of chemical fertilizers would have cost less and done better. By my calculations it would have cost about $750-1000 per acre to do it his way. This would have cost a total of $3000 first year and about $1500 for years not needing lime. I only pay $500 for almost 30 tons of manure (that's enough for all 3 fields and test gardens and even worm compost beds. I never added lime, my ash and biochar I make from trees I'm clearing from crop land and storm damaged trees in my woodlands. My soil tests also showed my pH in field A is 6.6 and fields B&C's pH is 6.0 . Now I know not everyone has a neighbor that has breeder type chicken house's and from what I have heard about broiler chicken house manure having reduced ammonia to lower bird fatalities (Wich basically eliminated nitrogen in its manure) it may cost larger growers more to grow organically BUT I have shown with some research, time and knowledge growing organically can be cheaper, way better to the soil, to earth, for our health and even spiritually. I haven't had only success, I've also had failures too, so just realize that learning from failures can actually be beneficial. I have some test gardens to try new plants, methods (such as intensive planting/spacing) etc. so that even if I do fail it's not on acre scale. Some plants do well here but might not where you are and vice a versea. Also remember that one man's trash is potentially our black gold (soil) so always be looking for things others may be throwing out, rotten food, feed, seed can be composted. People who mow grass may give you tons of organic matter, tree trimmers might have tons of mulch etc. Anyone housing animals usually are glad to get rid of tons of soiled bedding and piles of manure. Just do research as some manure are not useful (example is horse manure that the horses ate grass that had herbicides used on them as this will kill vegetables just like the weeds in the pasture grass it was originally used in). So think organic but also ask the right questions besides just can I haul it off.
I grow small gardens for personal food, flowers to sell, I also grow in acre fields to sell vegetables at local farmers market, New Orleans to Mobile and up to Laurel MS. I'm near Hattiesburg MS so they all are at most an hour's drive. I'm known as the Italian/Cajun farmer as mostly what I sell is directed twords that. I also sell prepared food like sauce, chicken parmesan, gumbo, red beans n rice.... ATM I have seedlings of German Johnson (a better version of pink Brandywine) old German (a yellow beefsteak type) Marion (red beefsteak) Cherokee purple, Amish paste about to be transplanted in field A with some peppers pepperoccini, Tabasco, Cayenne and other hot peppers. In field B I'll plant half acre of Clemson spineless and other half acre in burgundy okra. Field C is in legumes all year with clover and red beans when clover sets seed soon (fixation white clover). I also have garlic, onions, basil, and other herbs in smaller gardens as I'm atm not testing things so they were open.
Companion Planting Guide by World Permaculture Association