Hi! I guess there are as many ways to grow weed as there are growers. From my experiences its best to keep it simple and not overcomplicate things. keeping in mind that these are some tough plants, you really dont need to cradle them. I am always amazed just how tough this plants are. All kinds of nasty shit has happened to my babies, and not only did they survived, they thrived. Snails have defoliated them - completley, and they bounced back stronger then ever, stroms have broken them and they just keep on groving, they overpower and sufficate any other weeds growing nearby, I myself, by beeing clumsy, have broken young plants when transporting them to their outdoor homes, and I mean comletly broken them in two, then I just put them back together, make a brace out of twigs and tie it up with some string... they just keep on growing like nothing happened, and one such plant just happened to become one of the heaviest yielders Ive ever got, just shy of two pounds of bud on that baby.
So my point is... keep it simple.. or not, its your choice.
So with that spirit in minde I never haull in soil or watter, I am way to lazy to burden myself like that. I amende the soil that is already there, but only when I think its necessary, a lot of the times there is no need as the natural soil in the area is excellent. If not, for fertilization I add dehydrated manure in pellet form, I also check the ph and add if necessary lime or peatmoss, If its very heavey clay like soil I mix in coco fibres, or just dried up plant matter, like leaves and twigs that are laying around, to loseen it up, for dry soils I also use coco fibres with polymer crystals. In flower time I will also add cemichal fertilizers, if I see the need for it.
As for pathogenes... They are always gonna be present in the outdoor inviroment, no matter what you do. In my minde its not my objective to conform the enviroment to my plants, rather the other way around, to grow healthy plants that are adapted to the enviroment and can resist the pathogens. Otherwise you have to grow in a bubble, and theres just no way of doing that growing guerilla, or just outdoors for that matter. Control is an illusion.
So my style of growing weed could be called the lazy mens method. I prepare the sites ussually in early winter, then come spring I plant and pretty much forget... till september. I leave my plants to their own devices and in most cases they do just fine. All in all I visit my sites only 3 to max.5 times per season and that includes planting and harvesting. The number depends on whether Im using female clones or regular seedlings. In some cases there has to be more visits if height of the plants posess a security issue, as some of my plants are right under people noses, such sites I visit only at night.
In regards to yields, they are not huge (on avarage 7ounces per plant), but I plant the numbers to make up for that. The yield in my opinion is just as much tied to the genetics as it is to the enviroment, if not more so. I have never bought seeds, the prices are just ridicules, even the cheap ones. For over a decade now I have been growing plants that originated from bag seeds, and have been making my own seeds ever since. So I dont now the genetic background or thc levels, but I can distinguishe three phenotyps that I get regurarly from these seeds. They are mostly leaning on the sativa side, with huge long and airy buds, never had any mold problems, they finish early, end of september for the most part and the smoke is potent giving you a sativa high with one pheno being extremly strong with a trippy kind of effects. So Im more then happy with that.
Well, thats my 2c, and however you choose to go about it, I wish you much success. And keep in mind that advices are fine but there is nothing like learning from your own experiences.