work in some beneficial fungus and the fertilizer needs will be reduced. the fungi will free up a lot more nutrients and make them available to the plants. plant some nitrogen fixers with them (you've got the trellis already, grow some peas!) that you have inoculated with the correct bacteria and the soil will fertilize itself over the years with generous top dressing in spring and fall
Wanna dumb that down a little for me?
sure. Well I'll try anyway.
In a healthy balanced system insects, bacteria, and even more so, fungus break down dead organic matter and make the nutrients held in them available again for new plant life. There are some really good products available from Paul Stamets that are designed to introduce lots of fungus to the soil in your garden to help make these nutrients available so as long as you have plenty of available organic matter (compost) given time, air, and moisture, the fungi will make most of the nutrients your hops need available to them with out needing to add a lot of concentrated macro nutrients (fertilizer).
However the main macro nutrient that we as 'farmers' like our plants to have a lot of is nitrogen because it helps the plants get really big really fast. miracle grow has lots of inorganic nitrogen which is highly available so plants get big fast. 'Organic' fertilizers like fish emulsion do the same thing to a lesser. The problem there is that you are trapped in the cycle of feeding that way. the plants grow so fast that they start to use up all the other macro and micro nutrients in the soil and because you are of course carefully preventing mold and bugs and 'weeds' from encroaching on your garden very little of this is getting replaced through the normal pathways of nature. so you end up with soil that gets poorer and poorer until, without your inputs, it is totally dead and unable to support life.
Legumes, or more specifically species of bacteria that co-habitat with legumes and some other plants, have the unusual habit of taking nitrogen out of the air and 'fixing' it in the soil in little nodules which is good because the process of decomposition ties up nitrogen and can cause some loss of available nutrient as the dead organic matter is decomposed into soil.
Enter the fungi which will grow mycilium (the whitish fuzzy mold like part of a mushroom that grows in the substrate) around the roots of your plants. These mycilium take the larger compounds which are difficult for your plants to absorb, break them down into smaller pieces and use some of it. other parts that the fungi don't really need anyway are passed through to the roots of the plants. In return the plants will share some of their moisture and carbohydrates with the fungi.
you won't get quite the same level of rapid growth and huge yields you might get with a concentrated chemical fertilizer application but then, as Denny is fond of pointing out, after a few years you are likely to get more hops than you can use anyway. This way you don't have to wear protective clothes to care for your plants and if you forget to feed or water for a couple weeks they are more likely to survive on their own.
it's pretty hippie dippy and touchy feely but it works.
Check out this site. I am in no way affiliated with this company. I have used their grow your own edible mushroom kits and that's fun. But I've seen Paul Stamets talk and he's got some very very cool ideas.
http://www.fungi.com/I apologize for any scientific simplifications of errors I might have made in the above post. It was some what off the top of my head.