Here are a couple subjects I found that are seldom discussed in articles and forums. I think they can impact your success growing hops.
Poor subsoil conditions. Have you done a compaction/perk test? Take a shovel or a post hole digger and walk your site. Dig or auger a series of holes a minimum of 2 feet deep across the site. Check for orange iron banding in the soil which could indicate a seasonally high water table. Do the holes fill up with water? If they do, you may have to install drain tile or sockpipe. Also, note any "hardpan" - soil layers that are so compacted that roots can't penetrate. (If you have difficulty digging through the soil, imagine a plant trying to put a root down into it.) Hardpan is really common in agricultural land that has been field-cropped with tractors for many years.
Lynn, the head hop grower at Great Lakes Hops has over 30 years of experience in the horticultural field. Browse the blog articles here to find useful growing information for humulus lupulus, based on personal experience and observations at Great Lakes Hops.