Alice and I were at the second day of the PFI cooperator's meeting today, talking with other farmers and Practical Farmer's staff about last year's research and planning the research and demonstration projects people will be doing next year. PFI are pretty cool for a lot of reasons, and one of them is they organize and sponsor a bunch of research:

Here's a page with all the horticulture research projects from last year,

Here's a page you can get to all of their research projects and other resources,

and I was going to put a link through to our results from the research we and Scattergood friend's school farm did, but it isn't up yet. In short, the variation in sweet potato yields, from plant to plant and from row to row is really high, so the main question of our research, "Does removing ancillary roots from sweet potato vines increase yields of the harvested roots?" couldn't adequately be answered, since our interval of possible effects was quite large: we were 95% confident that removing the roots not coming from the crowns of sweet potato plants caused something between a 39% decrease and 56% increase in yield. Which doesn't say much, other than that sweet potato research is difficult at our scale.