If you’ve been following this blog you may have noticed my struggle with soil fertility. The first few years of the garden were prolific. I started with a yard that had been growing grass quite successfully for untold number of years. I composted/removed the sod and mixed in topsoil and compost. In the intervening years I have amended my soil with cover crops, homegrown compost, commercial compost, and feather meal.
Most gardening books say to generously apply compost, amend pH, and all will be well. Still, most of my plants have shown a gradual decline in size and productivity over the years.
This winter, a climbing buddy reminded me of Steve Solomon and his book Growing Vegetables West of the Cascades. VERY IMPORTANTLY, Steve writes about the special challenges our soils face for growing veggies. In general, our native soils are impoverished in P, leached of Ca by our abundant winter rainfall, but high in K. My own soil tests have repeatedly shown low N, high P, and very high K with a moderate pH. These home tests do not measure other important nutrients like Ca, Mg, or the even more ‘trace’ essentials like S, Fe, Cu, Zn, Mn, B.
So this year I am trying Steve Solomon’s ‘Complete Organic Fertilizer’ (COF). Variations allow for adding different elements from different sources, but here is what I did (per 100 sqft):
N: 3 QT soybean seed meal + 1 QT feather meal
Ca: 1 PT agricultural lime (x2 for first few years)
Mg: 1 PT agricultural gypsum
P: 1 QT bonemeal
B: 2 t laundry Borax
Zn: 1.5 t ZnSO4
Cu: 1 t CuSO4
Mn: 1 PT kelp meal
Hopefully this combo, with some home compost, will do the trick! I am putting in a full batch of COF prior to planting, adding a small amount in transplant holes, and will side-dress hungry crops through the season.