Lettuce Seedling Trials
with assorted Biochars & Fertilizers
Second, Third, Fourth
The first lettuce seedling trial began on June 23, and used a blend of 1-year-old composted chicken manure and a high-carbon fly ash "biochar" from NH (60% carbon). This trial was unplanned and spontaneous, arising from a need to test this new "biochar" for its effects on soil and plants prior to a decision to acquire a large quantity.
I mixed composted chicken manure with NH "biochar" blended at 4-to-1 and 8-to-1 ratios, and filled half of two Accelerator trays. The NH "biochar" has lots of alkali minerals from wood ashes, and thus has an extremely high pH—11.0 to 12.0. So, I hoped compost acids will balance and neutralize this harsh extreme. As an afterthought, I made a third tray with only compost as a control.
Then Saratoga Apple owner Nate Darrow chided me for not including any soil in the mixes for my trial trays, so I blended field soil equally with compost as a second control. While I dug more chicken compost, I snapped a fetching photo of Joseph from Jamaica, Nate's foreman, who led a crew excavating the opposite side of the pile to spread on vegetable fields.
With two fingers, I pinched 3 to 5 seeds into each Accelerator cell, nestled the trays in straw mulch in a greenhouse bed, watered them, and left for my own house. Three weeks later, I returned with little anticipation of significant results from this impromptu test of an odd material from NH. No one thinned the sprouts to a single seedling per cell, so lettuce was crowded densely in the trays. What I saw caught me by complete surprise, astonished me—and demanded replication.
Below is my final photo of the first trial, taken July 14:
Both soil blends with biochar grew better than chicken manure compost only, or 50/50 soil & compost. The 50/50 soil blend actually did poorly, with weak, irregular growth. Compost alone yielded satisfactory vigorous growth. But the 4:1 biochar blend grew slightly better—more than is obvious in the photo.
But the 8:1 biochar blend erupted like a green volcano, even though seedlings were squeezed tightly in Accelerator cells. They were nearly twice the size of the 4:1 and compost only cells. Astonished, I contemplated how much profit Nate Darrow can recover if he can sustain this rapid growth while he rotates seedlings into Accelerator cells, out into greenhouse beds, then off to market.
Yet, I was puzzled. The NH "biochar" is uninoculated, nor is it mineralized, and is only a scant 10% of my soil blend. Yet, in only three weeks, raw, fresh biochar had kicked lettuce into high gear, yielding the outburst of optimum growth. Pondering this, I concluded that soluble minerals are liberated from woodchip fly ash, and thus deliver a biologically balanced blend of major minerals and trace elements to seedlings. Thus, perhaps the eruption of green growth wasn't due to char, but fly ash.
This initial trial turned up such dramatic effects and unexpected results, I started a second trial in early August to investigate these effects further.