Third year results, Fourth Corner Nurseries soil/biochar study

Erin Rasmussen

Third year results: Fourth Corner Nurseries Soil/Biochar Study
Richard Haard, Plant Propogationist, July 31, 2009

This study predates the coining of the term biochar and I claim grandfather rights to use the word charcoal.

Third year results, Fourth Corner Nurseries soil/biochar study

Summer 2009 Biochar plot studySummer 2009 Biochar plot studyresults are showing some trends I have had difficulty measuring with the last two years of cropping these plots. The use of buckwheat, a short season cover crop plant makes a visual view of performance reflecting nutrition, quite vivid. In spite of the dips in the plots due to deer browse.

This image is a merged sequence of pictures taken at same distance. Background may be confusing because of perspective. These plots are the first set, (south end), of treatments laid out in a systematic way. Results from the north set are similar and will be presented in a final poster

This plot study included: compost ( a wood based commercial compost of sewage solids)
charcoal 1 ( about 1/2 inch minus), charcoal 2 ( powder from John Flottvik's pyrolyser).
fertilizer: a complete, chemical fertilizer

These additives were only used once. In 2008 and 2007 all plots were given a light treatment of urea, none in 2009, although the early spring cover crop was legume.

Quirks shown in pictures: upper right dips in each of 3 plots due to deer browse. Bump in production in compost plot that is consistent with every year and a odd drop in plant height in fertilizer plus charcoal 2 plot. Also the soil analysis of the north set of plots is better than the south part, and this also shows in the charcoal 2 only plot at the north end of the south set.

This said there are some interesting trends showing in this third year of this experiment.

Compost is still showing benefit even after continuous cropping.

This year the strategy was to duplicate our farm soil management strategy of cover cropping after two years to build up organic matter and burn weed seed. First cover crop in March was vetch and fava bean. Buckwheat was planted immediately in May and will be tilled in within a few weeks to be replaced with another cover crop (oats or barley) before planting with transplanted native plants next spring.

The compost + charcoal and compost + fertilizer + charcoal plots are showing the best growth of all the plots. This to me is an indication of synergism or an additive effect of charcoal in combination with compost.

Fertilizer series. The first 2 years of cropping the benefit of fertilizer was shown. Now I am seeing a decline in production in these plots. The compost plus fertilizer plot mysteriously is not better than compost only.

Control set. Interesting that the growth in the charcoal 1 is less than the control. Perhaps indication the charcoal errr biochar is removing nutrients from the soil. As mentioned above charcoal 2 control set is in beginning of higher nutrition soil.

This image is original size that allows scrolling close up.
Here is an image that shows all plots full screen.

Rich Haard, Propagation Manager
Fourth Corner Nurseries
Bellingham, Washington