New Cambodia study shows positive results for biochar in vegetable growing trial

Effect of different levels of biochar on the yield and nutritive value of Celery cabbage (Brassica chinensis var), Chinese cabbage (Brassica pekinensis), Mustard green (Brassica juncea) and Water spinach (Ipomoea aquatica)
Chhay Ty, Vor Sina, Khieu Borin and T R Preston*

Center for Livestock and Agriculture Development. Pras Teat village, Rolous Commune, Kandal Stung district, Kandal province.
PO Box 2423 Phnom Penh 3, Cambodia
chhayty@celagrid.org
* Finca Ecológica, TOSOLY, AA #48, Socorro, Santander, Colombia
Abstract
"The experimental design in a field plot trial (soil pH 5.8; OM 17%) conducted in the rainy season (September to October 2012) involved 24 treatments arranged in a 6*4 factorial arrangement with 3 replications. The first factor was level of biochar (0, 1, 2, 3, 4 and 5 kg/m2); the second factor was the type of vegetable (Water spinach, Chinese cabbage, Celery cabbage and Mustard green). Fertilization was with biodigester effluent (10kg N/ha applied to all treatments. The area of each plot was 1.6m2 (2.0m length x 0.8m width) with spacing between each plot of 0.5m. The experiment lasted 35 days. The biochar (pH 9.3; OM 29.4% in DM) was from a paddy rice drier (combustion temperature with rice husks as feedstock was about 500°C).

Increasing the application of biochar from 0 to 5 kg/m2 led to linear increases in biomass DM yield of 39, 100, 300 and 350 % for Water spinach, Chinese cabbage, Celery cabbage and Mustard green, respectively. Soil quality was improved after the 35 day trial (pH 6.82-7.13; OM 22.6 - 25.7%). The chemical composition of the biomass DM showed average increases in crude protein from 13.7 to 18.1% for leaves and from 7.23 to 9.16 for stems. By contrast, crude fiber in leaves decreased from 14.5 to 9.27% in DM while in stems it fell from 15.6 to 10.7%."
http://www.lrrd.org/public-lrrd/proofs/lrrd2501/chha25008.htm