Water Extract from Straw Biochar Used for Plant Growth Promotion: An Initial Test

Abstract

The production of energy and biochar from the pyrolysis of straw and other agricultural residues is a developing industry that holds the potential to reduce air pollution from in-field burning, recycle nutrients, reduce chemical fertilizer inputs, and improve soil quality. Use of biochar in agriculture is undergoing tests globally. Water-soluble organic compounds from pyrolysis residue containing humic substances, low-molecular weight acids, and neutral compounds and inorganic elements containing macro and micro nutrients have been shown to be beneficial for plant growth. In the present study, crop straw biochars were extracted into hot water and the extracts tested for their effect on growth of Chinese cabbage. The extracts were sprayed 10 times at three different dilutions throughout the growing period. The extracts were characterized for inorganic elements by ICP-MS and for organic compound type by LC-OCD and FTIR. Results showed that extracts of both wheat and maize straw biochar can significantly increase the yield, vitamin C content, and soluble protein content while decreasing the nitrate content of the cabbage at dilutions of 50 or 100 times. Water extract from biochar was found to have great potential as a liquid amendment in agricultural.

Keywords

• Biochar
• Yield
• Quality
• Water extractable organic carbon
• Chinese cabbage
• Humic substance