Biochar Affected by Composting with Farmyard Manure. Issue 1 (1st January 2013)

• Record Type: Journal Article
• Authors: Prost, Katharina; Borchard, Nils; Siemens, Jan; Kautz, Timo; Séquaris, Jean‐Marie; Möller, Andreas; Amelung, Wulf
• Is Part Of: Journal of Environmental Quality. Volume 42:Issue 1(2013)
• Page Start: 164
• Page End: 172
• Publication Date: 2013-01-01
• Subjects: Agricultural ecology -- Periodicals; Environmental engineering -- Periodicals; Pollution -- Periodicals; 630
• DOI: 10.2134/jeq2012.0064
• Languages: English
• ISSNs: 0047-2425

Abstract

Abstract : Biochar applications to soils can improve soil fertility by increasing the soil's cation exchange capacity (CEC) and nutrient retention. Because biochar amendment may occur with the applications of organic fertilizers, we tested to which extent composting with farmyard manure increases CEC and nutrient content of charcoal and gasification coke. Both types of biochar absorbed leachate generated during the composting process. As a result, the moisture content of gasification coke increased from 0.02 to 0.94 g g −1, and that of charcoal increased from 0.03 to 0.52 g g −1 . With the leachate, the chars absorbed organic matter and nutrients, increasing contents of water‐extractable organic carbon (gasification coke: from 0.09 to 7.00 g kg −1 ; charcoal: from 0.03 to 3.52 g kg −1 ), total soluble nitrogen (gasification coke: from not detected to 705.5 mg kg −1 ; charcoal: from 3.2 to 377.2 mg kg −1 ), plant‐available phosphorus (gasification coke: from 351 to 635 mg kg −1 ; charcoal: from 44 to 190 mg kg −1 ), and plant‐available potassium (gasification coke: from 6.0 to 15.3 g kg −1 ; charcoal: from 0.6 to 8.5 g kg −1 ). The potential CEC increased from 22.4 to 88.6 mmolc kg −1 for the gasification coke and from 20.8 to 39.0 mmolc kg −1 for the charcoal. There were little if any changes in the contents and patterns of benzene polycarboxylic acids of the biochars, suggesting that degradation of black carbon during the composting process was negligible. The surface area of the biochars declined during the composting process due to the clogging of micropores by sorbed compost‐derived materials. Interactions with composting substrate thus enhance the nutrient loads but alter the surface properties of biochars.