Open Access‘Bioenergy from cattle manure? I mplications of anaerobic digestion and subsequent pyrolysis for carbon and nitrogen dynamics in soil’
Author(s) -
Schouten Socrates,
van Groenigen Jan W.,
Oenema Oene,
Cayuela Maria L.
Publication year - 2012
Publication title -
gcb bioenergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.378
H-Index - 63
eISSN - 1757-1707
pISSN - 1757-1693
DOI - 10.1111/j.1757-1707.2012.01163.x
Subject(s) - biochar , digestate , manure , agronomy , bioenergy , anaerobic digestion , mineralization (soil science) , soil carbon , environmental science , soil water , chemistry , soil fertility , biofuel , environmental chemistry , pyrolysis , methane , waste management , soil science , biology , organic chemistry , engineering
Abstract Cattle manure can be processed to produce bioenergy, resulting in by‐products with different physicochemical characteristics. To evaluate whether application of such bioenergy by‐products to soils would be beneficial compared with their unprocessed counterpart, we quantified differences in greenhouse gas emissions and carbon ( C ) and nitrogen ( N ) dynamics in soil. Three by‐products ( 15 N ‐labeled cattle manure, from which anaerobic digestate was obtained, which was subsequently pyrolysed) were applied to a loess and a sandy soil in a laboratory incubation study. The highest losses of soil C from biological activity ( CO 2 respiration) were observed in manure treatments (39% and 32% for loess and sandy soil), followed by digestate (31% and and 18%), and biochar (15% and and 7%). Emissions of nitrous oxide ( N 2 O ) ranged from 0.6% of applied N from biochar to 4.0% from manure. Isotope labeling indicated that manure N was most readily mineralized, contributing 50% to soil inorganic N . The anaerobic digestate was the only by‐product increasing the mineral N pool, while reducing emissions of N 2 O compared with manure. In biochar treatments, less than 18.3% of soil mineral N derived from the biochar, while it did not constrain mineralization of native soil N . By‐products of anaerobic digestion and pyrolysis revealed soil fertility in addition to environmental benefits. However, the reported advantages lessen when the declining yields of C and N over the bioenergy chain are considered.