A Review of Biochar and Soil Nitrogen Dynamics

来自 mdpi.com

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734

作者：

T Clough，L Condron，C Kammann，C Müller

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摘要：

Interest in biochar stems from its potential agronomic benefits and carbon sequestration ability. Biochar application alters soil nitrogen (N) dynamics. This review establishes emerging trends and gaps in biochar-N research. Biochar adsorption of NO3, up to 0.6 mg g1 biochar, occurs at pyrolysis temperatures 600 °C with amounts adsorbed dependent on feedstock and NO3 concentration. Biochar NH4+ adsorption depends on feedstock, but no pyrolysis temperature trend is apparent. Long-term practical effectiveness of inorganic-N adsorption, as a NO3 leaching mitigation option, requires further study. Biochar adsorption of ammonia (NH3) decreases NH3 and NO3 losses during composting and after manure applications, and offers a mechanism for developing slow release fertilisers. Reductions in NH3 loss vary with N source and biochar characteristics. Manure derived biochars have a role as N fertilizers. Increasing pyrolysis temperatures, during biochar manufacture from manures and biosolids, results in biochars with decreasing hydrolysable organic N and increasing aromatic and heterocyclic structures. The short- and long-term implications of biochar on N immobilisation and mineralization are specific to individual soil-biochar combinations and further systematic studies are required to predict agronomic and N cycling responses. Most nitrous oxide (N2O) studies measuring nitrous oxide (N2O) were short-term in nature and found emission reductions, but long-term studies are lacking, as is mechanistic understanding of reductions. Stable N isotopes have a role in elucidating biochar-N-soil dynamics. There remains a dearth of information regarding effects of biochar and soil biota on N cycling. Biochar has potential within agroecosystems to be an N input, and a mitigation agent for environmentally detrimental N losses. Future research needs to systematically understand biochar-N interactions over the long term.

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关键词：

biochar immobilization mineralization nitrate leaching nitrogen nitrous oxide ammonia volatilisation

DOI：

10.3390/agronomy3020275

被引量：

430

年份：

2013