Phosphorus Speciation in Manure and Manure-Amended Soils Using XANES Spectroscopy
S. Sato, D. Solomon, C. Hyland, Q.M. Ketterings, and J. Lehmann, NSLS Science Highlights, February 9, 2006

Department of Crop and Soil Sciences, Cornell University, Ithaca, NY
It is important to know what inorganic phosphorus (P) species are being formed in soils subjected to high, long-term poultry-manure application in order to understand P accumulation and release patterns. Phosphorus K-edge XANES spectra of fresh manure showed no evidence of crystalline P minerals, but did exhibit a dominance of soluble calcium phosphates (CaP) and free and weakly bound phosphates. Soils with a short-term manure history contained both Fe-associated phosphates and soluble CaP. Long-term application resulted in a dominance of CaP and a transformation from soluble to more stable CaP species. However, none of the amended soils showed the presence of crystalline CaP. Maintaining a high pH is therefore an important strategy that can be used to minimize P leaching in these soils.

Mycorrhizal responses to biochar in soil – concepts and mechanisms
Daniel D. Warnock, Johannes Lehmann, Thomas W. Kuyper and Matthias C. Rillig, Plant and Soil, Volume 300, Numbers 1-2 / November, 2007
Abstract
Experiments suggest that biomass-derived black carbon (biochar) affects microbial populations and soil biogeochemistry. Both biochar and mycorrhizal associations, ubiquitous symbioses in terrestrial ecosystems, are potentially important in various ecosystem services provided by soils, contributing to sustainable plant production, ecosystem restoration, and soil carbon sequestration and hence mitigation of global climate change. As both biochar and mycorrhizal associations are subject to management, understanding and exploiting interactions between them could be advantageous. Here we focus on biochar effects on mycorrhizal associations. After reviewing the experimental evidence for such effects, we critically examine hypotheses pertaining to four mechanisms by which biochar could influence mycorrhizal abundance and/or functioning. These mechanisms are (in decreasing order of currently available evidence supporting them): (a) alteration of soil physico-chemical properties; (b) indirect effects on mycorrhizae through effects on other soil microbes; (c) plant–fungus signaling interference and detoxification of allelochemicals on biochar; and (d) provision of refugia from fungal grazers. We provide a roadmap for research aimed at testing these mechanistic hypotheses.
Keywords Biochar - Arbuscular mycorrhiza - Ectomycorrhiza - Carbon storage - Restoration - Terra preta

Bio-energy in the Black
Johannes Lehmann, Frontiers in Ecology and the Environment, 2007

Simpler Way To Counter Global Warming Explained: Lock Up Carbon In Soil And Use Bioenergy Exhaust Gases For Energy
Science Daily News, May 12, 2007

Writing in the journal Nature, a Cornell biogeochemist describes an economical and efficient way to help offset global warming: Pull carbon dioxide out of the atmosphere by charring, or partially burning, trees, grasses or crop residues without the use of oxygen.

Commentary: A Handful of Carbon
Johannes Lehmann in Nature Magazine, Vol 447, 10 May 2007

Locking carbon up in soil makes more sense than storing it in plants and trees that eventually decompose, argues Johannes Lehmann. Can this idea work on a large scale?

Charcoal as Soil Conditioner: Studies in the humid Tropics
Christoph Steiner1, W. G. Teixeira2, J. Lehmann3and W. Zech1, U Georgia TP 2004

Cornell University: Bio-Char Projects 2007

Bio-char Projects

Currently (January 2007) we conduct experiments to evaluate the effects of bio-char on nutrient adsorption, nutrient leaching, water percolation, soil water availability and carbon cycling as well as the stability and mobility of bio-char itself with research in our Ithaca lab, in Colombia, Brazil, Zambia and Kenya.

Long term Effects of manure, charcoal and mineral fertilization on crop production and fertility on a highly weathered Central Amazonian upland soil January 2007
Christoph Steiner · Wenceslau G. Teixeira · Johannes Lehmann ·Thomas Nehls · Jeferson Luis Vasconcelos de Macêdo · Winfried E. H. Blum · Wolfgang Zech

Abstract