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I work to understand how deforestation for pasture and soybeans influences the biogeochemistry of Amazon soils. This work has shown, for example, that deforestation converts landscapes that behave as if they are nitrogen saturated to landscapes that emit much less nitrogen to the atmosphere as trace gases and leach less nitrogen to streams.
Today, one important use for older and degraded pastures is increasingly intensive management, especially planting of soybeans. I investigate the effects of intensification of pasture agriculture and the expansion of soybean agriculture. My colleagues and I measure changes to the dynamics of soil carbon, nitrogen and phosphorus. For example in soybean field, we try to understand the fate of phosphorus applied as fertilizer and the nitrogen fixed by soybeans. We also measure changes to soil physical properties, such as hydraulic conductivity that control the generation of surface runoff.
Rafael Scheffler, Shelby Hayhoe-Riskin, Frank Base, Michela Figueira, Stephen Porder, Jerry Melillo, Carlos C. Cerri, Paul Steudler, Carlos C.P. Cerri, Marisa C. Piccolo, Janaína Braga do Carmo
In press. Riskin, S. H., S. Porder, C. Neill, A. M. Figueira, C. Tubbesing, and N. Mahowald. The fate of phosphorus fertilizer along a chronosequence of soy fields on the Amazonian agricultural frontier. Philosophical Transactions of the Royal Society B.
2013. Riskin, S.H., S, Porder, M. E. Schipanski, E. M. Bennett, and C. Neill. Regional Differences in Phosphorus Budgets in Intensive Soybean Agriculture. BioScience 63: 49–54.BioScience.
2012. Baese, F., H. Elsenbeer, C. Neill and A. V. Krusche. Differences in throughfall and net precipitation between soybean and transitional tropical forest in the southern Amazon, Brazil. Agriculture, Ecosystems and Environment 159: 19-28.
2011. Scheffler, R., C. Neill, A. V. Krusche and H. Elsenbeer. Soil hydraulic responses to land-use change associated with the recent soybean expansion at the Amazon cropland frontier. Agriculture, Ecosystems and Environment 144: 281–289.
2010. Cleveland, C.C., B.Z. Houlton, C. Neill, S.C. Reed, A.R. Townsend and Y. Wang. Using indirect methods to constrain symbiotic nitrogen fixation rates: A case study from an Amazonian rain forest. Biogeochemistry 99:1-13.
2010. Germer, S., C. Neill, A.V. Krusche and H. Elsenbeer. Influence of land-use change on near-surface hydrological processes: Undisturbed forest to pasture. Journal of Hydrology 380:473-480.
2008. Davidson, E.A., G.P. Asner, T. Stone, C. Neill and R.O. Figueiredo. Objective indicators of pasture degradation from spectral mixture analysis of Landsat imagery. Journal of Geophysical Research 113: G00B03, doi:10.1029/2007JG000622.
2007. Piccolo, M.C. and C. Neill. Mineralização e nitrificação do nitrogênio do solo sob floresta e pastagem na amazônia brasileira. Pages 581-634 in T. Yamada, S.R. Stipp and A.G.C. Vitte (eds.), Nitrogênio e enxofre na agricultura Brasileira. International Plant Nutrition Institute, Piracicaba, SP, Brazil.
2006. Neill, C., M.C. Piccolo, C.C. Cerri, P.A. Steudler and J.M. Melillo. Soil solution and nitrogen oxide losses during clearing of lowland Amazon forest for cattle pasture. Plant and Soil 281: 233-245.
2005. do Carmo, J. B., C. Neill, D. C. Garcia-Montiel, M. C. Piccol.o, C. C. Cerri, P. A. Steudler, C. A. Andrade, C. C. Passianoto, B. J. Feigl and J. M. Melillo. Nitrogen dynamics during till and no-till pasture reformation sequences in Rondônia, Brazil. Nutrient Cycling in Agroecosystems 71:213-225.
2005. Neill, C., P.A. Steudler, D.C. Garcia-Montiel, J.M. Melillo, B.J. Feigl, M.C. Piccolo, C.C. Cerri. Rates and controls of nitrous oxide and nitric oxide emissions following conversion of forest to pasture in Rondônia. Nutrient Cycling in Agroecosystems 71:1-15.