The potential contributions of exogenous organic matters (EOMs) to soil C and mineral N supply depend on their mineralization, which can be assessed in laboratory incubations. Such incubations are essential calibrate decomposition models, because not all EOMs tested the field. However, EOM resource-intensive. Therefore, easily measurable characteristics that useful predict behaviour needed. We ...

Numerous principles for the mineralization of samples and for the measurement of the elements have been tried since the days of Liebig, Dumas, Dennstedt and Pregl. Attempts to develop accurate and reliable ultramicro methods have been successful only in recent years. Almost absolutely quantitative recovery of the analyte from the mineralization process, freedom from risk of contamination, and v...

J. M. H. Knops,* K. L. Bradley and D. A. Wedin School of Biological Sciences, School of Natural Resource Sciences, University of Nebraska, 348 Manter Hall, Lincoln, NE 68588, USA. *Correspondence: E-mail: [email protected] Abstract Plant species are hypothesized to impact ecosystem nitrogen cycling in two distinctly different ways. First, differences in nitrogen use efficiency can lead to positiv...

Most evapotranspiration over land occurs through vegetation. The fraction of net radiation balanced by evapotranspiration depends on stomatal controls. Stomates transpire water for the leaf to assimilate carbon, depending on the canopy carbon demand, and on root uptake, if it is limiting. Canopy carbon demand in turn depends on the balancing between visible photon-driven and enzyme-driven steps...

Remote sensing studies suggest that savannahs are transforming into more tree-dominated states; however, progressive nitrogen limitation could potentially retard this putatively CO2-driven invasion. We analysed controls on nitrogen mineralization rates in savannah by manipulating rainfall and the cover of grass and tree elements against the backdrop of the seasonal temperature and rainfall vari...

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The measurement of soil carbon dioxide (CO2) respiration is a means to gauge biological soil fertility. Test methods for respiration employed in the laboratory vary somewhat, and to date the equipment and labor required have limited more widespread adoption of such methodologies. A new method to measure soil respiration was tested along with the traditional alkali trap and titration method. The...