Publications |
Sommer, R.; Vlek, P.L.G.; Sá, T.D. de A.; Vielhauer, K.; Coelho,
R. de F.R. and H. Fölster; 2004. Nutrient balance of shifting
cultivation by burning or mulching in the Eastern Amazon – evidence
for subsoil nutrient accumulation. Nutrient Cycling in Agroecosystems,
68: 257–271.
Sommer, R.; Fölster, H.; Vielhauer, K.; Maklouf Carvalho,
E.J. and P. L. G. Vlek; 2003. Deep soil water dynamics and depletion
by secondary vegetation in the eastern Amazon. Soil Sci. Soc. Am.
J., 67: 1672-1686.
Sommer, R.; Sa, T. D. de A.; Vielhauer, K.; de Araujo, A. C.; Fölster,
H. and P.L.G. Vlek; 2002. Transpiration and canopy conductance of
secondary vegetation in the Eastern Amazon. Agric. Forest Meteorol.,
112: 103-121.
Sommer, R.; Sá, T. D. de A.; Vielhauer, K.; Fölster,
H.; and P.L.G. Vlek; 2001. Water and nutrient balance under slash-and-burn
agriculture in the Eastern Amazon, Brazil - The role of a deep rooting
fallow vegetation. In: Horst W.J. et al. (eds.). Plant Nutrition.
Food security an sustainability of agro-ecosystems through basic
and applied research. Kluwer Academic Publisher. pp. 1014-1015.
Sommer, R.; Denich, M. and P.L.G. Vlek; 2000: Carbon storage and
root penetration in deep soils under small-farmer land-use systems
in the Eastern Amazon region, Brazil. Plant Soil, 219: 231-240.
Sommer, R.; White, J.W.; Wall, P.C. and K.D. Sayre; 2003. Model-based
assessment of maize cropping under conventional and zero-tillage
in highland Mexico – preliminary results. Poster presented
at the 2003 Annual Meetings of the ASA-CSSA-SSSA, Denver, Colorado,
USA, November 2–6. Annual Meetings Abstract CD.
|