♦ Characterization of water quality in the micro watershed of the river Sane, SE Mexico; Conacyt, Mexico.

   2007-2009

♦ Soil and water management in Tabasco, Mexico;  SEDAFOP, Tabasco. 2002-2003

♦ Soil fertility and soil erosion in different regions of Tabasco, Mexico; Fundación Produce, Tabasco. 2002

♦ Influence of soil mesofauna on the gas production of strongly acidic forest soils; Forstliche Lehr- und

   Versuchsanstalt Freiburg, Germany . 2002

♦ Soil degradation in West Africa, part of an interdisciplinary project (IMPETUS) of the universities Köln and

   Bonn, Germany. 2001-2003

♦ Revision of the German soil classification system (Bodenkundlichen Kartieranleitung), 5. edition (KA5);  AG

   Boden, Hannover, Germany. 2001

♦ Study about the BSE-disease; Fördergemeinschaft für Nachhaltige  Landwirtschaft e. V., Bonn Germany.

   2000-2001

♦ Soil biological parameters in different forest stands in Northrhine-Westfalia, Germany; Landesanstalt für 

   Ökologie, Bodenordnung und Forsten, Recklinghausen Germany.2000 

♦ Earthworm populations in differently restored forest soils in Ochsenhausen, S-Germany; Forstliche Lehr- und 

   Versuchsanstalt Freiburg. 2000

♦ Nature protection in agricultural regions;  Fördergemeinschaft für Nachhaltige Landwirtschaft e. V., Bonn,

   Germany. 2000

♦ Acidic forest soil restoration by strip-wise tillage; Forstamt Kottenforst, Bonn, Germany. 1997-1998

♦ Development of a restoration concept for strongly acidic forest soils in Rhineland, Germany; Ministry of

   Environment, Düsseldorf, Germany. 1993-1999

♦ Simulation of leaching and degradation of pesticides in the soils; Consulting office Geolog, Brühl, Germany. 1990-

   1992

♦ Soil fauna in conventional and organic farms; Chamber of Agriculture, Rhineland, Germany. 1988-1992

♦ Soil erosion in S-Portugal; GTZ-Project. 1986-1987

♦ Efficiency of mulching in corn fields of tropical summer-rain regions in Togo; GTZ-Project. 1985

♦ Firewood Study in the Usambara mountains, Tanzanias; GTZ-Project. 1983-1984