Institute of Soil Science and Soil Geography 
Research activities on Tropical soils


Soil organic matter stability of Terra Preta soils (red indian black earth) in the Amazon region, Brazil

Optimizing Biomass Production in a Runoff Agroforestry System in Northern Kenya

Effects of land-use changes on soil fertility in the silvi-pastoral system of Northern Tanzania

Water and nutrient fluxes as indicators for stability of different land use systems on the Terra firme near Manaus
Fate of agrochemicals in the Pantanal Basin of Mato Grosso, Brazil

Nutrient budget in undisturbed and disturbed ecosystems of the South Ecuadorian Andes

Water and nutrient fluxes as indicators for sustainable land use in the Cerrado region of Brazil


Optimizing Biomass Production in a Runoff Agroforestry System in Northern Kenya

Period: 1994-1997

Location: Northern Kenya

Responsible:Johannes Lehmann

Objectives: - determination of nutrient fluxes in agroforestry with hedgerow intercropping in a semiarid tropical environment

- influence of intercropping, planting density and pruning intensity

- below-ground tree-crop interactions concerning soil nutrients and roots

Methods: soil chemical analyses (including different soil nutrient pools, physical fractionation, lignin, sugars, 13C and 31P NMR), plant analyses, tensiometry, suction cups, exchange resin boxes, heat pulse technique, minirhizotron, destructive root sampling, tracer techniques (N-15)


Project title: Effects of land-use changes on soil fertility in the silvi-pastoral system of Northern Tanzania

Responsible:Johannes Lehmann

Period: 1997-1998

Location: Northern Tanzania

Objectives: - effect of large- and small-scale farming on soil organic matter and soil fertility in comparison to natural woodland

Methods: - field survey

- particle and aggregate size fractionation of soil and subsequent analyses of the chemical composition of soil organic matter (lignin, carbohydrates, amino-sugars, NMR spectroscopy), C- and N-mineralization
 
 


Title: Water and nutrient fluxes as indicators for stability of different land use systems on the Terra firme near Manaus

Responsible:Johannes Lehmann

Period: 1995-2001

Location: Manaus, Brazil

Objectives: - determination of nutrient and water fluxes in different land use systems

 comparing primary and secondary forests with multiple cropping systems and monocultures

Methods: - analyses of soil and plant nutrients, throughfall, stemflow, soil nutrient fluxes with tensiometry, suction cups, heat pulse technique (N-15; P-32) and natural abundance

- application of tracer techniques to follow pathways of nutrients



 
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Established: 08.09.1998
Last update: 14.05.2001