individual publications

• academic article

  • Modeling the impact of natural resource-based poverty traps on food security in Kenya: The Crops, Livestock and Soils in Smallholder Economic Systems (CLASSES) model..  Food Security.  4:423-439. 2012
  • Long-term soil quality degradation along a cultivation chronosequence in Western Kenya.  Agriculture, Ecosystems & Environment.  141:86-99. 2011
  • Anthropogenic and climate influences on biogeochemical dynamics and molecular-level speciation of soil sulfur.  Ecological Applications.  19. 2009
  • Anthropogenic and climate influences on biogeochemical dynamics and molecular-level speciation of soil sulfur. .  Ecological Applications.  19:989-1002. 2009
  • Nutrient constraints to tropical agroecosystem productivity in long-term degrading soils.  Global Change Biology.  14. 2008
  • Long-term impacts of anthropogenic perturbations on dynamics and speciation of organic carbon in tropical forest and subtropical grassland ecosystems.  Global Change Biology.  13:511-530. 2007

• conference poster

  • Soil fertility degradation and management in the highlands of Kenya.  147-11. 2006

• document part

  • Soil organic matter stabilization and associated degradation threshold dynamics 2006
  • Biogeochemical characteristics of organic matter fractions that confer thresholds during soil degradation 2004
  • Nitrogen fluxes in Soils Amended with Manure and Tithonia on a Chronosequence 2004