Impacts of Climate Change On Soil Quality and Disease and Pest Incidence in Developing Countries.

Climate change is predicted to have many potential impacts on agroecosystems in food-insecure regions including decreased crop yields and food production.  Among the many factors affecting this potential decrease in food production are changes in soil quality and disease and pest incidence.  Soil quality factors that affect food production that may be altered are the amount of biomass going into soil organic matter, changes in soil temperature regimes, and alterations in soil hydrology and water relations. One possible effect of climate change is lower or excessive soil water content during critical periods of the growing season.  Other possible effects on soils are increased soil organic matter loss counterbalanced by higher biomass production in some regions, increased risk of soil erosion, change in cropping systems with possible subsequent negative effects on soil properties, and increased landslides and mudflows due to a higher incidence of high intensity rainfall events.  The risk of plant diseases and insect pests can be strongly affected by climate through changes in factors such as pest reproductive rates and the likelihood of overwintering or oversummering. Using the Andean Highland region as an example, the authors will discuss the risks associated with climate change and possible practices that would assist farmers in the region to adapt to climate change.  Among the suggested adaptations are soil water conservation measures to capture and reduce soil moisture loss, soil conservation practices to reduce soil erosion and landslides, improved irrigation methods, alternative crop species and varieties that are short season and drought- and frost resistant, increased use of soil fertility inputs including use of alternative organic amendments, improved crop residue management, and maintenance of genetic diversity.  It will be important that farmers have access to recommendations for adaptation strategies so that transitions can be as smooth as possible.