The use of models of soil pedogenic processes in understanding changing land use and climatic change

Publisher Summary This chapter the functioning of agroecosystems as one aspect of changing land use in varying atmospheric conditions. The chapter illustrates the current status of the agroecosystems, explores how this current state was reached, and predicts long-term effects of existing and new management practices, changing weather patterns, and impending climate change on soil quality and agricultural productivity. An agroecosystem is an interactive group of biotic and abiotic components, some of which are under human control, that form a unified whole (ecosystem) for the purpose of producing food and fiber. The major driving variables are tillage, crop management, and changing climate patterns. Soils, in common with many ecosystems, have variables that operate at slow, intermediate, and fast rates. Variables such as soluble salts are highly dynamic, varying over season and reaching tentative equilibrium in a few years, whereasorganic matter levels have a time dimension of decades to centuries with carbonate and particularly clay weathering having a scale of millennia in semiarid climates.