Submitted to: Encyclopedia of Soils in the Environment
Publication Type: Other
Publication Acceptance Date: April 17, 2003
Publication Date: October 27, 2004
Citation: Karlen, D.L. 2004. Productivity of soils. In: Hillel, D., editor. Encyclopedia of Soils in the Environment. Vol. 4. p. 168-174. Technical Abstract: This contribution to the Encyclopedia of Soils in the Environment focuses on soil productivity, a concept that encompasses soil fertility plus the inherent and management-related factors affecting plant growth and development. Soil productivity is generally measured in terms of inputs versus outputs, which for agronomic situations generally refers to water and/or nutrient input versus crop yield. The critical soil functions influencing productivity within any soil are those that provide physical support, a rooting media with plant-available water, air for respiration, and essential nutrients. Humankind can also have a tremendous impact on soil productivity through its effects on the dynamic soil properties. Agricultural management decisions regarding tillage, fertilization, crop rotation, irrigation, and drainage are among the practices that can significantly affect soil productivity. A comparison of two distinctly different soils is presented to illustrate the factors affecting soil productivity. Key factors included in productivity indices, processes leading to the loss of productivity, and strategies for restoring soil productivity are discussed.