Chapter 9 Soil quality control

Abstract

The search is on for acceptable methods to quantify soil quality and its change in response to land management practices. This chapter describes a methodology for soil quality control based on an analogy with the quality control of manufactured products using statistical quality control (SQC) concepts and procedures. It discusses the fundamental principles and concepts of SQC in an effort to provide a basis for applying these principles to the task of sustaining and improving the quality of soils. Quality control involves both monitoring and control. Monitoring is the regular surveillance of the condition of something, whereas control means to influence or regulate. Monitoring keeps track of quality but it does not change it, whereas the main objective of SQC is to change quality. Because one goal of sustainable land management should be to achieve good soil quality, it is necessary to go beyond simply monitoring and to focus on quality management. The use of SQC for soil quality evaluation was first proposed by Pierce and Larson (1993) as a means of developing criteria to evaluate sustainable land management.