2 - Quality control and quality assurance in applied soil microbiology and biochemistry

Abstract

The chapter discusses quality control and quality assurance in applied soil microbiology and biochemistry. Modern soil microbiology and biochemistry is confronted with new and different challenges. The answers to problems associated with soil microbiology and biochemistry must be concerned with the principal question of quality control and quality assurance. The related consequences exemplify the need for an accurate, reliable, and valid methodology to assure the highest achievable level of quality. Quality is a certain property of a process or a result, of which it is an inherent characteristic. Quality is examined by the determination of the levels of quality categories as precision, accuracy, reliability, representativity, validity, objectivity, reproducibility, relevance and applicability, and efficiency: the statistical aspect of data interpretation is the acceptance or rejection of the statistical hypothesis. The way of collecting data is preconditioned by the problem statement and the statistical methodology chosen to sample and analyze the observations. Four rules for experimental design to collect data can be specified: randomization, replication, blocking, and error control. In applied soil microbiology and biochemistry, statistical methods that are suited to describing, analyzing, and evaluating the information and quality of field data are important. An important point in the evaluation of soil data sets is the spatial analysis and display of the data. The objective of blocking is to control the variability caused by erroneous sources systematically.