Spatial variability of physical, chemical and biological properties of agricultural soils in Hidalgo State, Mexico.

The organic matter (OM) contained in soils is one of the properties of major interest due to its role in the structure and to its recognized influence in the dynamics of solutes. Characterization is therefore an aspect of greatinterest. The OM in soils cropped malting barley (Hordeum distichumL.) are relatively low, so that the uncertainty and possible errors of theanalytical method may determine spatial variability studies. In this paperwe developed and validated a method for analysis of OM according to thecriteria of ISO-17025 and designed a quality control, including a study of thevariability that the methodology introduced in the results. With the developed methodology has conducted preliminary sampling and sampling end of 39and 248 representative samples from a plot planted to malting barley Apan Township, south of the state of Hidalgo, Mexico, whose aim was to evaluate the number of samples needed to be taken to characterize this soil and this property (OM). The work was completed with a geostatistical study of thevalues of OM, which conclusions can be drawn for future sampling plans, development of simulation models and field-scale practical application offertilization problems.