Résumé :
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The influence of soil properties on microbiological processes is often examined by comparing the behaviour of taxonomically disparate soils. One of the limitations of this approach is that the results can be confounded by the unmeasured properties which vary between soils of different type or between soils which have had different climatic and management histories. This study tested the hypothesis that the heterogeneity between 100 small contiguous undisturbed soil cubes (about 1.7 cm(3)), sampled from the surface of a very small field plot (14 by 14 cm), was sufficiently large to use for the exploration of how soil properties influence biological processes. After incubation of the soil for 35 days, the coefficients of variation for nitrate (NO3), ammonium (NH4), gravimetric water content (theta(g)), bulk density (ED), pH buffering capacity (pHBC), and pH were 28, 39, 27, 10, 13, and 2%, respectively. A multiple regression equation predicting nitrate concentration had an r(2) value of 0.89 and significantly included 4 predictor variables, with only pH being non-significant. These analyses confirmed the hypothesis.
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