Info

* Number of observations (n), mean, and standard deviation (Stdv) within each group are shown, and means indicated by the same letter are not significantly different.

* Number of observations (n), mean, and standard deviation (Stdv) within each group are shown, and means indicated by the same letter are not significantly different.

correlations were positive, except those between EMH and the sand fractions and K-HNO3. Measured ECa was unaffected by the clay content.

The soil properties selected for testing the commercial soil survey practice were soil water content, ignition loss, soil organic matter, silt content, and all sand fractions except medium sand. The sand fractions were naturally strongly intercorrelated, as were ignition loss and SOM (data not shown). However, ignition loss and SOM also correlated strongly with soil water content, as shown for SOM in Figure 13.1. For convenience, only soil properties having a low intercorrelation are presented in Table 13.2.

Mean SOM increased with each EMH class up to the highest class included in the test, and there were statistical differences between all seven classes (Table 13.2). The good match between the ECa zones (based on the commercial procedure) and the SOM content is illustrated in Figure 13.2. For ignition loss and soil water content, there were significant differences between six and five of the

0 0

Post a comment