Information

Key findings

There is a strong correlation between pasture cover and soil loss. For all four soil types, soil loss decreased as cover increased. When cover was 70% or greater, soil loss was ten times less than for bare soil (0% cover).

The K1 values for Beer and Neara soils are lower than for Beppo soil. Compared with Beppo, both Beer and Neara soils have higher organic carbon and moderate to strong surface aggregates. The K2 erodability factors suggest that under cultivation, Beppo and Pinch soils would be more erodible than the Neara and Beer soils.

Pinch and Beppo have similar surface soil organic matter content and structure, however there is a significant difference between their soil loss and K1 values. This result could be due to differences in surface soil texture as Beppo has a clay loam surface while Pinch has a coarse sandy loam surface. Research suggests that soils with a clay loam surface texture are more erodible than those with a sandy textured surface soil.

Results from the rainfall simulation indicate that soil loss is lowest for Beer due to higher infiltration rates and lower runoff and because the K1 factor indicates this soil type is inherently less erodible. Beppo is the most erodible soil while Beer is the least erodible soil. Pinch and Neara fall between the two.

When bare, there is no significant difference in infiltration and runoff for the Neara, Pinch and Beppo sites. When cover is present, Pinch and Neara have a much higher infiltration rate and lower runoff rate that Beppo.

For all treatments, including high cover, a large proportion of rain became runoff for Neara, Pinch and Beppo soil types. Under high cover, little runoff occurred with Beer soil type.

Key table and figures extracted from data, literature and miscellaneous publications

Various clippings

 

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