Another one of our ventures this week took us to some South Australian Mallee soils . A major issue in these soils is ensuring that every rainfall event counts. Non-wetting soils are typically soils which contain a high percentage of sand and as a result of microbial degradation of organic matter a wax layer coats the outside of the sand grains. As a direct result when wax coated sand grains come into contact with one another they result in reduced water infiltration.
This leads to rapid water ponding events that rapidly leads to runoff and pooling in depressions in the landscape. The reduced water infiltration rates results in much of the rainfall not being utilised, let alone even entering the soil where the rain fall lands. This has depleting impacts on crop production especially when trying to germinate and establish annual crops.
Many farmers are now looking to apply products on the soil surface or placed near the seed to improve water harvesting into the planted furrow.