Water repellent soils are a major production constraint on many sandy and gravelly textures soils across Southern Australia. These soils are challenging to establish crops and achieve adequate weed control. Often the only way to correct this water repellence is by applying and incorporating large amounts of clay. This is a costly and timely process that can be achieved either by clay spreading or clay delving and then incorporating by either offset discs or preferably by spading. The use of EM and Radiometric soil surveying can greatly assist in making well informed decisions on how to implement a successful claying program.
Delving clay on non wetting duplex soil.
Imants rotary spader for incorporating clay.
John Deere Scrapers operating in clay pit.
EM map showing areas of low conductivity (red) that are deep sands and high conductivity (blue) that represent soils with high clay content. With strategic soil coring PAA have found a strong correlation usually exists between increasing conductivity and depth to clay.
A selection of soil cores taken across the EM survey area from low conductivity (red) through to high conductivity (blue) that clearly illustrate the correlation between increasing EM and depth to clay.
By combining the EM map and soil coring to measure depth to clay, PAA can now make a depth to clay map that shows light brown as deep sand and dark brown as clay to the soil surface. This map can now be used for numerous applications such as selecting and locating clay pits close to areas of deep sand that require clay spreading to increase efficiency of spreading machinery. The map also shows areas where clay is at suitable depth where it can be delved. These types of maps can be used in paddock as a background layer on most modern controller screens.
Airborne imagery showing the effect on crop establishment from claying non wetting sand where red is low crop biomass and poor crop establishment and blue is high crop biomass and good crop establishment.