Time to get CROSS with soils

29/08/2011 3:25:24 PM

Time to get CROSS with soils – new soil stability assessment

     



Ultra Centrifuge spins samples to 17,000rpm to remove clay colloids from solution

New research from the Waite Institute

 

Predicting soil stability has become more accurate thanks to the work of Alla Marchuk and Pichu Rengasamy from the Soils Group of the School of Agriculture at the Waite Campus.

Marchuk and Rengasamy have developed a new ratio for predicting soil stability called Cation Ratio Of Structural Stability (CROSS). The CROSS analysis targets the dispersive potential of a given soil and is proving valuable for gaining additional insight into how farmed soils operate in different conditions.

Sodium Adsorption Ratio (SAR) has commonly been used to assess dispersive soils. The CROSS analysis gives a more accurate representation of soil stability by addressing the flocculating power of calcium, magnesium, sodium as well as potassium. Until now the dispersive influence of potassium has been overlooked, however in many agricultural soils, potassium is as dispersive as sodium.

Injekta Research has been applying the CROSS analysis to agricultural and environmental systems while assessing different soils types throughout South Australia and Victoria this year. They have utilised APAL’s high speed ulta-centrifuge which is essential for removing clay colloids from solution, to accurately measure soluble cations. Applying the CROSS ratios has resulted in many soils being identified as potentially unstable that had previously not been identified as dispersive using SAR. For more information on Injecta Reseach’s early field investigations contact Michael Eyres on (08) 81720931.

     The paper “Cation ratio of soil structural stability” by Alla Marchuk and Pichu Rengasamy is available here.