Sugarcane, like some other crops are known to exhibit diminishing yields over each return after the first year of planting. While there is no definitive causal attribute to this effect, it has been suggested that organic carbon depletion disturbs the ecological balance of the soil, or that consolidation of the soil diminishes hydraulic conductivity that affects the plant available water for early root growth.
The injection of fertilizers into the rhizosphere has delivered some benefits, however farmers are looking for better sustainable yields with improved brix levels. The ability to get one or two extra returns per field is the desired objective, with sustained investment in organic matter and soil ameliorants ploughed into these fields.
With the increase in inputs in soil preparation, there is now the realization of substantial leaching of nutrients from the farms into the Great Barrier Reef and that this leaching is predominantly surface runoff that would be captured in the soil if it were possible to apply it into the rhizosphere.
Some clay particularly in FNQ are acidic and prone to release aluminium ions which negatively influence crop growth. It maybe also that some this aluminum will also leach with nitrates during heavy rain fall.
Notwithstanding these issues, conventional wisdom promotes the addition of large volumes of calcium salts for the purpose of improving hydraulic conductivity. Though it may benefit the soil friability at the surface of application, the desired changes to hydraulic conductivity are in reality not sufficiently achieved. The accumulation of salts and its consequent increase in EC impacts poorly on root development and the consequential brix potential.
Where sugarcane is grown in a sandy environment, the need to retard drainage becomes the real objective of soil preparation. So while maintaining good soil friability, an increase in water retention can be realized with a more cost effective deployment of Aqua-Sil liquid systems.
Since achieving clay soil friability is somewhat problematic with the established paradigm, it is perhaps now the time to explore how changes to surface tension and charge balance can provide a new mechanism to enhance friability for better hydraulic conductivity.
It may well be time to also consider looking at CHT Carbon Coated Mineral Fertilizers that combine both CEC and AEC to optimize nutrient deployment.
Cane sugar, as well as other clay soil grown crops, could well benefit from the synergistic combination of Aqua-Sil Soil technology and CHT Carbon Coated Mineral chemistries, see here for information
More technical information on the trials with Sugarcane can be seen in the report attached below: