Sustaining National Water Supplies By Understanding The Dynamic Capacity That Humus Has To Increase Soil Water-holding Capacity
Despite volumes of technical advice from mainstream scientific disciplines and continued alteration of natural environments, conventional systems of land management have been unable to maintain or improve the sustainability of natural land and water resources.
Hydrological system breakdown as a result of land degradation is now threatening to severely impact upon agricultural as well as city water supplies.
This study has identified a possible solution to the problem of increasing water shortages by investigating the natural ecological processes which are responsible for creating robust water systems in nature, and suggesting that it is now time to redesign the management systems of an industrialized era which have failed to maintain soil and water resources.
A thorough review of literature to quantify the water-holding ability of humus indicates a biological solution is possible to the growing water crisis in Australia. The initial discussion describes the negative cycle of depletion created by falling humus levels, reduced water-holding ability and continuing land degradation in Australia. The main body of work discusses the complex nature of soil humus and the processes necessary to build soil humus levels, as well as an investigation as to a reliable guide for estimating the water-holding capacity of soils containing varying levels of soil humus at a catchment scale. Finally a number of farming systems are discussed which provide methods of increasing soil humus as well as ensuring that new systems of land management are designed to be truly sustainable.
The multi-faceted benefits of soil humus ensure that any well designed program to increase soil humus to improve hydrological functions would be equally beneficial in areas such as farm productivity and the abatement of greenhouse gases.
A major finding of this study was that the subject of soil humus is critically under studied and thoroughly underestimated as a component of land and water management systems. It was found that the water-holding ability and nutrient status of soils can be dramatically improved by the development of land management systems which enhance the creative processes of soil biology and the naturalised agro-ecosystem.
Co-incidentally, the improvement in soil humus levels leads to soil structural improvement and increased plant density and ground cover, greatly alleviating the damaging factors which cause land degradation and water system breakdown.
The quantitative results of this extensive review were to find that one part of soil humus was able to store approximately four parts of water, demonstrating significant potential gains in soil water storage capacity at a catchment level.
Finally it was concluded that national water suppliescan not only be sustained, but more importantly enhanced through the adoption of a better understanding of land management practices which enhance a dynamic state of soil humus developmentin Australian soils.