THE ROLE OF COMPOSTED ORGANICS IN A SUSTAINABLE FUTURE

Abstract

Listen

Translate article

The application of waste reduction, reuse and recycling concepts to organic residues is an excellent example of a problem (land filling organic residues) creating a solution, when they are composted and used in vegetable production to reduce environmental impacts and fertiliser use. In Western Australia, significant environmental concerns are associated with horticultural production on coarse sandy soils that overlay unconfined shallow aquifers on the coastal plain. The potential for co-composting urban and agricultural organic residues led to the Department of Agriculture and Food investigating the use of compost in horticulture. Work commenced in 1996 and early results were encouraging. This resulted in a nationally funded project to quantify and promote the benefits of using compost in vegetable production. The work initially quantified nutrient contributions and investigated the interaction with a clay soil amendment. More recently work has investigated relationships between productivity and soil nitrogen fertility. It will be argued that the use of compost by vegetable growers and other sectors of horticulture would have been greater if the implementation processes had followed, rather than largely preceded the development of strategic planning to guide the diversion of organic wastes from landfill. Grower uptake has been hampered by resistance to change, a limited ability to adapt fertiliser practices to accommodate the organic nutrient inputs and the inability to attach financial benefit to improvements in environmental outcomes. The paper also discusses the current diversion of household derived organics by composting the mixed waste component derived from the current two bin collection systems. Food security, zero waste, maintenance of soil health and potential carbon sequestration are considerations that underpin a sustainable society. Policy settings focussing on soil protection and source separate collection could better couple the recycling of organic residues with the production, and consumption of fresh food, and a more sustainable society.