During the past three years drought has severely affected agricultural productivity and has reduced attempts to rehabilitate agricultural areas affected by land degradation. Recurrent drought is a natural part of Australia's climatic cycle and drought management strategies should be included in all farm management plans. Over clearing and over grazing by introduced domestic and feral animals, as well as increased numbers of native species, have caused considerable vegetation destruction, leading to soil loss by both wind and water erosion. To reverse these trends, agriculturalists have been working to develop more sustainable agricultural systems. Dryland Agriculture Dryland agriculture consists of systems of production which rely exclusively on rainfall for the provision of water for crops and pastures.
Moisture is usually the limiting factor in production for at least part of the growing season.
It is practiced over the majority of the eastern and central divisions. It has contributed significantly to changes in water quality and flow in major river systems due to salt, nutrients, sediment and pesticides, has affected local and regional watertables, and has altered catchment ecology. The major management issues currently facing irrigated agriculture are competition for the water resource, rising watertables, decreasing water quality, and adverse impacts on aquatic and riverine environments. The impact of irrigation is not confined to the agricultural sector, since these issues affect all users as well as the general riverine environment. The price of irrigation water does not reflect its total economic cost.