Nutrient Balances for Australian Natural Resource Management Zones

Nutrient balances for Australian NRM zones

In 2001, the federal government published an "Australian Agricultural Assessment", as part of a National Land and Water Resources Audit (NLWRA) (see http://www.anra.gov.au/topics/agriculture/pubs/national/agriculture_contents.html) included an assessment of nutrient management in Australian agriculture including a farm-gate nutrient balance for N, P, K, S and Ca. These data are publically available, and are for the audit period around 1994 to 1996. Since that time farming systems have altered, Australia has been through the millennium drought, commodity prices have altered and there has been increasing interest in the interaction of nutrients in the environment.

Since the audit period, there has been no more data added, and this project will repeat the published procedures undertaken to recalculate the balances using contemporary data. The base geographic areas used will be the 58 Natural Resource Management zones (see below), and balances for N, P, K and S will be calculated and reported for each agricultural zone.



Nutrient removals will be estimated using Australian Bureau of Agricultural and Resource Science (ABARES) annual gricultural production, and the nutrient densities used for each type of product will be drawn from the same source tables used in the 2001 Audit.

Fertilizer use data is available from the Fertilizer Industry Federation of Australia, but these annual data are only available at a state level. To get to regional fertilizer use, data from the Australian Bureau of Statistics farm survey will be used. These data are collected each four years.

There are many assumptions implicit in undertaking such a balance, and the project will aim to use the same working assumptions as the NLWRA. Nutrient transfers within regions such as the use of manures or crop by-products will be included where reliable data are available.

The IPNI survey will enable comparisons in nutrient balance for each NRM zone to be assessed, as well as compared to the NLWRA values, which should give insights into nutrient management trends in Australia. It would be idea to link these balances to soil test data, and this will be a goal for future work in this area.