Nutrient Balances for Australian Natural Resource Management Zones

Estimating nutrient inputs and removals in Australian agricultural regions.


23 Jan 2013

2012 Annual Interpretive Summary

The amounts of N, P, K, and S applied as fertilizers and removed as agricultural commodities were calculated using the Australian Bureau of Statistics (ABS) data for 2007-08 and 2009-10 for all Australian Natural Resource Management (NRM) regions.

The mass of P in commodities was 43 and 50% of the mass applied as fertilizers in 2007-08 and 2009-10 (with respective national net inputs of 190 and 170 kt P). Regions with (commodity P)/(fertilizer P) < 0.3 and >10 kt P net input in both years were Murray, Murrumbidgee, Lachlan, and Glenelg Hopkins. Nationally, the mass of K in commodities was 2.5 and 3.1 times the mass applied as fertilizers in 2007-08 and 2009-10 (with respective net exports of 196 and 256 kt P). Regions with > 10 kt K net export and (commodity K)/(fertilizer K) >10 in both years were Wimmera, Northern and Yorke. The mass of S removed in commodities was 49 and 62% of the fertilizer mass applied in 2007-08 and 2009-10 (with respective national net exports of 91 and 62 kt P). Strong net additions of S in both survey years occurred in South-East (SA), South-West (WA), and Glenelg Hopkins. Nitrogen balance depends on the method used to calculate biological N fixation. Simply using fertilizer amounts, regions with strong net input of N were Port Phillip and Westernport, West Gippsland, Hawkesbury-Nepean, Wet Tropics, and Condamine.

These balances will be contrasted with land management practices and soil test values, as well as the 1992-1997 Land and Water Audit. Future work will include biological N into the N balance and publishing the data on all nutrients surveyed. ANZ-16