Information

Nitrogen and phosphorous in runoff from small catchments in the Queensland Murray Darling Basin increases with intensity of catchment land use

Level 1 General description

Purpose:

The purpose of this study was to determine the effect of land use and soil type on nitrogen and phosphorous levels in runoff from plots of various sizes in the Queensland Murray Darling Basin (QMDB).

Methods (brief)

Nitrogen and Phosphorous levels in rainfall and runoff samples were collected over three years from 31 plots (<10 ha in size), each with a particular land use and soil type combination and from three sets of larger nested catchments (3 - 200000 ha) with mixed land use / soils.

Key findings (brief)

  • Export of N and P from all the single land use / soil type plots was positively correlated with soil fertility and increased with land use intensity;
  • Nutrient export rates for the nested catchments did not correlate well to land use; and
  • Average rainfall TN and TP concentrations were 0.38 and 0.04 mg/L respectively.

Table 1. Suspended sediment and nutrient export rates for Charleville. Data for Croxdale unstocked not available. (Titmarsh et al. 2009)

Catchment

Suspended sediment export rate kg/ha/mm

Average suspended sediment concentration, g/L

Total Nitrogen export rate, g/ha/mm

Average Total Nitrogen concentration, mg/L

Total Phosphorous export rate

g/ha/mm

Average Total Phosphorous concentration, mg/L

Charleville – Croxdale stocked

7.0

3.6

27.3

2.2

4.9

0.3

Charleville – Croxdale unstocked

-

1.0

-

2.2

-

0.5

Charleville – Croxdale virgin

6.9

0.6

26.2

2.3

2.0

0.3

Location

Charleville

Related studies

The following sites were part of the same study - Killarney, Greenmount, Pittsworth, Theodore, Goondiwindi, Wallumbilla, Inglewood, Stanthorpe, Goomburra, and Toowoomba.

 

Level 2, level 3, level 4 and level 5