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 the nitrogen and phosphorous levels evident in runoff from plots in the Queensland Murray Darling Basin.

Methods (brief)

Nitrogen and phosphorous levels in rainfall and runoff samples were collected over three years for 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; and
  • Nutrient export rates for the nested catchments did not correlate well to land use.

Table 3. Average suspended sediment and nutrient concentrations for Pittsworth nested sites (Titmarsh et al. 2009)

Catchment

Average suspended sediment g/L

Average Total Nitrogen mg/L

Average Total Nitrogen suspended mg/L

Average Total Nitrogen dissolved mg/L

Average Total Phosphorus, mg/L

Average Total Phosphorous dissolved

mg/L

Average Total Phosphorus suspended mg/L

Arnold

0.83

1.54

0.43

1.11

3.42

0.73

2.70

Galligan’s Contour

4.13

5.71

2.70

3.01

4.28

0.41

3.87

Galligan’s Gully

4.50

2.51

0.96

1.55

2.90

0.46

2.44

Rocky Creek

29.90

5.21

2.32

2.13

13.21

0.22

13.02

Location

Pittsworth

Related studies

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

 

Level 2, level 3, level 4, and level 5