Biplob K. Saha1, Michael T. Rose2, Vanessa Wong3, Timothy R. Cavagnaro4 and Antonio F. Patti1

1School of Chemistry, Monash University, Clayton, Victoria, 3800, Australia2NSW Department of Primary Industries, Wollongbar Primary Industries Institute, Wollongbar, NSW 2477, Australia3School of Earth, Atmosphere & Environment, Monash University, Clayton, Victoria, 3800, Australia4School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, South Australia, 5064, Australia

Materials and Methods

Granules C:N C content (%) N content (%)

Brown coal-urea 1 (BCU 1) 1.0 40 22

Brown coal-urea 2 (BCU 2) 1.5 46 17

Brown coal-urea 3 (BCU 3) 3.0 49 9

Brown coal-urea 4 (BCU 4) 10.0 54 5

Figure 1: Preparation of brown coal-urea blends

The soil was treated with N @ 250 mg kg-1 soil. Equal

amount of N was added from different BCU granules

including urea.

Table 1: CN ratio and C and N contents of BCU blends

Results and Discussion

Figure 3: Ammonium (A) and nitrate (B) leached out from soil at

three different leaching events (Bars indicate standard error, n=5).

-20

-15

-10

-5

0

0 10 20 30 40 50

Depth

of so

il pro

file

(cm

)

Ammonium (mg kg-1)

Control Brown coal Urea

BCU 1 BCU 2 BCU 3

BCU 4-20

-15

-10

-5

0

0 30 60 90 120 150 180

Depth

of so

il pro

file

(cm

)

Nitrate (mg kg-1)

Control Brown coal Urea

BCU 1 BCU 2 BCU 3

BCU 4

Figure 5: Ammonium (A) and nitrate (B) content of soil at harvest

0

10

20

30

40

0 7 14 21 28 35 42 49

N2O

-N (

µg

kg-

1h

-1)

0

300

600

900

1200

1500

0 7 14 21 28 35 42 49

NH

3-N

(m

g m

-2d

-1)

Control Brown coal

Urea BCU 1

BCU 2 BCU 3

BCU 4

Figure 4: Daily N2O-N emission (A) and NH3 emission (B) from soil

Days after fertiliser addition Days after fertiliser addition

Conclusions

References(1) Raun, W. R. et al. Agron. J. 2002, 94, 815-820. (2) Dong, L. et al. Biol. Biochem.

2009, 41, 612-621. (3) Wang, Q. et al. Plant. Soil. 2010, 337, 325-339.

AcknowledgementsGrateful to Monash University for PhD scholarships and Brown Coal Innovation

Australia (BCIA) for funding the research.

(A)

(A)

(B)

(B)

0

1

2

3

4

5

15 30 45

NH

4+

leac

hed (

mg)

Time of leaching event (day)

Soil only

Brown coal

Urea

BCU 1

BCU 2

BCU 3

BCU 4

0

5

10

15

20

25

15 30 45

NO

3-le

ached (

mg)

Time of leaching event (day)

Soil only Brown coal

Urea BCU 1

BCU 2 BCU 3

BCU 4

(B)(A)

Introduction

The nitrogen efficiency of nitrogenous fertiliser is very poor and the transfer to plants seldom

exceeds 50% of added N1.

The low use efficiency of N is consequence of its losses by leaching, denitrification and volatilisation2

This lost N represents both an economic inefficiency and an environmental burden3

This study aims to increase N-use efficiency by blending brown coal with N fertilisers

The BCU blends were tested for N emissions under controlled

conditions according to the experimental set-up shown in Figure 2

Blending of BC with urea

significantly reduced

leaching and gaseous loss

of N.

BCU blends maintained

significantly higher amount

of N in the soil profile.

Greater amount of N will

be available for plants

over a longer period of

time.