The Soils of Northern Ireland The Soils of Northern Ireland

and their and their

Environmental SignificanceEnvironmental Significance

Part 1: Crawford Jordan, AFBI

Part 2: Barry Rawlins, BGS

TELLUS CONFERENCE 17-18 October 2007

AFBI Soil Classification Survey 1988-97

Soil pit photos with HorizonsBrown Podzolic

on Shale Till

Humic Gley

on Alluvium

B

A

C

B2

A

C

B1

HUMIC

GLEY

ALLUVIUM

AFBI Soil Survey Map 1:50,000

Urban

BE

SWG1

SWG2

SOIL TYPESSOIL TYPES

BELFAST

Lough

Neagh

Belfast Lough

Antrim

Lisburn

Larne

Annual Average Rainfall 1971-2000 (mm/yr)

Data copyright Met Office

Sperrins

Mournes

Antrim Hills

BELFASTCASTLEDERG

Major Soil TypesMajor Soil Types

4

15

7

57

13

4

%

*

24%;Peaty classes

16%;Freely draining

(Brown-earths)

54%;Poorly drained

(Gleyed soils)

Hydrology Of Soil Types (HOST)

CLASS % NI

2 7.1

3A 23.9

3B 26.1

4A 7.7

4B 22.9

5 3.1

5D 0.8

5U 3.9

Water 4.60

Ballylumford

CoolkeeraghNW gas pipeline

Soil Quality Indicators Measured by AFBI

Physical :

• Soil texture (% sand, silt and clay)

Chemical :

• pH

• Available-P (Olsen-P)

• Loss on ignition (LoI)

• % C

Largely based around indicators to monitor the

environmental quality of soils, especially those

relating to sustainable agriculture, including :

SOIL TEXTURE (% SAND, SILT, CLAY)

X SAND

SILT CLAY

TELLUS Survey Topsoil pH (CaCl2

extract)

Mean pH:

pH 6.0

pH 5.9

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

3.0 -

3.5

3.5 -

4.0

4.0 -

4.5

4.5 -

5.0

5.0 -

5.5

5.5 -

6.0

6.0 -

6.5

6.5 -

7.0

7.0 -

7.5

7.5 -

8.0

%

1988-97

2004-05

1995 vs 2005

pH

Comparison of soil ‘Available-P’ values by P-Index

Available-P (Olsen-P)

(Improved Grassland only)

Mean P:

21.5 mg/l

27.1 mg/l0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

Index-

0

Index-

1

Index-

2

Index-

3

Index-

4

Index-

5

Index-

6

%

1988-97

2004-05

P-Enriched

1995 vs 2005

TELLUS Survey Topsoil total-Phosphorus (as P2O

5)

Losses of agricultural-P from land to water

Total-P in stream waters

Concs > 32 ug TP/l

are eutrophic

(i.e. all except dark blue)

TELLUS SURVEY AFBI PREDICTION

Eutrophic waters

coloured RED

Comparison of Soil-Carbon values230 Matched samples covering all land uses (A-horizon)

1995 vs 2005

y = 1.11x

(R2 = 0.99)

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

0.0 10.0 20.0 30.0 40.0 50.0 60.0

%C (1995)

%C

(2005)

Relationship between

Soil Carbon (%C) and Loss on Ignition (% LoI)

AFBI WINTER 2004-05 5km grid

y = 0.55x - 2.03

(R2 = 0.97)

0.0

10.0

20.0

30.0

40.0

50.0

60.0

0 10 20 30 40 50 60 70 80 90 100

LoI (%) 2005

%C

2

00

5

% Carbon = (Loss on Ignition) / 2

(a) mean soil-C (mineral soils) = 5 %;

(b) 2004 estimate of total stocks of C in all NI soils to 100cm depth = 296 Mt C

LoI=10%

Acknowledgments(in alphabetical order)

Sampling :

Kevin Hamill, Alex Higgins, Tony McBride,

Brendan McRory, Jill Mellon, Raymond Stewart

and Brian Wallace

Sample Preparation and Analysis :

Irvine James, Hugh McKeating, Dermot McShane,

Gillian Nicholls, Peter Scullion and Alan Wright

All are AFBI staff from the Agri-Environment

Branch of AFESD based at Newforge Lane, Belfast.

TELLUS CONFERENCE 17-18 October 2007