MEASUREMENT OF SOIL MEASUREMENT OF SOIL ELECTRICAL PROPERTIES FOR THE ELECTRICAL PROPERTIES FOR THE CLASSIFICATION OF MANAGEMENT CLASSIFICATION OF MANAGEMENT

VARIANTSVARIANTS

T. TÓTH1, A. RISTOLAINEN2,V. NAGY3,D. KOVÁCS1,CS. FARKAS1

1RISSAC, 2MTT, 3Institute of Hydrology Slovak Academy of Sciences

5th Alps-Adria Scientific Workshop 7 March 2006, Opatija, Croatia

Scheme of thScheme of thisis presentation presentation

-Objectives

-Research transects

-Instruments

-Analysis of differences between management variants

-Analysis of correlation between field values and laboratory data

-Conclusions

ObjectivesObjectives

Comparison of five field instruments, which are used as indirect techniques for the characterization of soil electrical properties, in order to distinguish classes of soil salinity, texture, vegetation and soil management.

First question: are the instruments useful or not? The answer is given by ANOVA between management variants.

Second question: what do the instruments tell us? The answer is given by correlation analysis between instrumental readings and laboratory measured values.

Data collectionData collection- Field measurements: ECa - electrical conductivity

- volumetric water content through - permittivity @ 1 m interval

- Soil sampling for analysing soil physical and chemical properties @ 5 m interval

Site descriptionSite description- Kiskunság Region, Hungarian Plain: mosaic-like soil cover- Three 70 m long transects on 10 Nov 2004

Rhoades et al.1999

Arrangement Amount/ratio

of soil constituents: water, charged particles, ions,

Conductivity EM & capacitance

  EM=EM=EMRC-EMRC-120120

M_ec=M_ec=Martek SCTMartek SCT

CF_ec=Con-CF_ec=Con-ductivity forkductivity fork

P_ecP_ec&&PP__perper==Plak Plak percometerpercometer

 

Volw=Volw=BR-30BR-30 

OperaOpera--tion tion principleprinciple

Electro-magnetic induction

Resistivity/conductivity

Resistivity/conductivity

Capa-citance

Capa-citance

OperaOpera--tion fre-tion fre-quencyquency

aprox. 10 kHz

120-1000 Hz 500 Hz 75 kHz for EC=P_ec50 MHz for wat.content= P_per

30 MHz

Specifi-Specifi-cationscations

Coil spacing 1 m

Dipole configuration,0.90m el. spacing

Wenner array,0.48 m el. spacing

   

Opera-Opera-tion tion depthdepth

1-1.5 m with vertical coil

~0.45 m ~0.25 m 0.20 m 0.10 m

Technical parametersTechnical parameters of instruments of instruments

OPERATION PRINCIPLE OF EM & ECa METERS

+ variants of heights

CF_ec

P_ec & P_per

P_ec & P_per

CF_ec

Instruments 1-CF_ecCF_ec (Conductivity fork, Geological Survey of Finland)-P_ecP_ec and P_per and P_per (cond/capac probe “Percometer”, Adek ltd., Est)

EM

M_ec

Volw

Instruments 2-M_ecM_ec (4 electrode resistivity sensor, Martek Instruments, US)

-EMEM (EMRC-120 instrument, Hungary)

-VolwVolw (capacitance probe “BR-30, RISSAC, Hungary)

Transect studies and differences between management variants

Non saline highest spot

Slightly saline spot

Saline lowest spot

TTransect ransect 2 – salt-affected grassland with small 2 – salt-affected grassland with small shift in texture and big change in elevationshift in texture and big change in elevation

Low lying extreme saline spot

1

10

100

1000

1 11 21 31 41 51 61 71

Log

(m

S m

-1)

M_ec20 M_ec40 Cf_ec

EM_ground EM_lifted P_ec

Extreme saline spot

ECa 0-0.45 m Cala Ach-F Art-F Puc Cam

Cases (n) 4 27 20 14 6

Calamagrostis \ - + + +

Ach-Festucetum \ + + +

Art-Festucetum \ - +

Puccinellietum \ +

Soil Moisture (0.10 m) Cala Ach-F Art-F Puc Cam

Cases (n) 4 27 20 14 6

Calamagrostis \ - - - +

Ach-Festucetum \ - - +

Art-Festucetum \ - +

Puccinellietum \ +

Wheat in the lowest & least sandy spot

Forest in highest & most sandy spot

TTransect ransect 3 – across 3 – across border border ofof forest and wheat forest and wheat field with largefield with large shift in texture shift in texture and big change in and big change in elevationelevation

Transect 3.

0

10

20

30

40

50E

C (

mS

m-1

)

Forest Headland Wheatsignificant differences between the 2 categories!!

Pasture

Maize fallow

Wheat

TTransect ransect 1 – different soil management and 1 – different soil management and crops, no changes in texture and elevationcrops, no changes in texture and elevation

Transect 1.

0

10

20

30

40

50E

C (

mS

m-1

)

Pasture Maize Headland Wheat

ECa 0-0.45 m

Pasture Wheat Maize Soil

Moisture (0.10 m)

Pasture Wheat Maize

Cases (n) 13 12 38 Cases (n) 13 12 38

Pasture / + - Pasture / - -

Wheat / + Wheat / +

Correlations

EM_

ground EM_ lifted

M_ec_ shallow

M_ec_ deep

CF_ec P_ec Volw

EM_lifted 0.95 1 M_ec_shallow 0.76 0.84 1 M_ec_deep 0.80 0.88 0.99 1 CF_ec 0.79 0.87 0.98 0.99 1 P_ec 0.89 0.95 0.92 0.94 0.94 1 Volw 0.36 0.25 -0.01 0.02 0.01 0.24 1 P_per 0.33 0.20 -0.04 -0.02 -0.09 0.13 0.81

Correlation coefficients between different instrument

readings in three transects (n=210). Values in Bold are

statistically significant (p<0.01)

1 .951 ** .755 ** .804 ** .720 ** .832 ** .782 **.951 ** 1 .840 ** .885 ** .815 ** .914 ** .872 **.755 ** .840 ** 1 .993 ** .981 ** .953 ** .979 **.804 ** .885 ** .993 ** 1 .977 ** .975 ** .987 **.720 ** .815 ** .981 ** .977 ** 1 .956 ** .990 **.832 ** .914 ** .953 ** .975 ** .956 ** 1 .988 **.782 ** .872 ** .979 ** .987 ** .990 ** .988 ** 1

EMSEMWECA20ECA40EC20EC2040EC40

EMS EMW ECA20 ECA40 EC20 EC2040 EC40

Correlation is significant at the 0.01 level (2-tailed).**.

Correlations between field measured and laboratory values

EC40

4.03.53.02.52.01.51.0.50.0

EC

A4

0600

500

400

300

200

100

0

-100

Vegetation

Headland

Forest

Maize

Wheat

Pasture

Camphorosmetum

Puccinellietum

Artemisio-Festucetum

Achilleo-Festucetum

Calamagrostis

Soil parameter M_ec

Clay (<0.002 mm) 0.73

Silt (0.002-0.05 mm) 0.30

Sand (>0.05 mm) -0.52

Humus (g g-1) -0.74

Water (g g-1) -0.21

pH 0.86

EC (mS) 0.98

Correlation between soil parameters sampled in the 3 transects at the depth of 0-0.20 m and soil electrical conductivity (n=45). Values in Bold are statistically

significant (p<0.01)

y = 0.8462x - 9.8752

R2 = 0.819

1.0

10.0

100.0

1000.0

0.0 10.0 20.0 30.0 40.0 50.0

Volumetric water ( m3 100 m3)

Lo

g(E

Ca

[m

S m-1

])

1. trans 2. trans 3. trans

MOIST40

22201816141210

EC

40

4.0

3.5

3.0

2.5

2.0

1.5

1.0

.5

0.0

Vegetation

Headland

Forest

Maize

Wheat

Pasture

Camphorosmetum

Puccinellietum

Artemisio-Festucetum

Achilleo-Festucetum

Calamagrostis

MOIST40

22201816141210

EC

40

.5

.4

.3

.2

.1

0.0

Vegetation

Headland

Forest

Maize

Wheat

Pasture

Camphorosmetum

Puccinellietum

Artemisio-Festucetum

Achilleo-Festucetum

Calamagrostis

Conclusions

•Soil salinity, textural differences and also management variants can be distinguished with decreasing statistical significance

• The methods show close correlation between instrumental readings and with the laboratory standard methods