Influence of post-harvest residues on properties ofhumic acids of different types of soilsMAŁGORZATA DRĄG and BOŻE#A DĘBSKA
University of Technology and Life Sciences,
Department of Environmental Chemistry, Bydgoszcz,
PolandHumic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

The aim of the work was to define the influence of the kind of
post-harvest
residues,
particularly
theirchemicalcomposition on a structure of humic acids coming fromdifferent kinds of soils. The study material is composed ofvegetable residues (a mixture of straw and roots) of corn,rape, sunflower, potato and rye.
This study was conducted within
the research project # # 310 3281 33 financed by
the Ministry of Scientific Research and Information Technology.
Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

The study material is composed of the following residues:

CornRape
Sunflower
PotatoRye
Which were incubated with the following kind of soils:
Haplic Luvisol
Chernozem
Haplic Arenosol
Haplic Gleysol

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

Chemical composition of post-harvest residues and share ofeasily-decomposing compounds (C1), slowly-(C2)and hard-decomposing compounds (C3)
AshCN

P

Kind of residues

C1C/N%

C2C3C/P

g/kg%

Corn (K)6,848713,61,835,8

270

19,462,618,0

Rape (Rz)

14,5

444

12,9

1,6

34,4

277

10,756,5

32,9

Sunflower (Sł)

10,6433

14,4

1,8

30,1

240

15,358,426,3

Potato (Zm)

31,7355

20,1

1,9

17,7

187

20,250,729,0

Rye (Ż)12,4455

9,7

2,0

46,9

227

9,655,335,1C1 –monosaccharides, proteins, starch
C2 – hemicellulose, cellulose
Humic Substances in Ecosystems 8, Šoporňa
C3 – lignine
13.-17.9.2009 Slovakia

Content of carbon and nitrogen in soils

Kind of soil

Corg
g/kg

#tg/kg

Corg/#t

Haplic Luvisol (Lo)

13,9

1,55

8,97

Chernozem (Hh)

21,1

2,53

8,34

Haplic Arenosol (Re)

5,1

0,93

5,48

Haplic Gleysol(Ge)

17,7

2,33

7,60

Humic Substances in Ecosystems 8, Šoporňa
13.-17.9.2009 Slovakia

The project has been carried out at the Department of Pedology
and Geology of the Slovak Agricultural University in #itra as amodel incubation experiment
Conditions of the experimentIncubation time: 0 days; 360 days
Incubation tempereture: 25°C
Moisture: 60 %FWC
Post-harvest residues mixed with soil material in ratio 1:10

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

The scheme of experiment
Symbol of variant

Variant

LoK-0

Haplic luvisol+ corn residues before incubation

LoK-360

Haplic luvisol+ corn residues after incubation

LoRz-0

Haplic luvisol+ rape residues before incubation

LoRz-360

Haplic luvisol+ rape residues after incubation

LoSł-0

Haplic luvisol+ sunflower residues before incubation

LoSł-360Haplic luvisol+ sunflower residues after incubation

LoZm-0

Haplic luvisol+ popato residues before incubation

LoZm-360

Haplic luvisol+ potato residues after incubation

LoŻ-0

Haplic luvisol+ rye residues before incubation

LoŻ-360

Haplic luvisol+ rye residues after incubation
Humic Substances in Ecosystems 8, Šoporňa
13.-17.9.2009 Slovakia

Research methods:

Humic acids according to Schnitzer were isolated from soil samples
without residues and mixed with residues before and after 360 days
incubation.
The extracted humic acids were analysed for:elementar composition

C, H, #, O
H/C, #/C, O/C, O/H, ω
Humic Substances in Ecosystems 8, Šoporňa
13.-17.9.2009 Slovakia

1,41,41,21,2Absorbancja

Absorbancja

Optical properties in range UV-VIS

1,00,80,60,4

1,00,8
0,60,40,20,20,00,0
230

280

330

380 nm230

Humic Substances in Ecosystems 8, Šoporňa
13.-17.9.2009 Slovakia

280330380 nmSusceptibility to oxidation

H2O2
Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

Infrared spectra in range 400 – 4000 cm-1ReReK-0

ReRz-0

ReSl-0T

ReZm-0ReZ-03800,0

3000

2000
cm-1

1500

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

1000,0Thermal properties

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

Hydrophillic-hydrophobic properties
HIL-2
HIL-1

0

HOB-2
HIL-3

5

HOB-3

HOB-1

1015

2025
czas – time, min.

Humic Substances in Ecosystems 8, Šoporňa
13.-17.9.2009 Slovakia

Content of carbon (in atomic %) in humic acids isolated from soil samples
without residues and mixed with residues before incubation

38C in atomic %3736353433323130
29
Haplic Luvisol

soil

K

Haplic Arenosol

Rz

SłZm

Ż

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

Content of carbon (in atomic %) in humic acids isolated from soil samples
without residues and mixed with residues before incubation

36

C in atomic %

35
34
33
32
31
30
Chernozem

soil

Haplic Gleysol

KRzSłZm

Ż

Humic Substances in Ecosystems 8, Šoporňa
13.-17.9.2009 Slovakia

Content of carbon (in atomic %) in humic acids isolated from soil samples
mixed with corn residues before and after incubation

36
35K-0K-360

3433
32
Haplic Luvisol

Chernozem

Haplic Arenosol

Haplic Gleysol

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

Content of carbon (in atomic %) in humic acids isolated from soil samples
mixed with rape residues before and after incubation

3635
Rz-0
Rz-3603433
32
Haplic Luvisol

Chernozem

Haplic Arenosol

Haplic Gleysol

Humic Substances in Ecosystems 8, Šoporňa
13.-17.9.2009 Slovakia

Content of carbon (in atomic %) in humic acids isolated from soil samples mixedwith potato residues before and after incubation

3635
3433Zm-0
Zm-36032313029
Haplic Luvisol

Chernozem

Haplic Arenosol

Haplic Gleysol

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

Content of hydrogen (in atomic %) in humic acids isolated from soil samples
without residues and mixed with residues before incubation50

H in atomic %

4846
44
4240
38
Haplic Luvisol
soil

Haplic Arenosol
K-0

Rz-0

Sł-0

Chernozem
Zm-0

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

Haplic Gleysol
ś-0Content of hydrogen (in atomic %) in humic acids isolated from HaplicArenosol mixed with residues before and after incubation

49484746450360

444342414039

cornrape

sunflower

potatoHumic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

ryeContent of nitrogen in humic acids isolated from soil samples without residues
and mixed with selected residues before and after incubation

43,5
32,52
1,5
10,50

Haplic Luvisol
gleba

Chernozem
Zm-0

Haplic Arenosol
Zm-360Ż-0Ż-360

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

Haplic Gleysol

UV-VIS spectrometryA280-defines the conten of compounds of lignin type
A465-content of the substance at the initial stage of decomposition
A665-reflects the content of substances showing a high degree ofhumification
A2/4- 280 nm and 465 nm absorbance ratio
A2/6- 280 nm and 665 nm absorbance ratio
A4/6- 465 nm and 665 nm absorbance ratio∆logK = logA400 – logA600

Humic Substances in Ecosystems 8, Šoporňa
13.-17.9.2009 Slovakia

Values of A2/4 ratio for soils’ HA without residues and mixed with residues
before incubation

121086420

Haplic Luvisolsoil

Chernozem

Haplic Arenosol

K-0

Sł-0

Rz-0

Zm-0

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

Ż-0

Haplic Gleysol

Values of A2/4 ratio for HA isolated from Haplic Luvisol without residues andmixed with residues before and after incubation

1098
7
65432
10

HaplicLuvisol

CornRape

Sunflower

0 days360 days

PotatoHumic Substances in Ecosystems 8, Šoporňa
13.-17.9.2009 Slovakia

RyeAverage values of ∆Au465 for soils’ HA without residues and before andafter incubation with residues

706050403020
100Haplic Luvisol

Chernozem

Haplic Arenosol

soil

369 days

0 daysHumic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

Haplic Gleysol

FTIR spectra of HA isolated from Haplic Luvisol without residues andbefore and after incubation with post-harvest residues

LoK
LoK

LoZ

%T %T

LoZ

%T %T

Lo

LoZm

LoZm

LoSl

1780,0Lo

LoSl

1500

1000,01780,01500

cm-1

Before incubation

1000,0cm-1

After incubation
Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

Values of DTA egzo2/DTGegzo2 parameter in soils’HA without any additions
and mixed with residues before incubation

76543210

Haplic Luvisol

Chernozem

soil

K-0

Rz-0

Haplic Arenosol

Sł-0

Zm-0

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

Haplic Gleysol

Ż-0Share of HIL fraction in soils’HA without any additions and mixed withresidues before incubation

403530
2520
15
1050

Haplic Luvisol
soil

Chernozem

Haplic Arenosol

K-0

Sł-0

Rz-0

Zm-0

Ż-0

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

Haplic Gleysol

Share of HIL fraction in HA isolated from Haplic Luvisol without residues andmixed with residues before and after incubation

35302520151050CornRape

Sunflower0 days

Potato360 days

Humic Substances in Ecosystems 8, Šoporňa
13.-17.9.2009 Slovakia

RyeValues of HIL/HOB ratio for soils’ HA without residues and mixed with residues
before incubation

0,60,50,40,30,20,10

Haplic Luvisol
soil

Chernozem

Haplic Arenosol

K-0

Sł-0

Rz-0

Zm-0

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

Ż-0Haplic Gleysol

Values of HIL/HOB ratio for HA isolated from Haplic Luvisol mixed withresidues before and after incubation

0,60,50,40,30,20,10CornRapeSunflower0 days

Potato360 days

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

Rye

CO#CLUSIO#S

Humic Substances in Ecosystems 8, Šoporňa
13.-17.9.2009 Slovakia

1.
The introduction of post-harvest residues into the soils
coused in molecules of humic acids – irrespective from typeof soil and chemical composition of residues:
increase content of hydrogendecrease value of internal oxidation degreeincrease values of coefficients A2/4 and ∆ logK
decrease share of hydrophillic fraction as well as theshare HIL/HOB
The changes others parameters were not so unambiguous
and they were determined both the type of soil as well as thekind of post-harvest residues.
Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

2.
The growth of ‘maturity’ degree of humic acids molecules wasrelated in general with:decrease of the hydrogen contents
increase of the nitrogen and oxygen contents
increase of internal oxidation degree
decrease of the values of the absorbance coefficients (A2/4, A2/6 i∆∆logK)
increase of the share hydrophillic fraction and the share i HIL/HOB

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

3.
The pattern of FTIR spectra of the soils HA without residues andmixed with residues before and after incubation permits to arrange
plant residues in dependence on their intensity of decomposition in
the following order:
potato ≥ sunflower > rape > corn ≥ rye

Humic Substances in Ecosystems 8, Šoporňa13.-17.9.2009 Slovakia

4.
Humic acids of soils mixed with post-harvest residue showed, ingeneral, higher values of parameter DTAexo2/DTGexo2 than thehumic acids of soils without additives. The process of post-harvest
residue decomposition was connected with a decrease in the valueof the parameter corresponding to the burning heat of humic
acids.

Humic Substances in Ecosystems 8, Šoporňa
13.-17.9.2009 Slovakia

THA#K YOU FOR
ATTE#TIO#Humic Substances in Ecosystems 8, Šoporňa
13.-17.9.2009 Slovakia