Kvantifikacija poroznog sustava neporušenog tla primjenom različitih metoda

master's thesis

• Title (english): Undistrubed soil porosus system quanification using different methods
• Author: Jasmina Defterdarović
• Mentor: Vilim Filipović (mentor)
• Committee member: Vilim Filipović (predsjednik povjerenstva)
• Committee member: Mario Sraka (član povjerenstva)
• Committee member: Boris Lazarević (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Soil Amelioration); Zagreb
• Defense date and country: 2019-09-25, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Različitim zahvatima u poljoprivrednoj proizvodnji može doći do kvarenja strukture tla,
primjerice dezagregacijom golog tla oborinama, oksidacijom organske tvari koja je uvjetovana
pojačanom aeracijom uslijed obrade tla, mehaničkom disperzijom zbog zbijanja tla u vlažnom
stanju i usitnjavanja oruđima za obradu. Izgled i distribucija pora, posebice makropora, imaju
značajan utjecaj na tok vode i pronos tvari u nesaturiranoj zoni tla, što određuje i potencijal
pronosa i ispiranje agrokemikalija i onečišćivača kroz tlo. Zbog toga je bitno kvantificirati udio
i strukturu poroznog sustava u uzorku.
Cilj rada je primijeniti različite metode na neporušenom tlu i kvantificirati udio i strukturu
poroznog sustava u uzorku. Primjenom obilježivača kalcijeva klorida (CaCl2) određen je
volumen pora, briljantno plavim FCF bojilom (Brilliant Blue FCF) određeni su preferencijalni
tokovi u tlu, a rendgenskom kompjutoriziranom tomografijom (CT) reproduciran je stvarni
izgled poroznog sustava u tlu. Navedenim metodama se kvantificirao porozni sustav
neporušenog tla na istraživanom području Baštica.
Praćenje disperzije tvari u perkolatu provedeno je dodavanjem kalcijeva klorida koncentracije
100 mg L1 nakon čega je kolona ispirana. Koncentracije ispranih klorida određene su na
analizatoru kontinuiranog protoka. Koeficijent disperzije određen je pomoću HYDRUS-1D
programa. Briljantno plavo bojilo dodano je na kolonu tla te je nakon procjeđivanja bojila
kolona tla uzdužno prerezana i utvrđen je preferencijalni tok. Postotni udio obojenja obrađen je
u ImageJ programu. Kolona tla snimljena je rendgenskom kompjutoriziranom tomografijom
kako bi se utvrdio porozitet tla i stvarni izgled poroznog sustava u tlu. Postotni udio pora
utvrđen je u ImageJ programu uz potrebnu korekciju.
Istraživanjem je dobiven koeficijent disperzije za promatrani uzorak te je iznosio 8,5 cm2 min1,
a porozitet uzorka je bio 44,2 vol. %. Postotni udio obojenja primjenom briljantno plave
(preferencijalni tokovi) kretao se od 17,212 % do 33,362 %. Izradom 3D prikaza kolone tla
(poroznog sustava) utvrđeno je osipanje tla na dnu kolone kao i promjena strukture kolone.

Abstract (english)

Different management practices in agriculture can result in soil structure spoiling, for instance
disaggregation of the bare soil by downfalls, oxidation of the organic matter caused by
increased aeration due to the soil cultivation, mechanical dispersion due to the soil compaction
in humid and size degradation by agricultural tillage. Appearance and pore distribution,
especially of macropores have significant impact on water flow and solute transport in
unsaturated soil zone by determining transport potential of agrochemicals and pollution
leaching through soil. Therefore, it is important to quantify the proportion and structure of pore
system in the soil sample.
The aim of this thesis was to apply different methods to quantify the proportion and the structure
of the porous system in the undisturbed soil sample. This was determined with the application
of calcium chloride (CaCl2) as a tracer, preferential flow in the soil was estimated using Brilliant
Blue FCF and to reproduce real appearance of the porous system in soil the X-ray computed
tomography (CT) was used. Using the above mentioned methods porous system of the
undisturbed soil from experimental site Baštica was quantified.
Solute dispersion was estimated by adding calcium chloride in the concentration of 100 mg L-
1 and consecutive column elution (leaching). Concentrations of the leached chlorides were
determined by the continuous flow analyzer. Dispersion coefficient was determined using
HYDRUS-1D software. After the dispersion experiment Brilliant Blue FCF was added to the
soil column. Soil column was cut alongside and preferential flow was determined. Percentage
of blue staining was processed by ImageJ programme. In order to determine soil porosity and
reproduce porous system structure, the soil column was scanned with X-ray computed
tomography. Pore percentage was determined using the ImageJ software with the necessary
image corrections.
In this study, the dispersion coefficient of 8.5 cm2 min-1 was determined with the sample
porosity of 44.2 vol %. Applying the Brilliant Blue FCF tracer, staining percentage (preferential
flow pathways) value was determined in range between 17.212 % and 33.362 %. Using the 3D
imaging of the soil column, soil detoriation at the bottom of the column and changes in structure
were identified.

• Keywords: porozni sustav tla; disperzija; briljantno plavo bojilo; rendgenska kompjutorizirana tomografija; numeričko modeliranje
• Keywords (english): soil porous system; dispersion; Brilliant Blue; X-ray computed tomography; numerical modeling
• Language: croatian
• URN:NBN: urn:nbn:hr:204:736449
• Study programme: Title: Agroecology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/ magistra inženjer/inženjerka agroekologija (magistar/ magistra inženjer/inženjerka agroekologija)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2019-11-29 12:58:43