master's thesis
Utjecaj značajki tla i klimatskih čimbenika na ponašanje terbutilazina u tlu

Zoran Bahat (2016)
Sveučilište u Zagrebu
Agronomski fakultet
Melioracije
Metadata
TitleUtjecaj značajki tla i klimatskih čimbenika na ponašanje terbutilazina u tlu
AuthorZoran Bahat
Mentor(s)Klara Barić (thesis advisor)
Abstract
Nakon primjene na tlo, herbicidi su podložni različitim procesima koji se dijele na procese gubitaka i procese razgradnje. U procesima gubitaka matična molekula se ne mijenja (zadržava svoj herbicidni učinak), ali ostaje biljci nedostupna, dok razgradnjom herbicid gubi svoj primarni oblik (razgrađuje se na različite herbicidno inaktivne sastojke), i time se gubi herbicidni učinak. U procese gubitaka herbicida ubrajaju se adsorpcija, apsorpcija, ispiranje i isparavanje, dok u procese razgradnje ulaze fotokemijska, kemijska i mikrobiološka razgradnja. Kojim procesima i u kojem intenzitetu će herbicid biti izložen ovisi o različitim pedološkim i klimatskim čimbenicima, fizikalno-kemijskim svojstvima herbicida te njihovim međusobnim interakcijama. Adsorpcija herbicida najviše ovisi o sadržaju gline, organske tvari i pH vrijednosti tla. Tla s visokim sadržajem gline i organske tvari vezat će na sebe veće količine herbicida. Također, kod smanjenog sadržaja vode proces adsorpcije je intenzivniji i obrnuto. Nedostatak oborina osim što smanjuje djelovanje herbicida, dovodi do akumulacije rezidua u tlu, koje mogu štetiti narednim kulturama u plodoredu. U tlima koja imaju veći kapacitet adsorpcije smanjeno je ispiranje i razgradnja herbicida što opet produljuje njegovu perzistentnost u tlu. Perzistentnost herbicida se označava poluvijekom raspada (DT50). U različitim pedoklimatskim uvjetima, vrijednost DT50 za isti herbicid će biti različita. Tako se za terbutilazin navodi poluvijek raspada od 88 do 116 dana, ali i 30 do 60 dana što vrijedi za biološki aktivna tla. Koliki je utjecaj temperature na perzistentnost, vidljivo je iz podataka da je kod temperature tla od 20°C poluvijek raspada iznosio 28,9 dana, dok je kod 10°C iznosio 147,6 dana. Topivost herbicida u vodi je važno svojstvo koje utječe na njegovo ponašanje u okolišu. Topivost terbutilazina u vodi iznosi 8,5 mg l-1, a atrazina 33 mg l-1 što upućuje na pretpostavku da je atrazin u tlu mobilniji herbicid od terbutilazina.
Keywordsterbuthylazine soil persistence herbicide residue moisture temperature
Committee MembersKlara Barić (committee chairperson)
Stjepan Husnjak (committee member)
Milan Mesić (committee member)
GranterSveučilište u Zagrebu
Agronomski fakultet
Lower level organizational unitsMelioracije
PlaceZagreb
StateCroatia
Scientific field, discipline, subdisciplineBIOTECHNICAL SCIENCES
Agronomy
Study programme typeuniversity
Study levelgraduate
Study programmeAgricultural Engineering
Academic title abbreviationmag. ing. agr.
Genremaster's thesis
Language Croatian
Defense date2016-07-11
Parallel abstract (English)
After application to the soil, herbicides are exposed to processes of loss and degradation. In processes of loss (adsorption, absorption, leaching and evaporation) stem molecule maintains its herbicidal effect, but stays unavailable for plants. In processes of degradation (photochemical, chemical and microbiological degradation) herbicide loses its primary form and therefore loses the herbicidal effect. What processes occur and in which intensity herbicide will be exposed depends on soil type, climate factors, physical and chemical properties of the herbicide and interaction between these factors. Herbicide adsorption depends mostly on clay content, organic matter and pH value of the soil. Soils with high clay content and organic matter adsorb greater amount of herbicides. Also, with reduced water content, the adsorption process is more intense and vice versa. The lack of precipitation leads to accumulation of residues in soil which can damage the next crop in rotation. In soils with higher adsorption capacity, leaching and degradation of herbicides are reduced which consequently extends its persistence in soil. Herbicide persistence is measured by half-life (DT50). Herbicide half-life varies with different soils and climate conditions. Therefore, the half-life of terbuthylazine varies between 88 and 116 days, or 30 to 60 days in biologically active soils. Soil temperature also has significant impact on persistence of terbuthylazine in the soil. At soil temperature of 20°C terbuthylazines half-life was 28,9 days, while at 10 °C it was 147.6 days. The herbicide solubility in water is an important characteristic that affects its behavior in environment. Solubility of terbuthylazine in water is 8.5 mg l-1, while for atrazine it is 33 mg l-1. That leads to assumption that atrazine has a greater mobility than terbuthylazine.
Parallel keywords (Croatian)terbutilazin tlo perzistentnost rezidue herbicida vlaga temperatura
Resource typetext
Access conditionAccess restricted to students and staff of home institution
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:204:600875
CommitterValentina Bezek