Varijabilnost reakcije tla u ovisnosti o rastućim dozama mineralne dušične gnojidbe

master's thesis

• Title (english): Variability of soil reaction under different mineral nitrogen fertilization levels
• Author: Mateo Koren
• Mentor: Aleksandra Perčin (mentor)
• Committee member: Aleksandra Perčin (predsjednik povjerenstva)
• Committee member: Ivana Šestak (član povjerenstva)
• Committee member: Aleksandra Bensa (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (General Agronomy); Zagreb
• Defense date and country: 2018-05-11, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Suvremena konvecionalna proizvodnja ratarskih usjeva nezamisliva je bez mineralne dušične gnojidbe no mnogobrojna znanstvena istraživanja ukazuju da dugogodišnja gnojidba dušikom uzrokuje zakiseljavanje tla, naročito onim gnojivima koja sadrže dušik u amonijskom obliku iz razloga što tijekom procesa nitrifikacije dolazi do oslobađanja protona (H+). Zakiseljavanje tla se višestruko negativno odražava na fiziološke, kemijske i biološke značajke tla kao i na mikrobiološku aktivnost i mobilnost pojedinih kemijskih elemenata.
Istraživanje u sklopu ovog diplomskog rada provedeno je na osnovu rezultata uzoraka tla prikupljenih tijekom 20 godina istraživanja (1996. – 2016.) sa poljskog pokusa na lokalitetu Potok smještenog u području zapadno-panonske poljoprivredne podregije Republike Hrvatske. Istraživanje je uključivalo šest gnojidbenih tretmana (0, 100, 200, 250, 300 kg N ha-1 te 250 kg N ha-1/+ ZT+CaCO3/dolomit) a uzorkovanje je provedeno na tri dubine tla (0-30, 30-55 i 55-80 cm). Reakcija tla određena je potenciometrijskom metodom i to u suspenziji tla sa 1 mol/L otopini kalij klorida u omjeru 1:2,5 (w/v).
Rezultati istraživanja ukazuju da je reakcija tla kroz istraživano razdoblje (1996. – 2014.) varirala sa koeficijentima varijacije u rasponu od 5,11 % do 16,7 %. Tako je relativno najniža reakcija iznosila 3,60 a zabilježena je 2009. godine u površinskom sloju (0-30 cm) na tretmanu s 200 kg N/ha te u podpovršinskom sloju (30-55 cm) na tretmanu s 300 kg N/ha, dok je relativno najviša reakcija iznosila 6,60 u najdubljem sloju (55-80 cm) a zabilježena je 2014. godine na tretmanu s 300 kg N/ha. Rastuće doze dušika (200, 250 i 300 kg/ha) utjecale su na značajno smanjenje reakcije u površinskom (0-30 cm) i podpovršinskom sloju (30-55 cm) u odnosu na kontrolu. Zakiseljavanje je najizraženije u površinskom sloju tla na tretmanu sa 250 kg N/ha. Na pokusnoj površini 2014. godine primijenjeno je agrovapno koje je prema rezultatima iz 2016. godine značajno povisilo reakciju tla na kontrolnom tretmanu te na tretmanima sa 250 i 300 kg N/ha. Zeolitni tuf, CaCO3 i dolomit u kombinaciji sa 250 kg N/ha utjecali su na značajno povećanje reakcije tla u odnosu na tretman sa samo primijenjenih 250 kg N/ha i to u površinskom i podpovršinskom sloju.

Abstract (english)

Modern agriculture is unthinkable without use of mineral nitrogen fertilizers but many scientific studies indicate that long-term nitrogen fertilization affected on soil acidification, particularly with fertilizers which contain nitrogen in ammoniacal form because of the release of protons (H+) during the process of nitrification. Soil acidification has many negative impacts on physical, chemical and biological properties as well as on microbiological activity and mobility of some chemical elements.
Research for this master thesis was conducted based on results of soil samples collected during 20 years period (from 1996 to 2016) from experimental trial at Potok location (west-panonian subregion of Croatia) from six different treatments (0, 100, 200, 250, 300 kg N ha-1 and 250 kg N ha-1/+ ZT+CaCO3/dolomite) on a three different soil depths (0-30, 30-55 and 55-80 cm). Soil reaction was determined by potentiometric method in suspension of soil and 1 mol/L potassium chloride solution in ratio 1:2,5 (w/v).
Results revealed that during the investigation period from 1996 to 2014 soil reaction varied with coefficient of variation from 5,11 % do 16,7 %. Relatively the lowest pH value was 3,60 and it was recorded in 2009 in a surface layer (0-30 cm) on treatment with 200 kg N/ha as well as in a subsurface layer (30-55 cm) on treatment with 300 kg N/ha, while relatively the highest pH value was 6,60 and it was recorded in 2014 at the deepest soil layer (55-80 cm) on treatment with 300 kg N/ha. Increased levels of nitrogen (200, 250 and 300 kg/ha) significantly decrease soil reaction in a surface (0-30 cm) and subsurface layer (30-55 cm) compared with a control treatment. Soil acidification was most prominent on a surface layer at treatment with 250 kg N/ha. In 2014 lime was applied on the experimental field which according to the results from 2016 influenced on significantly increasement of pH value on a control treatment as well as on a treatment with 250 and 300 kg N/ha. Zeolite, CaCO3 and dolomite aplication combined with 250 kg N/ha significantly increased soil reaction on surface and subsurface layer compared to treatment with only 250 kg N/ha.

• Keywords: dušična gnojidba; kiselost tla; kalcifikacija
• Keywords (english): nitrogen fertilization; soil acidity; liming
• Language: croatian
• URN:NBN: urn:nbn:hr:204:449531
• Study programme: Title: Organic Agriculture with Agrotourism; Study programme type: university; Study level: graduate; Academic / professional title: magistar / magistra inženjer/inženjerka ekološke poljoprivrede i agroturizma (magistar / magistra inženjer/inženjerka ekološke poljoprivrede i agroturizma)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2018-05-30 09:01:46