master's thesis
Ispiranje nitrata pri gnojidbi lubenice rastućim dozama dušika

Ivan Miloloža (2016)
University of Zagreb
Faculty of Agriculture
Department of General Agronomy
Metadata
TitleIspiranje nitrata pri gnojidbi lubenice rastućim dozama dušika
AuthorIvan Miloloža
Mentor(s)Mario Sraka (thesis advisor)
Abstract
Intenzivni uzgoj povrća zahtjeva primjenu većih količina gnojiva, posebno dušičnih. Dušik kao nitratni ion nema sposobnost vezanja za adsorpcijski kompleks tla, te je sklon ispiranju u dublje slojeve i u podzemne vode. Ispiranje nitrata iz tla uslijed pretjerane gnojidbe predstavlja ne samo ekonomski, već i ekološki problem na što su posebno osjetljiva krška područja. Cilj rada bio je utvrditi utjecaj gnojidbe dušikom i načina pokrivenosti tla na ispiranje nitrata iz tla, pri uzgoju lubenica u agroekološkim uvjetima Valture. Pokus je postavljen po split-plot shemi, sa tri razine gnojidbe dušikom (60, 120 i 180 kg/ha) kao glavnim faktorom i tri različita načina pokrivenosti tla (golo tlo, slama, crni PE film) kao sporednim faktorom. Prosječni uzorci tla (0-30 cm) uzorkovani su 4 puta tijekom vegetacije lubenice po varijantama pokusa, a uzorci vode mjesečno iz gravitacijskih lizimetara. Koncentracije nitratnog dušika u tlu određene su pomoću kompleksa žute boje fenoldisulfonskom kiselinom (APHA, 1992), a nitratni dušik u vodama određen je metodom Chapman-a i Pratt-a (1961). Povećanje gnojidbe (60 – 180 kg N/ha) rezultiralo je očekivanim porastom koncentracija nitrata u oraničnom sloju tla (1,07 do 14,72 mg NO3 -/100 g tla) uz signifikantne razlike do sredine vegetacije, dok pri kraju vegetacije nije bilo značajnih razlika. Koncentracije nitratnog dušika u procjednoj vodi lizimetra varirale su od 11,90 mg NO3 -/l do čak 568,50 mg NO3 -/l ovisno o gnojidbi, pokrivenosti tla i količini procjedne vode, te fenofazi lubenice. U čak 78,9 % analiziranih uzoraka procjedne vode, utvrđene koncentracije nitrata prelazile su maksimalno dozvoljenu koncentraciju za pitke vode od 50,0 mg NO3 -/l. Porastom gnojidbe je raslo i godišnje ispiranje nitrata od 0,03 do 6,46 kg N/ha. Primjena crnog PE filma smanjuje ispiranje nitratnog dušika iz tla. Najviši prinosi lubenice (69,8 t/ha) ostvareni su gnojidbom od 180 kg N/ha, ali razlika u visini prinosa u odnosu na ostale varijante gnojidbe nije bila signifikantna. Primjenom crnog PE filma za malčiranje značajno se povisio prinos lubenice u odnosu na ostale varijante pokrivenosti tla.
Keywordsnitrates leaching fertilizer nitrogen watermelon
Committee MembersMario Sraka (committee chairperson)
Ivan Šimunić (committee member)
Ivanka Žutić (committee member)
GranterUniversity of Zagreb
Faculty of Agriculture
Lower level organizational unitsDepartment of General Agronomy
PlaceZagreb
StateCroatia
Scientific field, discipline, subdisciplineBIOTECHNICAL SCIENCES
Agronomy
Study programme typeuniversity
Study levelgraduate
Study programmeAgroecology
Academic title abbreviationmag. ing. agr.
Genremaster's thesis
Language Croatian
Defense date2016-07-07
Parallel abstract (English)
Intenzivne cultivation of vegetables requires the application of large quantities of fertilizer, particularly nitrogen. Nitrogen as nitrate ion has no capability for connecting to the adsorption complex of soil, and it is prone to leaching to deeper layers and groundwater. Leaching of nitrates from the soil due during fertlization is not only economic but also environmental problem especially in sensitive karst areas. The objective of this study was, to determine the effect of nitrogen fertilization and levels of coverage soil on nitrate leaching from the soil in the cultivation of watermelon in agroecological conditions of Valtura area. The experimental design was split-plot scheme, with three levels of nitrogen fertilization (60, 120 and 180 kg/ha) as the main factor and three different coverage of the soil (bare soil, straw, black PE film) as a secondary factor. Average soil samples (0-30 cm) were sampled four times during the growing of watermelons and a sample of water per month from gravity lysimeters. The concentrations of nitrate nitrogen in the soil are determined using a complex yellow color with fenoldisulfonic acid (APHA, 1992), and nitrate nitrogen in the water is determined by the method of Chapman and Pratt (1961). Increasing fertilizer (60-180 kg N/ha) developed as expected with increased nitrate concentration in the upper layers of the soil (from 1.07 to 14.72 mg NO3 -/100 g soil), with significant differences to the middle of the growing season, until the end of the growing season was not significant differences. The concentrations of nitrate in percolating water of lysimeters ranged from 11.90 mg NO3 -/l up to 568.50 mg NO3/l depending on fertilization, soil coverage, the amount of percolation water and stage of development of watermelon. In even in 78.9 % of the analyzed samples of percolation water, determined concentrations of nitrates are exceed the maximum allowable level for drinking water of 50.0 mg NO3 -/ l. The increase of fertilization caused increased nitrate leaching from 0.03 to 6.46 kg N/ha per year. The use of black PE film significantly reduces the nitrate leaching from the soil. The highest yield of watermelon (69.8 t/ha) was obtained by applaying 180 kg N/ha, but the difference in yields compared to other variants of fertilization were not significant. The application of black PE film for mulching significantly increased the yield of watermelon compared to other variants of soil coverage.
Parallel keywords (Croatian)nitrati ispiranje gnojidba dušik lubenica
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:204:101747
CommitterValentina Bezek