Uticaj različitih režima navodnjavanja černozema pod šećernom repom na prinos korena i šećera

Four-year studies were carried out on the experimental field "13th May" in Zemun Polje to determine the optimum irrigation scheduling of chernozem planted with sugar beet, i.e. the lowest number of water applications for producing maximum root and sugar yields. The studies comprised 3 variants of irrigation scheduling of the chernozem soil: optimum chernozem water regime formed from sugar beet sowing to its technological maturity, optimum chernozem water regime formed from phenological stage of crown growth to sugar beet technological maturity, and optimum chernozem water regime formed from phenological stage of intensive root growth to sugar beet technological maturity. Natural water regime of chernozem planted with sugar beet was used as a control. Irrigation was applied by sprinkling method, and its rate and time were determined by the method of water balance of effective rhizosphere zone. Pluviometric regimes during the study period comprised one wet, one normal, and two dry hydrological years. Therefore, natural Corresponding author: Gordana Matović, Katedra za navodnjavanje, odvodnjavanje i konzervaciju zemljišta Poljoprivredni fakultet Zemun, Nemanjina 6, E-mail: goleboleŽEunet.yu. water regime of chernozem conditioned very fluctuating and, on average, low yields of root (48.2 t-ha-1) and sugar (7.34 t-ha-1). The studies showed that irrigation increases sugar beet root yield, on average, by 87%, but tends to decrease sugar content, so that increase of sugar total amount is, on average, 81%. Maximum yields of root (85.3 t-ha-1) and sugar (12.7 t-ha-1) are obtained by irrigation applied from the phenological stage of crown growth to sugar beet technological maturity, with average irrigation rate of 416 mm distributed in 8 applications. Thus, 77% of sugar beet genetic potential is utilized in contrast to 44% under conditions of soil natural water regime. Higher irrigation rates result in lower yields.U cilju određivanja optimalnog režima navodnjavanje černozema pod šećernom repom, odnosno najmanjeg broja zalivanja radi ostvarenja maksimalnih prinosa korena i šećera, na oglednom polju "13. Maj", u Zemun Polju su četvorogodišnjim istraživanjima obuhvaćene 3 varijante irigacionih vodnih režima černozema: - optimalni vodni režim černozema formiran od setve do tehnološke zrelosti: - optimalni vodni režim černozema formiran od fenofaze porasta glave korena do tehnološke zrelosti: - optimalni vodni režim černozema formiran od fenofaze intenzivnog debljanja korena do tehnološke zrelosti i prirodni vodni režim černozema pod šećernom repom, kao kontrolni. Navodnjavano je sprinkler metodom, normom i rokovima određivanim metodom vodnog bilansa efektivne zone rizosfere. Pluviometrijski režimi u kojima su izvedena istraživanja obuhvatila su jednu vlažnu, jednu normalnu i dve suve hidrološke godine. Shodno tome, prirodni vodni režim černozema uslovio je vrlo kolebljive i prosečno niske prinose korena (48,2 th-1) i šećera (7,34 tha-1). Istraživanja su pokazala da se navodnjavanjem prinos korena šećerne repe prosečno povećava za 87%, a zbog trenda smanjenja digestije navodnjavanjem prosečno povećanje ukupne količine šećera je 81%. Maksimalni prinosi korena (85,3 th-1) i šećera (12,7 tha-1) dobijaju se navodnjavanjem od fenofaze porasta glave korena do tehnološke zrelosti šećerne repe, prosečnom normom od 416 mm, raspoređenom u 8 zalivanja. Na ovaj način koristi se 77% genetskog potencijala šećerne repe, za razliku od 44% u uslovima prirodnog vodnog režima zemljišta. Navodnjavanjem većim normama prinos se smanjuje