INFLUENCE OF SEEDBED PREPARATION ON SUGAR BEET GERMINATION ON CRUST LIABLE SOILS IN CROATIA

U periodu kroz tri godine (1983-1985) istraživane su različite varijante pripreme tla za sjetvu šećerne repe. Nakon dubokog jesenjeg oranja u jednoj varijanti tlo je u jesen tanjurano odmah nakon dubokog jesenjeg oranja. U drugoj varijanti tanjuranje je vršeno u proljeće. U obje varijante ispitivano je šest načina pripreme tla za sjetvu i to: 1. Tanjuranje u proljece +sjetvospremač; 2. Tanjuranje u proljeće + sjetvospremač + valjanje; 3. Tanjuranje u proljeće + sjetvospremač + valjanje iza sjetve; 4. Dva prohoda sjetvospremačem + valjanje; 5. Jedan prohod sjetvospremačem + valjanje; 6. Jedan prohod sjetvospremačem + valjanje + valjanje iza sjetve. lspitivana je brzina nicanja, % nicanja, prirod i digestija. U varijantama bez tanjuranja iza oranja u jesen, nicanje je trajalo od 14,11 do 9,54 dana, % nicanja se kretao od 62,27 do 73,43 %, prirod od 32641 do 40370 kg/ha, digestija od 14,28 do 16,28 %. Daleko bolji rezultati su dobiveni kada je u jesen iza dubokog oranja odmah provedeno tanjuranje. Nicanje je trajalo od 11,72 do 6,96 dana, postotak nicanja od 70,63 do 82,99 %, prirod od 38985 do 40677 kg/ha i digestija od 15,06 do 16,92%. Bolji rezultati za sva ispitivana svojstva dobiveni su u varijantama gdje je uključeno valjanje, a najbolji u varijanti proljeće priprema tla za sjetvu jedan prohod sjetvospremačem + valjanje + valjanje iza sjetve.Different variants of soil preparation for sugar beet sowing were researched in the three year period (1983-1985). After a deep autumn ploughing in one variant the soil was not disk harrowed, while in the other variant disking was done imediately after autumn ploughing. In both variants six different ways of soil preparation for sowing were studied: 1. Disk harrowing in spring + seed bed preparation machine; 2. Disk harowing in spring + seedbed preparation machine + rolling; 3. Disk harrowing in spring + seedbed preparation machine + rolling + rolling after sowing; 4. Two passes of seedbed preparation machine; 5. One pass of seedbed preparation machine; 6. One pass of seedbed preparation machine + rolling after sowing. Speed of germination, seedling emergence rate, yield and digestion were studied. In the variant with no disk harrowing after autumn ploughing germination lasted from 14.1 to 9.5 days, seedling emergence rate ranged from 62.6 to 73 .4%, yield was from 32641 to 40370 kg/ha, digestion was from 14.2 to 16.2%. Far better results were obtained when after deep ploughing in autumn, the soil was immediately disk harrowed. Germination lasted from 11.7 to 6.9 days, seedling emergence rate was from 70.6 to 82.9%, yield was from 38985to 48677 kg/ha, and digestion was from 15.0 to 16.9%. Better results for all the properties were obtained in variants where rolling was included, and the best results were obtained in variant with disk harrowing in autumn after deep plouing and in spring with one pass of seedbed preparation machine + rolling + rolling after sowing