The Effect of Fertilization with Organic and Mineral Fertilizers on Yield and Growth Parameters of Sweet Corn

V SV delu Slovenije smo v letu 2008 proučevali vpliv gnojenja sladke koruze (Zea mays L. saccharata Sturt.) z organskimi (bučne pogače in digestat) in mineralnimi (KAN in Entec 26) gnojili s štirimi različnimi ciljnimi vrednostmi Nmin (70, 120, 170 in 220 N ha-1). Raziskovali smo vsebnost NO3-N in vitamina C v steblu in zrnih sladke koruze, morfološke lastnosti sladke koruze ob spravilu, ostanke dušika ob spravilu ter skupni in tržni pridelek. Odmerki N statistično vplivajo na vitamin C v zrnju ter na nitrate v zrnju in steblu. Gnojilo vpliva samo na nitrate v zrnju. Bučne pogače dosegajo statistično značilno enake ali višje vrednosti z mineralnim gnojilom (KAN, Entec 26) pri višini sladke koruze, širini in dolžini listov, številu vrst na storžu in dolžini storža ter skupnem in tržnem pridelku. Gnojenje z večjim odmerkom dušika daje večji pridelek sladke koruze, čeprav se najvišja odmerka (ciljna vrednost 170 in 220 kg N ha-1) statistično ne razlikujeta. Pri gnojenju z bučnimi pogačami so doseženi dobri rezultati tudi z manjšimi odmerki N ha-1. S ciljno vrednostjo 70 kg N ha-1 smo z bučnimi pogačami dosegli višji pridelek od ostalih gnojili (digestat, KAN in Entec 26) pri ciljni vrednosti 120 kg N ha-1, oziroma z digestatom pri ciljni vrednosti 170 in 220 kg N ha-1. Z bučnimi pogačami je bil gnojen najvišji skupni (15388 kg ha-1) in tržni pridelek (12953 kg ha-1).In 2008, in the northeastern part of Slovenia, we studied the effect of fertilization of sweet corn (Zea mays L. saccharata Sturt.) with organic (pumpkin cakes and pig manure digestate) and mineral (CAN 27 and ENTEC®26) fertilizers with four different N-target values (70, 120, 170 and 220 kg N ha-1), on the content of NO3-N and vitamin C in the stalk and grains of sweet corn, on the morphological characteristics of sweet corn at harvest, on the residues of nitrogen at harvest and on the total and marketable yield. The N-rates statistically affect the level of vitamin C in grains and the level of nitrates in the grains and stalk, while fertilizers only affect the nitrate in grains. Pumpkin cakes statistically achieve equal or higher values than mineral fertilizers (CAN 27, ENTEC®26) when it comes to the height of the sweet corn, width and height of the leaves, number of rows on the cone or length of the cone and total and marketable yield. Fertilization with higher N-rates gives a higher yield of sweet corn, although the highest doses (170 and 220 kg N ha-1) do not differ statistically. In fertilization with pumpkin cakes, good results have been achieved even with lower N-rates, because with pumpkin cakes at target value of 70 kg N ha-1, we achieved a higher yield than with other fertilizers (pig manure digestate, CAN 27 and ENTEC®26) at target value of 120 kg N ha-1, or with pig manure digestate at target values of 170 and 220 kg N ha-1. The highest total (15388 kg ha-1) and marketable yield (12953 kg ha-1) was fertilized with pumpkin cakes