Uticaj đubrenja na dinamiku mineralnog azota u zemljištu pri gajenju inbred linija kukuruza

Abstract

Ispitivanja su obavljena na oglednom polju Instituta za kukuruz "Zemun Polje" tokom 1998. i 1999, na zemljištu tipa semiglejno-karbonatni černozem. U ogledu su korišćene tri inbred linije kukuruza (L1, L2 i L3) različitih grupa zrenja (FAO 300, 500 i 700) i primenjeno je pet varijanti đubrenja: I - kontrola bez primene đubriva; II - 60 kg P2O5/K2O ha-1, 60 kg N ha-1; III - 60 kg P2O5/K2O ha-1, đubrenje azotom na bazi N-min metode (sa dopunom do 120 kg ha-1); IV - 60 kg P2O5/K2O ha-1, 120 kg N ha-1; V - 60 kg P2O5/K2O ha-1, 180 kg N ha-1. Dinamika mineralnog azota u zemljištu zavisila je od meteoroloških uslova u toku izvođenja eksperimenta. Sadržaj mineralnog azota u zemljištu u fazi svilanja i na kraju vegetacije bio je različit kod ispitivanih inbred linija kukuruza, i zavisio je od primenjenih doza azotnog đubriva. Sadržaj nitratnog azota u zemljištu u obe godine ispitivanja bio je znatno veći u odnosu na sadržaj amonijačnog azota, kod sva tri genotipa i na svim tretmanima đubrenja.

Three maize inbred lines (L1, L2 and L3) of different maturity groups (FAO 300, 500 and 700) were studied in the trial with five fertilising variants: I - control without fertilisers; II - 60 kg P2O5/K2O ha-1, 60 kg N ha-1; III - 60 kg P2O5/K2O ha-1, fertilising with nitrogen according to the N-min method (with the addition up to 120 kg ha-1); IV - 60 kg P2O5/K2O ha-1, 120 kg N ha-1; V - 60 kg P2O5/K2O ha-1, 180 kg N ha-1. The objective of the present study was to determine the dynamics of nitrate and ammonium nitrogen in the course of growing maize inbred lines on semi-gley calcareous chernozem under agroecological conditions of the Zemun field in order to optimise and rationalise the application of N-fertilisers in seed maize. Dynamics of mineral nitrogen in the soil depended on meteorological conditions prevailing during the performance of the experiment. The mineral nitrogen content in the soil varied over genotypes and applied rates of nitrogen fertilisers. The highest mineral nitrogen content in the soil (to the depth of 0-120 cm) in the silking stage in both years of investigation was determined in the soil under the inbred line L1, as well as, in the treatment with the application of 180 kg N ha-1 (V). The corresponding values at the end of the growing season were also detected in the soil under the inbred line L1. In 1998 the highest amount of mineral nitrogen in the soil was estimated in the fertilising variant III (N-min methods), while in 1999 the corresponding values were determined in the fertilising variant V (120 kg N ha-1).