PL
Podstawą badań było trzyletnie ścisłe doświadczenie polowe przeprowadzone na czarnej ziemi zdegradowanej, klasy bonitacyjnej IIIb, o obojętnym odczynie, bardzo wysokiej zasobności w fosfor i potas oraz niskiej - w siarkę. Doświadczenie realizowano w układzie równoważnych bloków z dwoma czynnikami, w czterech powtórzeniach. Celem badań była ocena interakcji zróżnicowanych dawek azotu (0, 60, 120 i 180 kg N∙ha-1) i siarki (0, 20 i 60 kg S∙ha-1) z uwzględnieniem różnych sposobów jej aplikacji (doglebowo i dolistnie), na wzrost i rozwój od krzewienia do zbioru, roślin rzepaku jarego odmiany Star. Wykazano, że warunki pogodowe w sezonie wegetacyjnym i nawożenie azotem determinowały dynamikę wzrostu roślin. Największe naturalne ubytki roślin w okresie wegetacji stwierdzono na obiektach bez nawożenia azotem i siarką, a aplikacja azotu istotnie ograniczała straty. Nawożenie azotem do dawki 120 kg∙ha-1 istotnie wpływało na wysokość roślin rzepaku. Nie wykazano istotnego wpływu siarki ani jej współdziałania z azotem na badane cechy roślin rzepaku jarego.
EN
Rapeseed is a nitrophilous plant to ensure the right growth and development of which, one must provide high amounts of easily available forms of other nutrients, including sulphur. In Poland facing the increasing-over-the-last-years interest in growing that species and progressing sulphur deficit in soil, there has been launched a three-year strict field experiment with spring rapeseed grown under varied fertilization with nitrogen and sulphur. The field experiment was performed in degraded Phaeozems, IIIb soil valuation class, with pH ranging from 6.5-7.1, a very high richness in phosphorus and potassium, medium - in magnesium, and low - in sulphur. There were set up two variants of the experiment, which differed in the sulphur application methods. In the first one - sulphur was applied pre-sowing (into soil), in the other one - as a top (foliar) fertilizer. Between the experiments there was located a common control, without fertilization. They were set up in the two-factor equivalent blocks design, with four reps. The aim of the research has been to evaluate the effect of varied nitrogen rates (0, 60, 120 and 180 kg N∙ha-1) and sulphur (0, 20 and 60 kg S∙ha-1), considering various methods of its application, on the growth and development until the Star cultivar spring rapeseed plant harvest stage was reached. Nitrogen was applied in a form of ammonium nitrate and sulphur - as sodium sulphate. The research demonstrated that the dynamics of spring rapeseed plant growth was mostly determined by the weather conditions in the growing season. Staring from the end of the rosette formation, in all the research years in the objects intensively fertilized with nitrogen (120 and 180 kg N∙ha-1), the next plant development stages were delayed, as compared with the development stages of the plants non-fertilized with nitrogen or fertilized with the rate of 60 kg N∙ha-1. In the controls (without nitrogen and sulphur fertilization) there were reported the highest natural plant losses during the vegetation period. The application of nitrogen significantly limited the plant losses per area unit, as compared with the control. The spring rapeseed plant height before harvest was conditioned by the weather pattern in the vegetation period. Nitrogen fertilization up to the rate of 120 kg N∙ha-1, unlike sulphur application, increased the value of that character significantly.