THE INFLUENCE OF SOME NITROGEN AND POTASSIUM FERTILIZER RATES ON OILSEED WINTER RAPE YIELD AND SOME QUALITY INDICATORS ON A KASTANOZEM PUBLISHEDAna Maria DODOCIOIU, Stefan POPESCU, Andreea Maria NICOLAE, Romulus MOCANU, Marian DOBRE
Within 2008-2011 period there have been carried out experiments on typical kastanezem fromCentral Norther Plateau of Dobrogea with oilseed winter rape crop including two experimental factors:-the A factor, the potassium fertilizer rate with two graduations: a1=K 0 ; a2=K 50 ; a3=K 110 ;- the B factor,the nitrogen fertilizer rate with five graduations: b1 = N 0 ; b2 = N 16 ; b3 = N 50 ; b4 = N 100 ; b5 = N 150. Fromthe combination of these two factors there resulted 15 variants. The yields obtained, on average, duringthree years of experimentation (2008-2011) have indicated the fact that the oilseed winter rape recordedvery good feedback to nitrogen fertilization and the applying of potassium strenghtened the nitrogeninfluence by helping developing a good root system that capitalise the nitrogen much better. This way, onK 100 fertilizer background the yield outputs have been statistically proven with N 100 (1,362 kg/ha),respectivelly, N 150 (1,875 kg/ha), the yield increase being of 37.59%. The applying of potassium hasdetermined significant outputs of the oil content of the yield per hectare with K 100 , this increase being of24.03%. It has increased from 40.75% with K0 to 42.01% with K100. The nitrogen has negativelyinfluenced the oil content, it decreased from 42.71% to 40.75%. The highest value of the hectolitricalmass and the mass of a thousand grains have been reported with K 100 N 150 rate (67.41 kg/hl and,respectivelly, 3.62 g). The applying of a high rate of potassium (K 100 ), on average during three years ofexperimentation has decreased the protein content from 23.62% to 22.88%, yet the differentiatedapplying of nitrogen (N 100 -N 150 ) has determined the increase of this parameter from 21.78% to 25.37%.This way, on K 50 and K100 fertilizer background the protein content has increased as compared withthe control treatment without nitrogen by 1.06 – 16.47% and, respectively, by 0.88 – 14.74%.Statistically, there were recorded differences when 50 and 100 kg N/ha were applied.
oilseed rape, kastanozem, potassium, nitrogen, protein content oil content