Field experiment was established to evaluate the influence of different fertilization treatments on yield and yield components and quality (proteins, oil, fibre, ash matters) of three soybean varieties Korada, Supra and OAC Vision at the experimental farm Oponice (south–western Slovakia) in 2005-2007. The experimental site belongs to warm and moderate arid climatic region. The average rainfall is 607 mm. The average temperature is 9.5 °C, for the growing season 16.1°C.  The main soil type is loamy Haplic Luvisols on loess. Soybean was growing after winter wheat forecrop each year. The conventional tillage practices were used. Mouldboard ploughing in autumn and harrowing in the spring were used. During seedbed preparation preemergent herbicides were applied. The number of plants per m 2 , number of pods per plant, number of seed per pods, TSW and grain yield and yield of aboveground biomass and harvest index were determined. Fertilization treatments were as follows: I. Non-fertilized control, II. LAV 27 % (40 kg.ha -1 of net nutrient of N) in growing stage of first pair of true leaves (BBCH 101), III. Humix komplet (rate 8 l.ha -1 ) applied in growing stage of first pair of true leaves (4 l.ha -1 ) and before flowering (4 l.ha -1 ), IV. DAM 390 (20 kg.ha -1 of net nutrient of N) applied together in growing stage before flowering (BBCH 501). Sowing rate of 0.6 million germinative seeds per hectare, sowing depth 0.05 m, interrow distance 0.125 m were applied. Seeds were inoculated by HiStick preparation. The significantly highest yield of soybean seeds was achieved in year 2005 (3.89 t.ha -1 ). The most productive variety was Korada (4.15 t.ha -1 ). Fertilizer DAM 390 high significantly influenced yield of soybean seeds. Experimental factors (year, variety, fertilization) significantly influenced substance content in soybean seed. There was found out very high indirect dependency between protein content and oil content. No significant direct dependency was noted between oil and fibre content; between oil and ash matter content and between ash matter content and fibre. For agro climatic condition of south-western Slovakia variety Korada and Supra are recommended.

soybean; variety; fertilization; yield; quality

Presentation: oral