THE EFFECT OF GROWING METHODS, SITES AND YEARS ON THE NUTRIENT CONTENT AND BAKING QUALITY OF WINTER-WHEAT GRAIN

Results of three series of polyfactorial field experiments conducted w ith winter wheat at three different sites were analyzed from the stand point of various forecrops and increased nitrogen doses effects. Compl ex evaluation made possible to determine following descending order of factors decisive for individual nutrient content and selected indices of baking quality of winter wheat grain: nitrogen - site, fertilizing , forecrop, year; phosphorus - year, site, fertilizing, forecrop; pota ssium - site, forecrop, year, fertilizing; calcium, magnesium - year, site, forecrop, fertilizing; gluten content - year (57%), sire (28%), nitrogen fertilizing (15%); gluten index - site (95%), year (4%), nitr ogen fertilizing (1%); falling number - year (68%), site (28%), nitrog en fertilizing (4%). In comparison with less fertile soil (cambisol) h igher nitrogen contents in grain were found on more fertile soils (luv isol) after leguminous crops as forecrops. The increased nitrogen cont ent in grain after nitrogen fertilizing was significantly higher on le ss fertile soil, but the level of nitrogen content in grain on more fe rtile soils was not reached. The gluten content, gluten index and fall ing number were practically not affected by nitrogen fertilizing, with the exception of minimal changes in gluten content only. Nutritive qu ality and technological quality of wheat grain are determined, besides by the variety, by on-site factors and year to a greater extent than by cultural practices. The differences between the sites and years can not be blurred even by intensive fertilizing.