NITROGEN FERTILIZATION EFFECTS ON THE YIELD QUANTITY AND QUALITY OF WINTER WHEAT

摘要

Agriculture has traditionally an important role in Hungarian economy and rural development. About 70% of Hungary's total territory is under agricultural land use, and 50% is the arable land. Hungarian crop production is cereal oriented (65-68% of arable land) because of agroecological conditions, production traditions, market-utilization and -demand. Our normal and long-term, small and big plots experiments covered to study the effects of agroecological conditions (cropyears, soils), the aspects of variety-selection (genetic-pool testing) and individual and interactive effects of different agrotechnical elements on the yield, yield-stability and -quality of wheat production. To build up sustainable, environmental-friendly fertilization-system of wheat, we have to take not only climatic, soil conditions (site-specific aspects) into consideration, but we have to know the biological responses of different genotypes (variety-specific aspects). The fertilizer response types of winter wheat varieties could be defined by making algorithms of our long-term experimental data. According to our results the genotypes of wheat could be classified into 4 groups, regarding nutrient utilization and fertilizer response: type A-modern genotype; type B-extensive genotype; type C-intensive genotype; type D-out-of-date genotype. Our long-term experiments proved that the soil water reservoir (especially on such soil types which could be characterized by excellent water husbandry parameters) also has an important role in the water supply of winter wheat besides the quantity and distribution of precipitation in the vegetation period. In our long-term experiment the optimum N-dose (+PK) varied depending on the cropyear (water supply in vegetation period and winter period too) and genotypes (variety-specific fertilization). The optimum N-doses ranged 60-120 kg·ha~(-1) (+PK) depending on years and variety. Over the optimum N-dose some NO_3-N residues remained in the soil which accumulated year by year. The appropriate fertilization could effectively modify not only the yield quantity but quality as well. Our long-term experimental results proved that the fertilization (mainly N and harmonized PK) could strongly increase the wet gluten content and averagely the farinograph indexes and slightly the falling number. Our result proved that the changes of quality parameters were variety-specific. Our experimental data proved that the basic element of agronomically and economically efficient wheat production is the appropriate variety-selection (to take into consideration ecological conditions and management level) and to use the integrated crop models of traditional and new, precision growing elements.