Productivity and Quality of Durum Wheat (Triticum Durum Desf.) at Increasing Rates Of Nitrogen Fertilization Under Long-Term Accumulation Of Nutrients In Pelic Vertisols

In a stationary fertilizing field trial, initiated in 1966 at the Institute of Feld Crops – Chirpan, Bulgaria, the influence of different rates of a nitrogen fertilizer on the productivity and quality of durum wheat (Triticum durum Desf.) have been investigated. As a result of long-term mineral fertilization data for grain yield have been reported. The physical grain properties and some technological qualities have been determined. In the first year of the study grain yield was generally lower compared to 2015, which was better provided with precipitation. The reaction of durum wheat to the increased rates of the nitrogen fertilizer however is different during the two years. Differences in qualitative traits both depending on weather conditions and on changes in the level of nitrogen fertilization have been recorded.