Agronomic response of durum wheat (Triticum durum Desf.) to nitrogen rates in a long-term fertilizing experiment

Abstract

The aim of the study was to analyze the agronomic response of durum wheat during 1990-2014 to nitrogen rates 0, 40, 80, 120 and 160 kg.ha-1. It was found that without N durum wheat realized grain yield of 2.34 t.ha-1. The highest yield was obtained at 120 kg N.ha-1. The partial factor of productivity decreased with the increase of N from 74.7 kg.kg-1 (N 40) to 24.1 kg.kg-1 (N 160). No proven differences were found in the agronomic efficiency for rates of N 40 to N 120 , as the values were 17.0-14.9 kg grain.kg-1. The use of 160 kg N.ha-1 reduced the N agronomic efficiency by 40% compared to N 40. A strong positive correlation was obtained between N rates and yield (r = 0.930*). The strong negative relationship was proven by N and by partial factor productivity and agronomic efficiency.

Keywords

• nitrogen rates
• durum wheat
• efficiency