Improvements of Durum Wheat Main Crop in Weed Control, Productivity and Grain Quality through the Inclusion of FenuGreek and Clover as Companion Plants: Effect of N FertilizaTion Regime

Assessing the performance of legume species as companion plants is a prerequisite for promoting a low chemical-input durum wheat production system. This study aims to evaluate fenugreek (IC-Fen), clover (IC-Clo) and their mixture (IC-Mix) performances on weed control, productivity, and grain quality of durum wheat main crop under different N fertilization regimes, as compared to durum wheat alone with (SC-H) and without (SC-NH) herbicide. On-field experimentations were carried out in humid and semi-arid conditions. Results showed that legumes offer significant advantages in terms of weed control, soil moisture conservation, productivity, and grain quality for durum wheat cash crops. Results explain that these benefits depend on the legume part and the adopted N fertilization regime. Most significant improvements occurred with the IC-Mix under unfertilized conditions (N0) and relatively low and late N regimes (N1 and N2) where, for example, the partial land equivalent ratio of durum wheat grain yield (PLER) reached 1.25 compared to the SC-NH, with no need to sort the raw grain product (legumes seeds not exceeding 4.3%). Our study illustrates that under low and late N-fertilization condition using promising legumes species combinations result in the improvement of N fertilizer land-use efficiency and hence help to reduce N-fertilization inputs.