Influence of lignin mixing ratio of Melia azedarach L. with some fertilizers on plant height, number of leaves and leaf area characteristics of Olea europea L. seedlings (arbequina cultivar)

The research was carried out in two stages: the first was conducted in the chemistry laboratory of the Agricultural Technical College, during which the process of extracting lignin from the trees of Melia azedarach L.. The second stages was conducted in one of the olive fields in the Nineveh forest nursery of the Department of Nineveh agriculture and combating desertification for the season 2022-2021 to see the effect of processing lignin extract on improving fertilizer efficiency and its impact on the growth and development of olive seedlings The experiment involved three factors: The first factor is like adding two levels of lignin (with, without lignin) while the second factor includes three types of fertilizer (NPK, urea, urea 50%+NPK 50%) and four levels of mixing lignin with fertilizer (0,10,%,15%,25%). The research was carried out as a factorial experiment according to the Randomized Complete Block Design (RCBD). The results of the research showed that fertilizing with lignin has a significant effect on vegetative growth qualities (plant height, number of leaves, leaf area), especially the concentration of 25 g/l−1, and foliar spraying with compound fertilizer (NPK) at a concentration of 129 g.l−1 for a significant increase in plant height, urea fertilizer treatment had no significant effect on the quality of leaf count and leaf area, while fertilizer treatment (NPK 50%+Urea 50%)showed significant differences in plant height, in most of the qualities studied, Especially the concentration 69.5 g.l−1, while the interventions and especially the tripartite between the coefficients of the study showed the occurrence of significant effects of different concentrations in all the qualities studied, resulting in positive effects on the seedlings of olive trees, resulting in increased activity and growth stimulation of these seedlings throughout the duration of the research.