Effect of different sources of N2 on the structure of Mimosa caesalpiniaefolia root nodules

Mimosa caesalpiniaefolia is an N2-fixing tree that grows quickly and is a multipurpose tree. In the nursery, the plant needs the maximization of growth. High levels of combined N2 inhibit nodulation in many legumes. Nodules or some species of trees grow slowly in comparison with grain legumes, and a small amount of N2 can stimulate nodulation shortly after germination. The effect of different sources of N2 on nodule structure and plant growth was studied. Applied nitrate drastically affects the nodule structure, and reduces nodule number and plant growth. Plant growth parameters were clearly superior in the presence of NH4+ and it had no deleterious effect on nodule structure.