Effect of inoculation with Azotobacter chroococcum on nitrogenase activity of Zea mays roots grown in agricultural soils under aseptic and non-sterile conditions

1. Martinez Toledo, M.V.
2. Gonzalez-Lopez, J.
3. de la Rubia, T.
4. Moreno, J.
5. Ramos-Cormenzana, A.