Hypothetical framework integrating the main mechanisms involved in the promoting action of rhizospheric humic substances on plant root- and shoot- growth

1. Olaetxea, M.
2. De Hita, D.
3. Garcia, C.A.
4. Fuentes, M.
5. Baigorri, R.
6. Mora, V.
7. Garnica, M.
8. Urrutia, O.
9. Erro, J.
10. Zamarreño, A.M.
11. Berbara, R.L.
12. Garcia-Mina, J.M.