Plant Nutrition Food security and sustainability of agro-ecosystems through basic and applied research - Horst, Walter.; Schenk, M.K.; Bürkert, A.; Claassen, N.; Flessa, H.; Frommer, W.B.; Goldbach, Heiner E.; Olfs, H.-W.; Römheld, V.; Sattelmacher, B.; Schmidhalter, U.; Schubert, S.; et al. (Springer Netherlands : Imprint: Springer, 2001)