00261nam a2200097Ia 4500008004100000082002000041100002500061245003300086260003600119300000800155140113s9999    xx            000 0 und d  a631(02)   )2.77  a"Sparks, D. L., ed."  aAdvances in Agronomy -vol.77  a2002bAcademic PresscSan Diago  a438