00333nam a2200097Ia 4500008004100000082002300041100002300064245011800087260002300205300000700228140113s9999    xx            000 0 und d  a631.416.001.4   L5  a"Robinson, J.B.D."  aThe Soil Nitrogen index and its calibration with crop reference to improve fertilizer efficiency of Arable soils.  a1975bCABcEngland  a53