TY  - BOOK
AU  - Robinson, J.B.D.
TI  - Soil nitrogen, index and its calibration with crop performance to improve fertilizer efficiency on arable soils
T2  - (Special publication; no. 1)
SN  - 9780851983400
PY  - 1975///
CY  - London
PB  - Commonwealth Agricultural Bureaux
ER  -