The soil nitrogen index and its calibration with crop performance to improve fertilizer efficiency on arable soils
J. B. D. Robinson.
Farnham Royal, Eng : Commonwealth Agricultural Bureaux, 1975.
53 págs. : ilustraciones ; 25 cm.
Serie: Special publication - Commonwealth Bureau of Soils ; nº 1
ISBN: 0851983405
Bibliografía: p. 47-53.