TY JOUR TI NITRATE NITROGEN’ INTRAFIELD AND TEMPORAL VARIABILITY IN THE WESTERN SIBERIA FIELDS KW soil heterogeneity KW nitrate nitrogen KW precision farming KW digitization of fields KW fertility of arable land KW fertilizer system KW dark gray forest soil. JO Bulletin of KSAU AU Renev, E.P. AU Eremin, D.I. PY 2021 IS 0 PB Krasnoyarsk State Agrarian University