TY JOUR TI CHANGING OF THE SOIL FERTILITY PARAMETERS UNDER THE INFLUENCE OF ARTIFICIAL FOREST PLANTATIONS IN SHIRINSKAYASTEPPE KW forest plantations KW virgin land KW soil properties KW difference significance KW spatial variation KW fertility parameters JO Bulletin of KSAU AU Kuular, C.I. AU Sorokina, O.A. PY 2014 IS PB Krasnoyarsk State Agrarian University