TY JOUR TI SPECIFIC MATERIAL CAPACITY OF WHEEL TRACTORS WHEN BALLASTING FOR THE TILLAGE TECHNOLOGIES KW algorithm KW ballasting KW material capacity KW models KW nomogram KW technology KW specific weight JO Bulletin of KSAU AU Selivanov, N.I. AU Makeeva, Y.N. PY 2015 IS PB Krasnoyarsk State Agrarian University