The work purpose is the assessment of efficien-cy, fodder value and nitrogen mobilizing ability of fodder crops in the leached chernozyom of Krasno-yarsk forest-steppe. Organic forms of nitrogen were determined according to Cornfield, ammonium (N-NH4), colorimetrically with Nessler's reactant; nitro-gen of microbic biomass (Nmb) was determined by regidratation method. In years with favorable mois-tening, despite long vegetation (13 years), galega showed high efficiency. Its productivity and pa-rameters of the quality significantly surpassed standard option of fodder culture of the region, i.e. alfalfa. In comparison with one-year crops of payza and annual clover eastern galega significantly con-ceded to them in productivity and the main fodder characteristics in adverse hydrothermal conditions. Dynamics of fractions of nitrogen under fodder herbs was shown. In their pedocenosis the favora-ble fund of organic nitrogen was formed, multidirec-tional dynamics of ammonium nitrogen was re-vealed. Ammonificated and immobilized processes in the soil under fodder herbs had interfaced dy-namics. By the results of research the following conclusions were drawn: 1) in comparison with one-year crops of payza and annual clover galega significantly conceded to them on productivity and the main fodder characteristics in adverse hydro-thermal conditions; 2) hydrothermal conditions sig-nificantly influenced the concentration of Nmg; 3) the maximum of nitrogen of microbes’ biomass were noted in the soil of phytocenosis of annual clover (2014) and alfalfa. (2015); 4) essential dependenc-es between nitrogen forms in the soil and productiv-ity of herbs were not revealed, except for phytocenosis of alfalfa.