The data on a comparative assessment of sideral bare fallow (pea-oat, canola and clover) with pure fertilized and not fertilized at different ways of seal to the soil of fertilizers are presented in the article (plowing on depth of 20-22 cm and a disking on depth of 8-10 cm). A research objective was to establish the influence of different sideral bare fal-lows in comparison with pure bare fallow on productivity of wheat and oats (in an after-effect) at application of various siderats, the ways of their seal to the soil in a corn bare fallow crop rotation and to estimate crop rotations with pure and side-real bare fallows on the production exit. It was re-vealed that in direct action on the first culture after bare fallow in the southeast forest-steppe on gray forest soils of Irkutsk region the best predecessor is sideral clover bare fallow on condition of seal of a siderat a disking in a soil blanket. The way of seal of a siderat in an after-effect had no noticeable im-pact on productivity of oats unlike direct action on wheat. Clover sideral bare fallow influenced the productivity of the first and second culture comes nearer to effect of pure bare fallow as at seal of siderat plowing and disking. From all sideral cul-tures the highest productivity of green material of a siderat was received on average for years of re-searches at pea-oat mix, and the lowest was at colza. The greatest exit of grain with 1 hectare of the crop rotation area both at a plowing of fertiliz-ers, and at their disk seal is provided equally by the pure fertilized bare fallows and clover sideral bare fallow.