Land resources were and continue to be one of the main natural resources of any state, the rational use of which depends on its food security, political stability and economic independence. The reformation of the Russian agroindustrial complex in the 90-ies of XX century, due to the transition to market relations, led to the fact that significant areas of arable land have been transferred to the country’s deposits. However, now to eliminate the negative phenomena that have arisen in agriculture, it is necessary to involve previously abandoned lands in the circulation, which are often in poor phytosanitary and cultural-technical condition. Researches on studying of influence of a sideration on optimization of a phytosanitary condition of agrocnosis and the yield of winter rye on sod-podzolic soil of the Eastern part of the Volga-Vyatka zone in the development of fallow lands are conducted. The effectiveness of the use of sideration is revealed. By cultivating of a winter rye on a green manure fallow the phytosanitary condition of crops improves and grain yield significantly increases. Accounting of a contamination of winter rye crops showed that the use of sideration promotes weed control. Preliminary sideration of a fallow land and the subsequent cultivation of winter rye on a green manure fallow reduced contamination of a culture agrocnosis at 18.0-20.0% in comparison with the cultivation on occupy fallow and 11.2-12.2 % – on a fallow land. Winter rye cultivated on a green manure fallow, in comparison with the cultivation on occupy fallow, was exposed less to diseases. The development and distribution of snow mold was lower on 20.0% and 6.1%, root rot – 16.7-17.8 and 13.7 to 15.3% respectively, and the development of Helminthosporium and Septoria blotch – 3.5-11.2 and the 38.4-46.2 % and the spread, respectively, 10.8-13.7 and 24.3-30.8 %, depending on the phenological phases of development and growth of winter rye. The grain yield of winter rye in the cultivation on a green manure fallow was 2.72 t/ha, which 830 kg/ha are more than control variant and on 730 kg/ha in comparison with the placement of a fallow land.