A range of crops – sugar beet, sunflower, cabbage, flax – after long-term cultivation in the same field (a monoculture) significantly reduces productivity. This phenomenon is well known in agriculture as soil depletion. A number of factors, which deteriorate soil properties, exists: one-sided phosphorus depletion, potassium depletion of the soil, as well as reduced level of microelements, soil contamination of pathogenic infection, root exudates of plants themselves. Application of soil conditioners weakens and then eliminates the harmful effect on plants and soil depletion, and the conditioners help to do it much faster than the traditional method of crop rotation. The crop rotation is based on the natural self-cleaning soil capacity caused by the activities of the soil microfauna. To speed up the process of purification of the soil, it is necessary to increase the soil biological activity by application of peloids (including joint application with manure, fertilizers and green-manures). This way the crop rotation period, for example, for sunflower or sugar beet, is not 5-6 years, but 3-4 years approximately.