The problem of soil protection from erosion is relevant for many countries in the arid zone of the world, including the territory of Uzbekistan. In the republic, the main arrays of crops are located on rainfed lands, where the crop is created only due to moisture in precipitation. The amount of porosity (duty cycle) of soils is determined mainly by specific and bulk mass, mechanical composition, and humus content. Porosity of soils decreases from unwashed soils to washed away and down the profile. In the arable horizons of unwashed rainfed soils, it is 52%, washed out - 47.49%. Deeper in the profile, in horizons transitional to soil, due to a sharp increase in density and a decrease in the humus content in all soils, regardless of erosion, Porosity sharply drops to 48-50%. Thus, with a small bulk mass, the overall porosity of rainfed typical serozems is generally satisfactory, since it provides good soil aeration and the use of precipitation, only on highly washed away soils the porosity decreases markedly and the absorption of precipitation is slightly worsened.