Abstract: The article elaborates on the possibility of increasing cotton yields by improving the agrophysical, agrochemical and microbiological properties of fallow soils by deep tillage at different depths between rows of cotton grown on irrigated fallow soils in the southern regions of the Republic of Uzbekistan. In variants 4 and 5 of the experiment, an increase in cotton yield was observed as a result of improved agrophysical, agrochemical and microbiological properties of the soil when cotton was cultivated at depths of 26-28 cm and 30-32 cm, respectively. In the experiments, when the cotton row spacing was loosened to a depth of 30-32 cm, the mass volume of the soil in the drive and subsoil layers decreased by 0,02-0,03 g/cm3 , porosity by 2,0-2,1%, water permeability by 100-120 m3 /ha increase in; humus content was higher by 0,004%, nitrogen content was higher by 0,007%, and phosphorus content was higher by 0,006%; As a result of the rapid development of the cotton root system, the efficiency of moisture and nutrient utilization has increased, and an additional 4-5 ts/ha of cotton has been proven to be obtained. The best results are obtained by cultivating cotton at a depth of 30-32 cm between rows. additional yield was obtained.