Аңдатпа
The experiments were performed within a 20-year-long period in six variants, including the cultivation of cotton monoculture in four crop rotations without fertilizers and with application of mineral fertilizers and manure. The content of humus, nitrogen, phosphorus, potassium, calcium, magnesium, and sodium in the plow layer and in the entire soil profile (to a depth of 150 cm) was the highest in the cotton–lucerne–cereal crop rotation with application of mineral and organic fertilizers. The productivity of raw cotton in this variant of the experiment was 3.17 t/ha in the first decade and 2.56 t/ha in the second decade.