THE IMPACT OF SOIL TILLAGE AND FORECROP ON AGRICULTURAL PHYSICAL PARAMETERS AND CROP YIELD OF SPRING WHEAT IN THE NORTHERN PART OF KAZAKHSTAN

The research was carried out on the carbonate black soil of Akmola region in two five-field crop rotations in 2010-2016. The scheme of the experiment included the following ways of soil tillage: deep flat-cutting DF-3-5 (at a depth of 25-27 cm), surface flat-cutting KPSSH-9 (at 10-12 cm), para ploughing SHR-4.5 (at 25-27 cm) and No-till . The researchers observed the highest moisture reserves in the soil layer of 0-100 cm for 7 years in the variants with deep flat-cutting tillage and para ploughing: 115.6 and 112.6 on steam, 108.5 and 105.4 mm on pea. The lowest amount of moisture (80.4 mm) was observed in No-till treatment. The density of the arable soil layer of the southern carbonate black soil before spring wheat sowing corresponded to the appropriate values. When experiencing mechanical treatment, the density of arable layer varied from 1.23 to 1.26 g/cm3; in No-till variant it was 1.31 g/cm3. The concentration of valuables in the variants with deep and surface mechanical tillage varied within 70.9-75.6%, when No-till method was applied, the parameter reduced to 64.5 - 61.5%. The yields of spring wheat sown on steam varied within 1.70 - 1.82 t/ha and did not depend on the soil tillage., Regardless the soil treatment, cultivation of wheat after peas reduced grain harvest on 0.12 - 0.27 t/ha in comparison with steam variant. The authors didn’t observe reliable differences in the crop yield between the first and second crops of grain-steamed crop rotation when applying mechanical soil tillage. In the No-till system there was a reliable decrease in wheat yield on 0.24 t/ha.