Productivity of spring wheat depending on methods of the basic soil tillage and fertilizer systems in the Precarpathian conditions

The research results of the influence of the basic soil tillage and fertilizer system on the fertility of soddy-podzolic soils and the yielding capacity of spring wheat in short-term rotation in the conditions of the Precarpathian region are presented. The research was carried out in 2016‒2018 on the fields of the farm “Fortuna” in the village Negivtsi of Kalush district of Ivano-Frankivsk region. The soil of the experimental plot is soddy-podzolic. It was established that the application of organic fertilizers obtained at the outlet of biogas plants at organic and organomineral fertilizer systems and methods of basic soil tillage positively influenced on the structurization of soddy-podzolic soils in the technology of spring wheat growing. The most agronomically valuable aggregates (0.25‒10.00 mm) were in the variant of surface soil tillage for the organomineral fertilizer system at sowing time ‒ 62.4%, or by 3.7% more compared with the control and before harvesting of the crop ‒ 61.6%, or by 3.8% more in comparison with control. In the same variant, the coefficient of soil structural properties was the highest ‒ 1.66 at sowing time and 1.60 ‒ before harvesting, or, respectively, by 0.24 and by 0.22 exceeded the index in the control. According to the organomineral system of fertilizer in the variant of surface soil tillage (discing at the depth of 8-10 cm), the soil density at the sowing time of the spring wheat in a layer of 0-10 cm was 1.16 g/cm3, in a layer 10‒20 cm ‒ 1.18 g/cm3, which is by 0.05‒0.06 g/cm3 less than in the control. The total porosity of the soil layer of 0‒10 cm at the organic system of fertilizer in the variant of the surface soil tillage (8‒10 cm) at the sowing time of spring wheat was 53.4%, for organomineral system ‒ 54.2%, which is, respectively, by 4,4% and by 5.2% more control. In the layer of soil 10‒20 cm, it was 52.8% and 53.1% and 4.1 and 4.4% respectively. Before harvesting the crop at the organomineral system of fertilizer, the total porosity in the layer of soil 0‒10 cm was 53.7%, 10‒20 cm ‒ 52.6%, which, respectively, by 5.9% and by 4.6% exceeded control indexes; for the organic fertilizer system they were, respectively, 52.3% and 51.8% and 4.5% and 3.8% respectively. The application of organomineral fertilizers obtained at the outlet of the biogas plant resulted in an increase in yields compared with control, on the average over the years of research by 1.41‒2.43 t/ha. The best yielding capacity indexes were achieved on the variant with surface soil tillage (discing at the depth of 8‒10 cm), according to the organomineral fertilizer system, the yielding capacity of spring wheat was 5.28 t/ha, or by 85.2% more relative to the control. To improve fertility of soddy-podzolic soils of Precakarpathian and increase the yielding capacity of spring wheat in the short-term rotation, resource-saving fertilizer systems with application of organic fertilizers (pig manure obtained at the outlet of biogas plants) and minimum doses of mineral fertilizers for optimal soil tillage systems should be used.