Due to the systematic utilisation of substantial amounts of phosphorus fertilisers on agricultural crops in crop rotation, the amount of available phosphate compounds increases in the soil. It ensures the maximum increase in crop yields. The study of the phosphate level in Chernozem soils in various agrocenoses is really up-to-date. The gist of our research was to determine the specifics of providing mobile phosphorus in typical Chernozem in field crop rotation, especially in sunflower, varying according to fertilisation systems in the forest-steppe zone of Ukraine. The assessment of mobile phosphorus content was conducted using the Chirikov method, which involves extracting mobile phosphorus compounds from the soil using a solution containing acetic acid (CH3COOH) at a concentration of 0.5 mol dmE−3, with a soil–to–solution ratio of 1:25. Phosphorus was determined with the spectrophotocolorimetric method, which is based on the colour intensity of the phosphorus-molybdenum complex. Our investigations showed that the typical low-humus Chernozems have considerable reservoirs of potentially exploitable phosphorus for plant nourishment. We established that the mineral and organic-mineral fertilisation system leads to a greater use of mobile phosphorus with agricultural crops of crop rotation resulting in the formation of elevated phosphate content in the Chernozem soil. By the end of the second rotation, the organic-mineral fertilisation system variant displayed the greatest concentration of mobile phosphorus within the 0–25 cm soil depth, marking a surge of 15.6 mg kgE−1 compared to the unfertilised variant. In the period of sunflower germination, the content of mobile phosphates increased in the soil layers at depths of 0–25 cm and 25–50 cm in the variant of the mineral fertilisation system on 17.6 and 22.2 mg kgE−1 of soil compared to the alternative without the fertiliser. In the sunflower’s ripening period, the mobile phosphorus concentration in the soil at 0–25 cm depth increased significantly in the variant of organic-mineral fertilisation system by 12.0 mg kgE−1 and mineral fertilisation by 14.7 mg kgE−1 of soil if compared with the variant lacking the fertiliser. In the variant of the mineral fertilisation system, the amount of mobile phosphorus increased in the 0–30 cm soil depth by 18.7 mg kgE−1 of soil in two crop rotations compared to the beginning of the first crop rotation.

Reduced tillage is considered as one of the main tools to save biological diversity; however, it increases pressure of diseases, including wheat leaf blotches. The aim of present study was to clarify the impact of reduced soil tillage on the development of winter wheat leaf blotches in different schemes of crop rotation. The impact of different growing technologies on the severity of winter wheat disease was evaluated in a two-factorial experiment: A – soil tillage system, and B – different combinations of wheat pre-pre-crop and pre-crop (wheat, oilseed rape, barley and faba beans). Diseases were assessed every 10 days approximately and total impact of diseases was evaluated by calculating AUDPC (Area under Diseases Progress Curve). Tan spot, caused by Pyrenophora tritici-repentis was dominated disease over the long period, regardless of meteorological conditions. Development of Septoria leaf blotch was not influenced by neither crop rotation nor soil tillage. The level of tan spot was essentially higher after wheat, regardless of the pre-pre-crop. Reduced soil tillage promoted severity of tan spot. Ploughing mitigated effect of previous crops and differences in tan spot level were insignificant. Despite many positive effects of conservation tillage, increasing of fungicide treatment could be necessary, in conditions, when the tan spot is most devastating and widespread wheat disease.

Reduced tillage is considered as one of the main tools to save biological diversity; however, it increases pressure of diseases, including wheat leaf blotches. The aim of present study was to clarify the impact of reduced soil tillage on the development of winter wheat leaf blotches in different schemes of crop rotation. The impact of different growing technologies on the severity of winter wheat disease was evaluated in a two-factorial experiment: A – soil tillage system, and B – different combinations of wheat pre-pre-crop and pre-crop (wheat, oilseed rape, barley and faba beans). Diseases were assessed every 10 days approximately and total impact of diseases was evaluated by calculating AUDPC (Area under Diseases Progress Curve). Tan spot, caused by Pyrenophora tritici-repentis was dominated disease over the long period, regardless of meteorological conditions. Development of Septoria leaf blotch was not influenced by neither crop rotation nor soil tillage. The level of tan spot was essentially higher after wheat, regardless of the pre-pre-crop. Reduced soil tillage promoted severity of tan spot. Ploughing mitigated effect of previous crops and differences in tan spot level were insignificant. Despite many positive effects of conservation tillage, increasing of fungicide treatment could be necessary, in conditions, when the tan spot is most devastating and widespread wheat disease.