Productivity of seed potatoes with local application of phosphorous and potassium fertilisers

Ukraine occupies a leading position in potato production, being one of the top three producing countries and ranks second in the world in terms of potato consumption per capita, second only to Belarus – 139 kg per year per 1 person, with a global average of approximately 33 kg/person/year. According to the UСAB, in recent years, the area under potatoes has increased by 2.7% to 1,325 thousand hectares. However, the average yield over the past three years was at the level of 15.8 t/ha. In some advanced farms in Ukraine, the yield reaches 30-40 t/ha due to the introduction of scientific findings into production. However, in general, in Ukraine, the potential for the economic productivity of potatoes now remains unused to the full extent. Potato plants are demanding in terms of the availability of nutrients in the soil. They should be in an accessible form and in sufficient quantity. This is largely due to the biological characteristics of potatoes. The effectiveness of mineral fertilisers depends on the methods and quality of their application. The conventional method of fertilisation involves spreading fertilisers on the surface and then covering them with soil. As a result of the uneven placement of fertiliser granules in the soil layer, nutrients transition to a form inaccessible to plants, which leads to uneven development and maturation of tubers. Therefore, one of the ways to improve potato nutrition, reduce nutrient losses, and obtain high, stable crop yields is to apply mineral fertilisers locally to the root system of plants. Local application of phosphorus leads to its better availability throughout the growing season, which ensures accelerated growth and development of roots and shoots, and the formation of an optimal number of tubers. Local placement of potassium improves its availability and provides enhanced synthesis and transport of carbohydrates in plants, increases the absorption of moisture and nutrients by roots, strengthens their resistance to diseases, and improves the quality of tubers. The purpose was to examine the efficiency of using phosphorus and potassium in various methods and norms of fertiliser application and to establish the effect on the productivity of seed potatoes. The studies were conducted in the field experiment by the Department of Agricultural Chemistry and Quality of Plant Products named in honour of O.I. Dushechkin of the National University of Life and Environmental Sciences of Ukraine on the territory of Biotech Ltd. (Boryspil district, Kyiv region) during 2019-2020. An early-maturing Tyras variety was chosen for the research. The area of the sown plot was 495 m2, accounting plot – 312 m2. The experiment is repeated four times. The placement of options was systematic. As a result of the experiment, it was identified that local application of phosphorous and potassium fertilisers provided such a level of the yield of potatoes of the Tyras variety, which was not inferior to the option with a spreading method. The yield increase in variants with local application ranged from 0.6 t/ha to 2.9 t/ha, depending on the norm. Application of local fertiliser with the P60K135 norm caused the highest yield of seed potatoes among the variants (33.4 t/ha), and the highest yield of the seed fraction – 31.6 t/ha