Assessment of natural resource potential of the agroecosystems of Ukraine and the EU countries by phosphorus balance

Aim. To conduct a comparative assessment of the current state and dynamics of phosphorus balance in the agroecosystems of Ukraine and the EU and determine the methods to manage phosphorus flows and restore its funds in the soils. Methods. The methods of the Organization for Economic Cooperation and Development (OECD, 2007) to assess the flows and balance of phosphorus and its use efficiency (PUE) in the crop production subsystems were used (Chowdhury et al., 2021). The initial data were taken from the electronic resources of the State Statistics Service of Ukraine (http://www.ukrstat.gov.ua), Eurostat (https://ec.europa.eu), and State Institution of Soil Protection of Ukraine (https://www.iogu.gov) regarding the inspection of agricultural fields by the results of XI round (2016–2020). The index maps were built in the MS Excel 2021. Results. The gross balance of phosphorus in the agroecosystems of Ukraine and 30 European countries in 1990–2021 was determined. A decrease in the soil potential for phosphorus content, calculated by the indices of phosphorus flows in modern agricultural production, was determined. It was shown that, on average, the amount of phosphorus removed by the economically valuable part of the crop significantly exceeded its entry into the soil with fertilizers. The state of the use of mineral and organic fertilizers in crop production in Ukraine and EU countries was compared. The unbalanced use of soil phosphorus in Ukraine's agroecosystems in 1995–2021 was revealed: the negative phosphorus balance increased from –5.6 to –11.4 kg P/ha/year and the intensive soil load — PUE 139–256%, which is primarily due to a decrease in the use of organic fertilizers from 9.6 to 0.8 kg P/ha/year, and phosphorus mineral fertilizers — from 17.9 to 6.9 kg P/ha/year. The minimal gross P balance (0.6 P/ha/year) established in the EU countries was observed only in 2019. Among the EU countries in 2019, the gross P balance ranged from –5.6 to 6.0 kg P/ha/year. The countries with a negative P balance (2019) include Romania (–5.6 kg P/ha/year), Bulgaria (–5.4), Germany (–4.8), Slovakia (–1.9), Sweden (–1.5), Lithuania (–1.3), Hungary (–0.4) and the Czech Republic (–0.03 kg P/ha/year), the indices of which are lower than those for Ukraine. The PUE in the EU countries (2019) was within the range of 62–167%. In particular, the PUE above 100% was found in Hungary — 103%, Lithuania — 111%, Sweden — 113%, Germany — 126%, Slovakia — 118%, Romania — 152%, and Bulgaria — 167%, which is lower than in Ukraine — 186%. Currently, in Ukraine, the amount of mineral phosphorus applied to the sown area is close to the EU average but 11 times lower than the amount of organic phosphorus applied to the soil. Conclusions. To achieve a deficit-free balance of phosphorus, restore its content in soils, minimize negative environmental impacts, and increase economic benefits, it is advisable to compensate for the removal of phosphorus with the main products not only by applying industrial phosphate mineral and organic fertilizers but also by creating agroecosystems with a high level of phosphorus recycling and using current local phosphorite deposits.