The effectiveness of foliar top dressing of meadow clover (Trifolium pratense L.) with the preparation kelik-potassiumsilicon on different backgrounds of phosphorus-potassium nutrition in the conditions of the Central Non-Chernozem region

To determine the optimal doses of phosphorus-potassium fertilizers for growing meadow clover (Pochinkovets variety) in 2022–2024, a field study was conducted on sod-podzolic medium loamy soil of the Smolensk region (pH 5.4) with a low humus content (2.0 %), increased phosphorus (142–148 m/kg) and medium potassium (98–105 mg/kg). The effect of various combinations of phosphorus-potassium fertilizers and foliar top dressing of plants with kelik-K-Si on yield, the content of crude protein, phosphorus and potassium in hay was To determine the optimal doses of phosphorus-potassium fertilizers for growing meadow clover (Pochinkovets variety) in 2022–2024, a field study was conducted on sod-podzolic medium loamy soil of the Smolensk region (pH 5.4) with a low humus content (2.0 %), increased phosphorus (142–148 m/kg) and medium potassium (98–105 mg/kg). The effect of various combinations of phosphorus-potassium fertilizers and foliar top dressing of plants with kelik-K-Si on yield, the content of crude protein, phosphorus and potassium in hay was studied. The maximum yield was achieved at a dose of R48K48 in 2022 (GTK 1.55) and in 2024 (GTK 1.80) – 20.0 and 12.5 t/ha of hay, respectively. In the dry year of 2023, the best indicators (8.3 t/ha) were observed in the R80K32 variant. Foliar top dressing of clover with a 1% solution of the drug significantly increased the yield. The maximum crude protein content (13.0–14.0 %) was observed in variants with an increased dose of phosphorus and its combination with potassium (P48, P48K48 and P80K32). The phosphorus and potassium content in hay corresponded to zootechnical standards and remained stable due to genetically fixed mechanisms of regulation of the chemical composition of plants. On average, 1 ton of clover hay contains Pochinkovets: 12.7–12.9 c of crude protein, 4.8–5.3 kg of P2O5 and 14.6–14.9 kg of K2O. These values can be taken as removal standards for meadow clover in the development of varietal agricultural machinery on sod-podzolic soils of the Smolensk region and to assess the fodder advantages of hay. According to the totality of agronomic and economic efficiency indicators, the best options are R48K48 and R48K48+ foliar top dressing with kelik-K-Si. Non-root top dressing can achieve a noticeable effect, minimize environmental risks and can be easily integrated into the existing system of agrotechnical measures.