Influence of monopotassium phosphate fertilizer on vegetable crops yield and indicators of fruit quality and safety

Research new mineral fertilizer of monopotassium phosphate (MPP) regarding the impact (effects) on biometric indicators, yield, quality and safety of vegetable crops was conducted. We studied the effect of MPP on the growth and development of tomatoes and cucumbers at different rates of use. When using MPP, tomato biometric indicators increased: the height of the plants is 6.7–8.2 cm, stem diameter — by 0.9–1.2 cm, leaf area — by 4.2–9.7 dm2 compared to the control and cucumbers: plant height — by 9.4–41.5 cm, stem diameter — by 0.2–0.5 cm compared to the control. It was established that with foliar feeding of open ground vegetables, an increase in the yield of tomatoes to 48.0–49.2 t/ha and cucumbers to 3.9–4.7 t/ha is observed, compared to the control variant 41.4 and 3.1 t/ha, respectively, and the quality of fruits increases significantly. The content of dry matter, sugar, and vitamin C indicate the quality of the fruits of vegetable crops. The dry matter content of cucumbers was 4.1–4.8%, which is 0.2–0.9% more than in the control. The content of sugar and vitamin C had a similar tendency to increase. If in the control their content was 1.1% and 13.7 mg/kg, then when applying fertilizer the content increased by 0.6–1.5%; of vitamin C — by 11.2–18.2%, respectively. The content of dry matter of tomatoes was 7.3–7.7%, which is 0.8–1.2% more than in the control. The content of sugar, vitamin C, and carotene also increased: in the control, their content was 3.1%, 15.2 mg/kg, and 12.9 mg/kg, when the fertilizer was used, the content increased: sugar by 0.8–1.1%; vitamin C — by 5.9–13.0%; carotene — by 6.2–13.7%, respectively. Fruit acidity increased by 0.23–0.13%. The content of heavy metals (Zn, Cu, Pb, Cd, Ni, Co) in the composition of the МКР does not exceed the maximum permissible concentrations specified in the Ukrainian and European standards. Application of fertilizer taking into account the biologically justified rates of consumption will not lead to a significant change in gross (Zn, Cu, Ni, Co, Pb, Cd, As, Мn, Cr, Hg) and mobile (Zn, Cu, Ni, Co, Pb, Cd) forms of heavy metals in the soil. According to the content of natural radionuclides, monopotassium phosphate corresponds to the current Ukrainian regulatory documents. Agricultural products grown with the use of fertilizer meet hygienic requirements regarding the content of heavy metals (Cu, Zn, Cd, Pb) and are safe for human health.