Aim. To study the impact of an alternative organic-mineral fertilization on the photosynthetic and biological productivity of sugar beet under modernizing it with the latest agrochemical means. Меthods. Short-term field and analytical. Results. The results of research on the impact of an alternative organic-mineral fertilization with different saturation with the latest agrochemicals on the photosynthetic and biological productivity of sugar beets are presented. It was established that the development of the leaf surface, the content of chlorophyll in the leaves, the photosynthetic and biological productivity of sugar beet increased significantly when foliar fertilizing with agrochemicals was carried out against the background of the organic-mineral fertilization. Conclusions. Application of N30 + «Folcrop Combi» + «Folcrop Amin» for foliar fertilization against the background of 5 t/ha of straw + P90K90 under plowing + N90 under pre-sowing cultivation formed the maximum development of the leaf surface: in July – 1920 cm2/plant, in August – 2566, in September – 1790 cm2/plant. The specified fertilization ensured the maximum content of chlorophyll in leaves in July – 2.01%, August – 1.94%, September – 1.80%. The net productivity of photosynthesis in sugar beet plants in August with the application of straw and mineral fertilizers increased compared to the control without fertilizers – in 1.60 times, with additional foliar fertilization – in 1.77-1.93 times. The most intensive processes of photosynthesis occurred with the combined application of 5 t/ha of straw + P90K90 under plowing + N90 under pre-sowing cultivation + «Folcrop Combi» + «Folcrop Amin» − the net productivity of photosynthesis was 11.08 g/m2 per day. The use of a modernized organic-mineral fertilization (5 t/ha of straw + P90K90 under plowing + N90 undern pre-sowing cultivation + N30 + «Folcrop Combi» + «Folcrop Amin») ensured the highest biological productivity of sugar beet: yield of roots – 60.3 t/ha, sugar harvest – 10.37 with exceeding the control without fertilizers – by 19.1 and 3.20 t/ha.