IMPACT OF MINERAL ELEMENTS AND HUMIC ACIDS ON SPRING WHEAT AND SPRING OILSEED RAPE AGROCENOSES
Keywords:humic acids, silicon, photosynthetic pigments
A study was conducted to assess the influence of mineral elements and humic acids on the amount of photosynthetic pigments in spring wheat and spring oilseed rape leaves. Field experiments were conducted in 2022 from april to september at the VDU Agricultural Academy Test Station. Spring wheat and spring oilseed rape were locally fertilized with different fertilizers. The content of chlorophylls a, b and carotenoids in the green mass of spring wheat and oilseed rape leaves was determined by the spectrophotometric method. Photosynthetic pigments were determined in the Soil and plant nutrition laboratory of the department of Agroecosystems and soil sciences of VDU ŽŪA. The optical density of the samples was measured based on the absorption of light at wavelengths of 440,5 nm, 662 nm, and 644 nm. Plant photosynthesis indicators were determined three times during the plant vegetation (in the spring wheat crop: at tillering, flowering and dairy maturity stages; in the summer oilseed rape crop: at rosette, buttonization and pod formation stages). The yield of summer plants was determined by a small-sized harvester Wintersteiger Delta (Wintersteiger, Austria) with a weighing and moisture detection system. Fertilizers with humic acids and silicon significantly increased the content of chlorophyll a, b and total pigments in spring wheat leaves during flowering and milky maturity stages. The amount of chlorophyll a, b and total pigments in the leaves of summer oilseed rape during the rosette and buttonization stages was significantly higher after the application of fertilizers with humic acids and silicon. After the application of fertilizers with humic acids and silicon, the yield of spring rapeseed was significantly – 1.48 times higher than the yield of spring rapeseed, which was fertilized with fertilizers without humic acids and silicon.