Foliar Fertilization Enhances Oil Flax Yield and Quality in Semi-arid Rainfed Zones

The effectiveness of micronutrients, complex fertilizers with chelated trace elements, and biofertilizers in oil flax cultivation under rainfed conditions in southeastern Kazakhstan remains underexplored.This study aimed to evaluate the impact of foliar fertilization using tank mixes of macro-and micronutrients, complex fertilizers (brands: 13-40-13, 12-12-36, 3-11-38), and the biofertilizer Terra Sorb Complex on the productivity and seed quality of oil flax.Field experiments were conducted on light chestnut soils in the Almaty region during favorable weather conditions with adequate soil moisture and moderate temperatures.Results showed that treatments involving four foliar applications of a tank mix containing MACRO+MICRO elements and NPK fertilizers with chelated elements significantly increased seed count per capsule by 2.1seeds compared to the control.The highest 1000-seed weight (7.2g) was achieved with three or four foliar applications of macro-and micronutrient tank mixes or complex fertilizers with chelated elements, combined with pre-sowing biofertilizer treatment.The maximum seed yield (0.89t/ha) was observed with four foliar applications of MACRO+MICRO elements or NPK fertilizers with chelated elements, representing a 19.2% increase over the control.Additionally, fat content in seeds reached 42.0%, and protein content peaked at 28.4% with foliar treatments.These findings highlight the potential of foliar fertilization to enhance oil flax productivity and seed quality under rainfed conditions.