Influence of Soil Salinity and Fertilizers on Seed Germination and Formation of Vegetative Organs of Sunflowers

The paper focuses on the effect of high concentrations of soil salts on the germination of seeds and vegetative organs of sunflowers. The factors stimulating the development and functional activity of the root system of the plant were identified. The periods and phases of sunflower vegetation were noted, the positive effect of phosphorus and nitrogen fertilizers on the development of the root system and the total root biomass were identified. In the Stavropol region, saline soils occupy about 1.8 million ha. The greatest damage to agriculture in the region, due to a decrease in yield and deterioration of its quality, is caused by saline soils in the chernozem zone, where climatic conditions favor the cultivation of a wide variety of crops. The area of soil salinity is 631 thousand ha, including 450 thousand ha under arable land. The vastness of the areas of distribution and the need for the practical use of saline soils for the cultivation of crops determines the urgency of increasing their productivity through the use of mineral fertilizers. Sunflower is a culture of early spring sowing; the germination of seeds begins at temperatures 4–5 ℃. Although yields of sunflowers are not high, they are stable. To a large extent, this is explained by the moisture supply of this crop, which, taking into account the amount of precipitation and evaporation during the growing season, is 82–84%, which ensures a yield of sunflower seeds of 20.0 kg/ha or more.