Evaluation of yield reductions in vineyards in connection with the soil nutrient content: the Rumi grape variety

This study was conducted to determine the soil quality in vineyards where the Rumi grape variety is grown in Kilis Province. Low yields harvested in Kilis in recent years from the Rumi grape variety, which has high economic value, encouraged this study aiming to identify the cause. There is no fertilization in the vineyards submitted to the study, so the search for the reason for low yields was referred to the soil nutrient content. For this purpose, soil samples were taken from the soil in the vineyards at a depth of 0-30 cm. It was determined that the soil reaction varied from 7.19 to 8.34, 16.2% of the examined soils were neutral, and 83.8% were slightly alkaline. As regards the soil texture, 27% of the soils were loamy, 51% were clay loam, and 22% were textured clay. Although the lime content varied from 0.85% to 46.21%, 24.32% of the soil samples were found to be low calcareous, 16.21% were calcareous, 16.21% were found moderately calcareous, 24.32% were high in calcium and 18.91% were very highly calcareous. The organic matter content of the examined soils was determined at the lowest 0.62% and the highest 3.40%, with 5.40% of soils having very low, 35.13% – low, 51.35% – moderate and 8.10% – high organic matter content. The phosphorus content ranged from 1.04 kg da^-1 to 6.86 kg da^-1, and 29.72% of the soil were found contain very small, 67.56% – small, and 2.70% – moderate amounts of phosphorus. The potassium content ranged from 31.85 to 164 kg da^-1, and it was found that 5.40% of the soils had sufficient K content and 94.59% had high K content. Significant relationships have been found between the physical and chemical properties of the soil. As a result of the study, it is recommended to apply farm manure or green fertilization in vineyards where vineyard soils are ideal in terms of texture but organic matter deficiency is determined, and phosphorous fertilization is recommended in the presence of high pH and high lime content. The current fertility of the soil should be maintained and improved over the years.