EFFECTS OF SOIL TILLAGE METHODS AND ORGANIC FERTILIZATION ON YIELD AND SOIL ORGANIC MATTER IN SLOPING OLIVE ORCHARDS OF KILIS

摘要

Drought is the most important factor that has been directly affected the plants growth and crop yield in semi-arid regions. The United Nations Food and Agriculture Organization (FAO) defined if somewhere annual rainfall is 300 mm or less called semi-arid regions and between 300-600 mm called arid regions. A large part of our country has arid and semi-arid agricultural regions. In Turkey, these regions are more affected by negative effects of global climate changes. Especially in Southeast Anatolia Region have a low and irregular rainfall, high evaporation and high temperature and this caused agricultural drought in arid farming areas. In these agricultural areas has a high economic value varieties such as pistachio, vineyard and olive produced with non-irrigation especially in Gaziantep, ?anliurfa and Kilis in Turkey. These fruit gardens are usually planted on inclined and non-fertilizer soils. Olive producer farmers used soil tillage the direction of land slope to save fuel and labor costs for their economic gains. Besides soil tillage direction and frequency also important these inclined olive orchards. Our farmers carry out soil tillage 4 times and same direction as slope under arid conditions. Thus, efficient surface soil has transported by erosion and then soil organic matter has decreased. Olive production yield is reduced in from year by year. In this study carried out between 2015-2016 years in two olive orchards that has been used different soil tillage. One of olive producer using conventional tillage (horizontal to slope) and another olive producer using vertical direction (vertical to slope) have determined. Olive trees are 20 years old and Gemlik type olive variety and in yield age. To increase the soil organic matter, 20kg tree farm manure has been applied to total of 40 olive trees in their each olive orchard. Conventional application has not been applied fertilizers. We were investigated that soil tillage shapes effects on soil organic matter content in this olive orchards. According to the results, highest soil moisture obtained from vertical tillage and organic fertilizer application with 24.18% in 20-40cm and lowest moisture obtained from traditional application with 11.70% in 0-20cm soil depth. Soil moisture values were low in top soil than subsoil in both research years. Soil organic matter ranged from 0.87% to 2.02% and best olive yield was determined average 34.5kg/tree from vertical soil tillage and manure fertilizer application in 2016 olive production year. Region farmers must know soil water conservation with vertical tillage to slope thus, protected soil moisture, soil organic matter and olive yield can increase in their olive orchards. Additionally organic manure using provided that soil and water conservation in semi-arid region. It was benefit to sustainability in non-irrigation agriculture areas.