Determination of the effect of drip irrigation on soil salinity in walnut orchards

In this study, the changes in soil salinity in walnut orchards of different irrigation water applications under the drip irrigation method were investigated. The research was carried out in Tekirdag conditions in 2019. In the study, three different irrigation water applications were applied to walnut trees, in which 75, 100 and 125 % of the evaporation values measured from the A class evaporation pot were applied during the 5 day irrigation interval. Irrigation water between 361,48 and 602,44 mm was applied to the treatments with 18 times irrigation application. As a result of the research, the evapotranspiration values measured during the plant growing season in the treatments varied between 575,98 and 809,94 mm depending on the amount of irrigation water applied. The daily evapotranspiration values varied between 1,44 and 8,67 mm day-1. In the study, measurements for the change of soil salinity with irrigation practices were carried out at 7 different sampling points, in 3 different times, before the irrigation season, in the middle of the irrigation season and at the end of the irrigation season. It was determined that the soil salinity increased in all profiles at the end of the irrigation season in the experiment in which 75% of the evaporation values measured from the Class A pan were applied. In addition, it was observed that the amount of salinity increased in the profile between the two drippers (3) and in the profile (2) located in the middle of the two laterals in all trial subjects with irrigation applications. Also, the changes in soil pH values of different irrigation water applications were investigated. The obtained pH values decreased in the middle and end of the irrigation season at all measurement points. As a result, it has been revealed that monitoring and control stages are important for the control of salinity, especially with irrigation practices, in terms of the protection of soil and water resources in the Thrace Region.