Walnut trees are known for having a large leaf surface because they are large and widely branched. For this reason, it is very important for the walnut tree to provide sufficient water to the walnuts with high water loss due to perspiration. For walnuts, it is very important to meet the water requirement during the spring development, fruit growth and filling periods. The lack of water during these periods will slow growth and development and cause the fruits not to fill them enough, so there is a high probability of low quality and yield. One of the most important issues to be considered in irrigation is that the water reaches the effective root level. In the first years, it is necessary to irrigate the walnut twice a week, taking into account the condition of the region and the water source. As the irrigation method, one of the furrow irrigation, flooding, drip irrigation and bottom sprinkler irrigation systems can be preferred.