One of the most important features we must seek on the land, where we shall grow walnuts, must be being free of irrigation problem. We must make our planning in advance for the irrigation of the saplings and conditions of irrigable land must be maintained after the plantation of saplings. We must know that we shall need water in our land, where we shall plant walnut saplings, for the growth of saplings and for the fruit quality in future, starting from spring and particularly in summer season.
Annual water need of a fully productive walnut tree is about average 1100 – 1300 mm levels.
Water requirement of walnut trees starts at the end of spring, and continued until the end of the harvesting period. Within this period, additional irrigation is needed due to the deficiency of rains within many regions of our country.
If we review the irrigation activities separately in terms of the saplings and fully productive trees:
Irrigation of Walnut Sapling;
a. The facts that the sapling pits opened during plantation have a suitable depth (a depth of 50-60 cm and a width of -40-50 cm in a normal soil structure) and obtaining the soil to be filled in the sapling pit by mixing the surface soil with either well burnt animal manure or leonardite are important in terms of a successful irrigation in the first years.
b. Irrigation of walnut starts with the sap to be given during the plantation of sapling so as to reach to the roots and saturate them (30-50 Lt).
c. If the saplings are planted in winter season, then sap must also be given, but additional irrigation must not be made, unless needed. The humidity of the soil caused by the rains is sufficient.
d. When the spring comes and the rains decrease, the water requirement of the walnut sapling shall increase and additional irrigation shall be needed. The fact that how and when our sapling shall need water is a matter related with the ability of the soil to keep water. Increase of the temperatures shall also increase the water need of the sapling.
e. Plantation must be carried out without taking measures in terms of irrigation, in case of plantations of tubed walnut saplings in summer seasons.
Matters to be observed when determining the water requirement of the sapling;
* You must determine the duration (minutes) and amount (litre) of the irrigation you shall make, by determining the depth (cm) that the water, which we recommend as 15-20 litres in each irrigation during the sapling period, reaches.
* You must observe that how many days the irrigation you make keeps the soil of the sapling humid, and adjust the irrigation frequency accordingly.
* In general, we recommend 15-20 lt of sapling irrigation in every 10 days, 7 days depending on the temperature and rain, and in every 3-5 days on very hot days.
* Water stress to be experienced due to failing to make irrigation may slow down the growth of root, body, and branches during sapling period, and may cause the sapling to dry out.
* Although less irrigation shall have damage on the sapling, irrigations to be made frequently (1-2) shall have negative effects of the growth of the sapling.
* As it is specified above, the fact that the humidity remains in your soil is your main indicators in terms of the amount and frequency of irrigation. You must make your irrigation planning according to the observations you shall make.
* In general, the intervals of sapling irrigation must be continued by reducing until 15 September. If drying is present in root regions of the sapling soil, thus in a depth of 15-20 cm, in our hot regions, then an additional irrigation may be made.