During the spring and summer months, it is a good idea to run microsprinklers two or more times a week, except immediately after rainy periods. A good way to check soil water status and your irrigation schedule is to use tensiometers. Water movement into the soil will depend on the application rate. For young trees, increased growth is the main advantage of irrigating frequently for short durations. The upper soil layer where most of the roots are located is thereby kept moist and tree stress is minimized.
Growth is one of the first things affected by water stress.
Mild water stress slows growth and more prolonged stress stops growth entirely. The idea of irrigating approximately twice a week from March through June for short durations is to keep the upper soil horizon near field capacity, maximize growth, and minimize deep soil water loss. Table 3 shows a schedule designed to promote optimum growth so trees reach production size sooner and become profitable at an earlier age. If coverage is inadequate on mature trees, the microirrigation system may not be able to meet the water requirements of the large trees. Running the system for a longer time will probably not make up for the lack of coverage, and the longer running time will drive more of the water below the main root zone.