Micro-sprinkler : This is an irrigation method used in intensively managed orchards. Specially designed, aging-resistant plastic pipes are buried beneath the orchard surface, with one “high moon” device installed around the trunk circle of each tree. For a 30-centimeter sprinkler, simply open the water inlet valve when irrigation is needed to initiate spraying. The quality of the sprinkler directly affects its service life, while the fineness of the misted water determines the effectiveness of the spray. Micro-sprinklers allow precise control over the amount of water applied, deliver uniform coverage, and conserve water by maintaining soil looseness, promoting a crumbly soil structure, and preserving soil fertility. They also help regulate the microclimate, reducing damage to sweet cherries caused by low temperatures and dry heat. Moreover, before the onset of late spring frosts, employing an intermittent spraying method—spraying for two minutes followed by a two-minute pause—can delay cherry blossom emergence, thereby protecting the crop from frost damage.
( 3) Ribbon sprinkler irrigation: The method and characteristics are somewhat similar to micro-sprinkler irrigation. While micro-sprinklers have their piping buried underground, ribbon sprinkler irrigation places the water ribbon on the ground, allowing it to be easily rolled up and deployed as needed. The water ribbon is equipped with emitters at varying heights; by connecting the ribbon’s end to a water supply outlet, sprinkler irrigation can be carried out. Compared with conventional sprinkler systems, ribbon sprinkler irrigation requires lower initial investment, can be readily retracted when not in use, and is less susceptible to theft.

2. Irrigation Period
For micro-sprinkler and band sprinkler irrigation, watering can be applied at any time based on soil moisture conditions and climate. For flood irrigation, applications can be categorized as pre-flowering water, post-flowering water, pre-harvest water, and autumn fertilization water, among others.
Irrigation before flowering should be avoided whenever possible if the soil is not severely dry, as low air temperatures can cause a rapid drop in soil temperature after irrigation, leading to uneven bloom and impaired fruit set. If irrigation is necessary, apply only small amounts, using surface water or well water that has been exposed to sunlight to raise its temperature prior to application. From after bloom until just before harvest, fruit set, fruit enlargement, and new shoot growth all occur simultaneously, making this a period of high water sensitivity for sweet cherries—referred to as the critical water-demand phase. Typically, irrigation is applied after bloom, withheld during the stone-hardening stage, and resumed during the rapid fruit-enlargement phase up to harvest, with irrigation frequency adjusted according to rainfall conditions. In normal years, irrigate 1–2 times; in September, after applying the autumn basal fertilizer, provide a thorough soaking irrigation. In years with severe autumn drought, an additional irrigation is also recommended. Prior to soil freezing, however, no freeze-up irrigation should be applied, as sweet cherry trees have shallow root systems and enter dormancy early; otherwise, due to the low rate of winter soil moisture evaporation, post-irrigation conditions may impair root respiration. Fruit-bearing trees have specific water requirements during flowering and fruit set, drought-induced yellowing and fruit drop, stone hardening, and fruit expansion, as previously discussed. In the short period following harvest, when flower bud differentiation is underway, water application should be carefully controlled.
For newly planted seedlings, timely water supplementation is crucial. If the soil around the root zone—just below the surface—does not form a clod when squeezed in the hand, the seedlings are prone to “drying out and dying,” which is one of the main reasons for the low survival rate of sweet cherry transplants. Experienced fruit growers recommend applying what they call “cucumber water” after planting: water as soon as the soil surface dries, then hoe the soil after watering; repeat this cycle every 3 to 5 days. In the first year, irrigate 11 to 12 times to ensure seedling survival and promote rapid shoot growth. In the second year, irrigate 5 to 6 times.
In the later stages, water should be carefully controlled for vigorously growing young trees to prevent excessive vegetative growth, which can impair flower bud formation and compromise winter hardiness. “Draw a line.”
Under conditions where the soil is not severely dry, irrigation should be avoided during the following periods:
( 1) From the time the soil thaws until before flowering—this is known as pre-flowering irrigation.
( 2) The flower-bud differentiation period in June and July. Some fruit growers habitually apply fertilizer and irrigate after harvest to “replenish the tree’s strength,” but we believe this practice is unscientific. During the flower-bud differentiation period, watering should be restricted, and any topdressing should be applied as a dry application.
( 3) Frostwater that forms in the soil before it freezes. Sweet cherry trees are sensitive to waterlogging; after such flooding, symptoms include yellowing leaves, wilting, dieback of branches, poor tree growth, reduced yields, and even tree death, resulting in an uneven orchard stand and lower per-unit productivity. Waterlogging can also exacerbate the incidence of gummosis. Therefore, cherry orchards must have effective drainage to ensure that rainwater is drained promptly—ideally within two hours—so that no standing water remains in the orchard. In the event of heavy rainfall when natural drainage is inadequate, artificial drainage measures should be implemented; if necessary, mechanical pumping should be employed to prevent water accumulation in the orchard.