Detailed Explanation of Key Scientific Irrigation and Drainage Techniques for Dragon Fruit
Soil moisture status is closely related to tree development, high yield, stable yield, and tree lifespan. Maintaining soil moisture within a range favorable for fruit tree growth and development through irrigation and drainage is an important task in orchard soil management. 1. Irrigation Water is the lifeblood of plant growth and an indispensable component of all organ activities...
Soil moisture status is closely related to tree development, high yield, stable yield, and tree lifespan. Maintaining soil moisture within a range favorable for fruit tree growth and development through irrigation and drainage is an important task in orchard soil management.
1. Irrigation
Water is the lifeblood of plant growth and an indispensable component of all organ activities. In the life activities of fruit trees, water plays a role in maintaining cell turgor pressure, ensuring stomatal opening and carbon dioxide entry. All chemical changes within the body can only proceed under conditions where water is present. Nutrients in the soil can only be absorbed and utilized when dissolved in water. More importantly, water is an essential raw material for photosynthesis and the foundation for yield formation. In addition, only under conditions where water is present can fruit tree transpiration be maintained, tree temperature be regulated, and the transport of photosynthetic products and mineral nutrients be ensured. Therefore, in fruit tree cultivation, timely watering is an important measure to ensure early fruiting, high yield, and high quality.
(1) Irrigation timing. Irrigation should be carried out before fruit trees are affected by water deficiency, and absolutely must not be delayed until fruit trees already show signs of drought stress (such as wilting or fruit shriveling). Determining whether watering is needed mainly depends on soil moisture. Generally, 60%-80% of the soil's maximum water-holding capacity is most suitable for fruit tree growth and development. Dragon fruit has long grown in desert regions and has a relatively strong tolerance for water deficiency. In foreign countries, measuring instruments are generally used to determine soil moisture to guide irrigation. In addition to soil moisture, determining the irrigation timing should also consider climatic conditions and the growth and development stage of the fruit tree itself. In production, watering is mostly carried out during the following periods.
① From before bud break to the flowering stage. If there is sufficient water in the soil at this time, it can strengthen new shoot growth, increase leaf area, enhance photosynthesis, and ensure normal flowering and fruit set, laying the foundation for a bumper harvest that year. In spring drought areas, this irrigation is particularly important.
② New shoot growth and young fruit enlargement stage. This period is often called the critical water requirement period for fruit trees. At this time, the physiological functions of the fruit tree are most active. If water is insufficient, the leaves take water from the young fruit, causing the young fruit to shrivel and drop.
③ Rapid fruit enlargement stage. This watering can meet the fertilizer and water requirements for fruit enlargement. However, the amount of watering at this time must be well controlled.
④ Before and after harvest and the dormancy period. In arid autumn and winter regions, irrigation at this time can store sufficient water in the soil, help decompose fertilizers, and thereby promote the growth and development of fruit trees the following spring. After the last batch of dragon fruit is harvested in autumn and winter, the plant enters the dormancy period. If appropriate irrigation is provided at this time, it can promote plant growth and encourage branches to become fruiting branches as quickly as possible.
(2) Irrigation methods and irrigation amount
① Flood irrigation. In areas with abundant water sources and flat terrain, whole-orchard irrigation is often practiced. However, this method causes certain damage to soil structure, is labor-intensive and time-consuming, and is not economical, so it has gradually been adopted less.
② Border irrigation. Build a tree basin around each plant, or make long borders along the tree rows. During irrigation, lead water into the tree basins or borders. This method saves water and is easy to manage, so it is widely used. However, it likewise damages the soil structure of the tree borders and causes the death of absorbing roots.
③ Hole irrigation. When water sources are scarce, dig 8-12 holes with a diameter of about 30 cm outside the outer edge of the tree canopy drip line. The depth of the holes should be such that roots are not injured. Pour water into the holes and fill them level after the water infiltrates.
④ Furrow irrigation. Dig irrigation furrows at regular intervals between 2 rows of trees, with a depth of 20-30 cm and a width of about 50 cm. Generally, 2 furrows are made per row; in dwarf and densely planted orchards, 1 furrow may also be made. Lead water into the furrows to gradually infiltrate into the soil. This method saves water and causes less damage to soil structure, so it should be promoted.
⑤ Drip irrigation. Drip irrigation is an advanced irrigation technology developed in recent years through mechanization and automation. It is a watering method that slowly applies water droplets or fine streams to the plant root zone. It is now gradually being adopted in production. Drip irrigation has many advantages: for example, it only moistens the soil layer near the crop roots and the surface soil, greatly reducing water evaporation; this system can be fully automated, reducing labor to a minimum; moreover, it can regularly supply water to the root-zone soil, evenly maintain soil moisture, prevent excessive wetness and excessive dryness, and at the same time maintain good aeration in the root-zone soil. If drip irrigation is combined with fertilization, it can further continuously supply nutrients to the root system, which is most beneficial to fruit tree growth and development, achieving two goals at once. According to foreign reports, drip irrigation can increase fruit tree yield by 20%-50%. However, drip irrigation systems require more piping materials and a relatively large investment, and require a water tower with a certain pressure and a filtration system, as well as main pipes and branch pipes leading water into the orchard, and capillary tubes and emitters surrounding the trees. In addition, pipes and emitters are easily clogged, strictly requiring good filtration equipment.
Regardless of which irrigation method is used, the amount of water applied at one time must not be too much or too little; it is suitable to thoroughly wet the soil layer where the main root system is distributed. Specifically determining the irrigation amount also requires considering soil texture, fruit tree growth and development stage, fertilization conditions, and meteorological conditions. For theoretical calculation of irrigation amount, determining it based on soil moisture is the most commonly used. It is generally believed that the minimum irrigation amount is when soil moisture is 60% of the soil's maximum water-holding capacity, while the ideal amount is 80% of the maximum water-holding capacity. In addition, based on the long-term accumulated experience of fruit growers and technicians, when watering is considered to have thoroughly penetrated, that is actually the most suitable irrigation amount.
2. Drainage
The roots of dragon fruit are most afraid of oxygen deficiency and avoid waterlogging. When there is too much soil moisture, aeration weakens, which hinders root respiration. In severe cases, it can suffocate the active parts to death, causing fruit drop, reducing fruit flavor, and even causing plant death. Therefore, in addition to good water conservation and timely irrigation, flood prevention and waterlogging drainage work should also be done well, such as building drainage ditches and flood discharge channels, and preparing for flood prevention and drainage in rainy seasons. The number and size of drainage ditches in the orchard should be determined according to the local rainfall amount, the strength of the soil's water-holding capacity, and the height of the groundwater level. Under normal circumstances, the drainage ditches in a dragon fruit orchard are about 1 m deep.
Click to view more dragon fruit cultivation techniques
Click to view more fruit cultivation techniques