Growing vegetables and fruits in greenhouses has become a mainstream choice for mid-to-high-end agriculture. Taking vegetables as an example, greenhouse cultivation indeed offers many advantages, but there are also some points to note regarding irrigation. Below, CHENGSA Holdings explains.
1. Pay attention to the timing of irrigation: In winter, greenhouse irrigation should generally be done on sunny days and avoided on overcast or snowy days; during the day, it is best done in the morning and generally not in the evening. Otherwise, it may lead to excessive humidity inside the greenhouse, which can easily trigger diseases. Irrigation should also be avoided at noon to prevent high-temperature watering from affecting the physiological functions of the roots.
2. Pay attention to controlling the water temperature for irrigation: In winter, greenhouse irrigation should use underground well water directly. The irrigation water temperature should preferably not be lower than 2–3°C, and avoid using cold water from rivers, reservoirs, or ponds directly. For winter vegetable planting, warm water at 20–30°C is recommended.
3. Pay attention to mastering the amount of irrigation water: Severe water deficiency in greenhouse vegetables can lead to plant wilting and leaf scorching, while excessive water can cause root suffocation and rot due to soil hypoxia, resulting in yellowing or even death of the above-ground stems and leaves. In winter, greenhouse irrigation water temperature is low, ventilation is minimal, and water consumption is reduced, so frequent small-scale irrigation is necessary. The amount of irrigation must align with crop water consumption, soil evaporation, and the tolerance level of the crop roots, ensuring neither over-irrigation nor water shortage.
4. Pay attention to selecting irrigation techniques: Micro-irrigation can effectively control air humidity in the greenhouse, reduce the occurrence of pests and diseases, and preserve effective light and heat resources. Micro-irrigation also effectively controls water volume, reduces deep soil seepage and fertilizer loss, improves soil structure and aeration, and promotes crop growth and development. Therefore, micro-irrigation is recommended for greenhouse vegetables.
5. Pay attention to strengthening post-irrigation management: On the day of irrigation, to restore ground temperature as quickly as possible, the greenhouse is generally closed to rapidly increase the indoor temperature. Once the ground temperature rises, for crops that prefer dry air, timely ventilation should be carried out to reduce humidity and lower the temperature to a suitable range. After irrigation during the seedling stage, multiple rounds of cultivation should be performed to increase temperature and preserve soil moisture. As the seedlings grow, cultivation may easily damage the roots and is generally no longer practiced.
