This works best with a gutter-connected greenhouse where the water from the downspouts is piped to an above ground or below ground storage tank. Water from the tank is then used to irrigate plants during the daylight hours.Ĭollection of rainwater to supplement a well or surface system is also possible. Low flow wells can be set up to be pumped to a storage tank over a many hours. ![]() Zones can be sized to utilize the flow from a well or municipal source so that irrigation takes place all day long. Zoning, applying the water to one area or section of plants at a time, will allow a low flow water source to irrigate a larger number of plants. Most common is adapting low usage irrigation systems. Water supplies can be extended by several methods. ![]() The type of growing mix used also affects the amount of water holding capacity and therefore the frequency of watering. Often leaching accounts for a much higher percentage and can increase water needs significantly. Traditionally, the recommendation that at least 10% of the water applied be allowed to leach out to remove excess fertilizer salts increases water usage. Subirrigation systems such as ebb and flood systems, flooded floors and hydroponics conserve water by recycling and reusing the excess water. In-pot drips systems are much more efficient as all the water applied with an in-pot drip system gets to the soil. Only 20% of the irrigation water applied with an overhead sprinkler system may reach the soil in a potted plant crop with a large foliar canopy. A large root mass or heavy leaf canopy will increase water needs. Seedlings or small potted plants require less water than a full-grown tomato or cucumber crop. A 5 miles/hour breeze can increase evapotranspiration by 20%. Depending on location and nearby greenhouses or other buildings, sidewall vents and open-roof designs can also have an influence. Fan ventilation and HAF systems increase the rate of evapotranspiration. Depending on the level of shade, this will reduce evapotranspiration and therefore water needs. The use of shading outside or inside will reduce the radiation level on the plants. The level of radiation that reaches the plants is reduced by 10% to 40% due to the glazing and the structural members in the greenhouse. The following factors can increase or decrease the amount of water needed: For example a 30’ x 100’ greenhouse with 2400 square feet of benches would require a peak use rate of 720 to 960 gallons/day. A rule of thumb is to have available 0.3 to 0.4 gallons/square foot of growing area per day as a peak use rate for the warmest day. The design for the water supply needs to be made for the peak use time of the year. The amount of water needed depends on the area to be watered, crops grown, weather conditions time of year and the environment control system. Plants require an adequate supply of moisture for optimum growth which is affected by many variables. ![]() An adequate water supply is needed for irrigation, pesticide application, evaporative cooling (if applicable), growing media preparation and clean-up. Water is a major factor in successful production of greenhouse plants. Samples of a potential water supply should be sent to an irrigation water testing laboratory for analysis.Adapt low usage irrigation systems to extend a limited water supply such as zoning and low flow wells.Determine the amount of water needed based on crops grown, weather conditions, time of year and the environment control system.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |