The Amount of Fresh Water Production in Solar Distillers Connected to the Greenhouse to Provide Water Requirement of Basil Crop in Ahvaz

Desalination of salty and unconventional water is an opportunity for sustainable development especially in arid and semi-arid regions. In this research, a greenhouse was constructed at Shahid Chamran University of Ahvaz and six solar distiller devices mounted on it. Its four devices were mounted on the roof and two other devices on the south wall of the greenhouse and used for desalination of saline water. Total amount of fresh water of six distillers was calculated on a daily basis. To estimate greenhouse evapotranspiration, a small evaporation pan and a soil water balance method were used. The effect of some meteorological parameters on the daily production of fresh water was investigated. The purpose of this research was to determine the fraction of fresh water produced by distillers to the basil crop water requirement in the greenhouse. Daily and periodic measurements of fresh water production were compared with daily and seasonal evapotranspiration of basil crop. The results showed that the average of basil evapotranspiration in the four stages of plant growth is respectively 1.97, 7.03, 8.22 and 8.11 mm/day. By increasing solar radiation and temperature and reducing cloudiness and precipitation, the fresh water production was increased. Wind speed and horizontal visibility have less effect on the fresh water production. The produced fresh water of six distillers during the four stages growing period of basil crop was measured to be 3.52, 4.62, 5.47 and 5.42 liters per day, respectively. Therefore, the produced fresh water at the beginning stage was 1.79 times of the basil ET and from the second to fourth stages it was about 0.67 of basil evapotranspiration. Evapotranspiration of basil plant during the 100 days of growing season, from April 21, 2018 to July 29, 2018, was measured to be 678.9 millimeter, of which %72 (488 liters per square meter sandy bed) was supplied by distillers.