تعيين نياز آبي و ضريب گياهي ريحان در شرايط كشت كنترل شده گلخانه

Determination of Water Requirement and Crop Coefficient for Basil (Ocimum basilicum L.) under Controlled Greenhouse

ﺗﻮﺳﻌﻪ ﮐﺸﺖ ﻣﺤﺼﻮﻻت ﮐﺸﺎورزي در ﻣﺤﯿﻂ ﮔﻠﺨﺎﻧﻪ، ﯾﮑﯽ از راﻫﮑﺎرﻫﺎي اﺳﺎﺳﯽ در ﻣﺪﯾﺮﯾﺖ ﺑﺤﺮان ﮐﻢآﺑﯽ اﺳﺖ. در اﯾﻦ راﺳﺘﺎ، آﮔﺎﻫﯽ از ﻧﯿﺎز آﺑﯽ ﮔﯿﺎﻫﺎن در ﺷﺮاﯾﻂ ﮐﺸﺖ ﮔﻠﺨﺎﻧﻪ و ﺗﺨﻤﯿﻦ دﻗﯿﻖ ﺿﺮﯾﺐ ﮔﯿﺎﻫﯽ از ﻋﻮاﻣﻞ ﻣﻬﻢ و اﺛﺮﮔﺬار در ﺑﺮﻧﺎﻣﻪرﯾﺰي ﺻﺤﯿﺢ آﺑﯿﺎري و اﻓﺰاﯾﺶ ﺑﻬﺮهوري آب اﺳﺖ. ﻫﺪف از اﻧﺠﺎم اﯾﻦ ﺗﺤﻘﯿﻖ ﻣﺤﺎﺳﺒﻪ ﻧﯿﺎز آﺑﯽ و ﺿﺮﯾﺐ ﮔﯿﺎﻫﯽ رﯾﺤﺎن در ﺷﺮاﯾﻂ ﮐﺸﺖ ﮐﻨﺘﺮلﺷﺪه ﮔﻠﺨﺎﻧﻪ اﺳﺖ. ﺑﺪﯾﻦ ﻣﻨﻈﻮر ﻣﻄﺎﻟﻌﻪاي در داﺧﻞ ﮔﻠﺨﺎﻧﻪ ﺗﺤﻘﯿﻘﺎﺗﯽ ﭘﺮدﯾﺲ ﮐﺸﺎورزي و ﻣﻨﺎﺑﻊ ﻃﺒﯿﻌﯽ داﻧﺸﮕﺎه ﺗﻬﺮان ﻃﯽ ﯾﮏ دوره رﺷﺪ، ﺑﺎ اﺳﺘﻔﺎده از ﻣﯿﮑﺮوﻻﯾﺴﯿﻤﺘﺮ اﻧﺠﺎم ﮔﺮﻓﺖ. ﻣﯿﮑﺮوﻻﯾﺴﯿﻤﺘﺮﻫﺎ اﺑﺰار ﻣﻨﺎﺳﺒﯽ ﺑﺮاي ﺗﻌﯿﯿﻦ دﻗﯿﻖ ﺗﺒﺨﯿﺮ- ﺗﻌﺮق ﮔﯿﺎه در ﺷﺮاﯾﻂ اﺳﺘﺎﻧﺪارد )ETc( ﯾﺎ ﺑﻪ ﻋﺒﺎرﺗﯽ ﺗﺒﺨﯿﺮ- ﺗﻌﺮق واﻗﻌﯽ ﮔﯿﺎه )ETa( ﻣﯽﺑﺎﺷﻨﺪ. در اﯾﻦ ﺗﺤﻘﯿﻖ، ﺗﺒﺨﯿﺮ- ﺗﻌﺮق ﮔﯿﺎه ﻣﺮﺟﻊ و ﻧﯿﺎز آﺑﯽ ﮔﯿﺎه رﯾﺤﺎن ﺑﺎ اﺳﺘﻔﺎده از راﺑﻄﻪ ﺑﯿﻼن آب در ﺧﺎك ﺗﺨﻤﯿﻦ زده ﺷﺪ. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﻧﺘﺎﯾﺞ، ﻣﺘﻮﺳﻂ ﺗﺒﺨﯿﺮﺗﻌﺮق ﮔﯿﺎه ﻣﺮﺟﻊ و رﯾﺤﺎن ﻃﯽ دوره رﺷﺪ ﺑﻪ ﺗﺮﺗﯿﺐ ﺑﺮاﺑﺮ ﺑﺎ 8/23 و 5/13 ﻣﯿﻠﯽﻣﺘﺮ ﺑﺮ روز ﺑﻪ دﺳﺖ آﻣﺪ. ﺳﭙﺲ ﺿﺮﯾﺐ ﮔﯿﺎﻫﯽ از ﻧﺴﺒﺖ ﺗﺒﺨﯿﺮ- ﺗﻌﺮق ﮔﯿﺎه ﺑﻪ ﺗﺒﺨﯿﺮ- ﺗﻌﺮق ﻣﺮﺟﻊ در ﻃﻮل دوره رﺷﺪ ﻣﺤﺎﺳﺒﻪ ﮔﺮدﯾﺪ. ﻣﺘﻮﺳﻂ ﻣﻘﺎدﯾﺮ ﺿﺮﯾﺐ ﮔﯿﺎﻫﯽ رﯾﺤﺎن ﺑﺮاي ﻣﺮاﺣﻞ اوﻟﯿﻪ، ﻣﯿﺎﻧﯽ و ﭘﺎﯾﺎﻧﯽ ﺑﻪ ﺗﺮﺗﯿﺐ ﺑﺮاﺑﺮ ﺑﺎ 0/86 ،0/30 و 0/76 ﺑﻪ دﺳﺖ آﻣﺪ.

The development of agricultural crop cultivation in greenhouse is one of the main strategies for managing water scarcity. Awareness of the crop water requirement and accurate estimation of crop coefficient is one of the most important component in irrigation scheduling and improving water use efficiency. The objective of this research was to determine water requirement and crop coefficient of basil in controlled greenhouse condition. For this purpose, a study was carried out in a research greenhouse of the College of Agriculture and Natural Resources, University of Tehran during a growth period using micro-lysimeter. Micro-lysimeters are useful tools for accurate determination of the crop evapotranspiration under standard conditions (ETc), or the actual crop evapotranspiration (ETa). In this study, the evapotranspiration of the reference crop and the Basil water requirement were estimated using the soil water balance equation. According to the results, average reference and basil crop evapotranspiration during the growth stage were equal to 8.23 and 5.13 mm per day, respectively. Then the crop coefficient was calculated based on the ratio of basil crop and reference evapotranspiration. The average basil crop coefficients for the initial, mid and end growth stages were obtained to be 0.30, 0.86 and 0.76, respectively.