A decade-long study on the effect of furrow and subsurface drip irrigation using unconventional water on soil salinity and the growth of pistachio trees

Furrow irrigation is the most common method of irrigating pistachio orchards in Iran. Water use efficiency using this close to 35%. Ten years ago, a subsurface drip (SDI) project was initiated with highly saline and alkaline water for first time Iran at Feyzabad research station, 34̊ 54ʹ 15ʺ N, 58̊ 45ʹ 37ʺ E, located northeast Iran, an altitude 850 meters from sea. The salinity sodium adsorption ratio were 11.5 dS m-1 15.5 beginning project, they reached 16.25 17.7 2021. amount SDI consumption year (2012) 1640 m3 ha-1 yr-1, as trees aged, 3000 2022. utilized furrow about 6912 Salt entering soil through differed by 41 t 2022 between two methods. After ten implementation, root development layer more than 100 cm less 50 cm, respectively, furrow. trend has changed 2012 2022: it went 34.7 110 2018, then decreased 65 surface method. In contrast, increased almost twofold within (60-140 cm) SDI. last (2021 2022), height, crown width, trunk circumference, yield not significantly different However, there significant difference treatments during 2022) annual growth, average number flower buds branch, abscised. branch vegetative growth had 50% compared 2021 both results showed that lowest achieved Overall, equal 0.09 0.06 kg m3, respectively. net income 1284 $ higher after expenses deducted Therefore, due severe climate change excessive increase resources, well-managed can provide sustainable production salt-affected soils reducing salt entry into soil.