Optimization of water distribution bed and its effects on water productivity, crop yield and nutritional indicators of pistachio trees

water productivity in pistachio trees

Abstract

This research was carried out in Sarvestan city of Fars province in the southwest of Iran. Due to successive droughts, the groundwater resources of this city have decreased in terms of quantity and quality. Therefore, deficit irrigation in this area is inevitable and occurs mainly by increasing the irrigation cycle in pistachio orchards. Hence, a study was conducted in a pistachio orchard of Ahmad Aghaei cultivar in Sarvestan city during 2018-2020 with the aim of comparing irrigation water productivity, crop yield and machine farm efficiency in different water distribution substrates in the surface irrigation method with constant irrigation cycle. The experimental design was performed in the form of randomized complete blocks with 4 treatments of irrigation management in three replications. The treatments were: conventional flooding method with a strip width of 6 meters (Control treatment), the creek created on both sides of the tree row (Ditcher), reducing the strip width through the border created in the middle of the row of trees (Border) and the bed of Sine-Morghi created on both sides of the rows of trees (Kadval). The amount of irrigation water according to the inflow to each treatment and the time of cut off based on the management applied by the gardener in Control, Border, Kadval and Ditcher treatments was 8400, 4648, 4200 and 3080 cubic meters per hectare, respectively. The results showed that in both years of experiment in all treatments, irrigation water productivity increased compared to the control treatment. So that in the first year that the trees had good yield, the rate of increase in Ditcher, Kadval and Border treatments compared to the control treatment was 120, 91 and 62%, respectively. Also, according to the results of calculating the nutritional indices of pistachio leaf nutrients, it was observed that Ditcher treatment had the highest nutritional balance in the first year (1.6) and second (26.5) compared to the control. In terms of farm efficiency, there was no significant difference between the three types of Ditcher, Border, and Kadval machines, so there is no difference between their selection in the preparation of a water distribution bed for pistachio trees. Finally, Ditcher treatment was proposed as the best irrigation treatment for pistachio trees in the tested orchard.