Investigating the Factors Affecting the Physical and Economic Productivity of Water in Production of Orange in Ghaemshahr County, Iran

One of the important problems in the agricultural sector of Iran is the low productivity of inputs, especially water. In this study, in addition to determining the physical and economic productivity of water, the factors affecting these productivities in the production of orange in Ghaemshahr County of Mazandaran Province were also investigated. For these purposes, three indexes of water use productivity including crop per drop (CPD), Gross benefit per drop (BPD), and net benefit per drop (NBPD) were used. Also, regression analysis was used to investigate the factors affecting water productivity. Necessary information was collected by completing 162 questionnaires from gardeners in the study area in 2018-19. Data analysis was also performed using Eviews7 software. The results of the analysis of water productivity indices showed that the average CPD index for orange was 6.9 kg /m3, BPD index was 47500 Rials and NBPD at three interest rates of 10%, 12%, and 15% was 29000, 28000, and 26600 Rials, respectively. Well’s discharge rate, days when wells were used, time spent for irrigation, the number of irrigations, age of trees, the distance between the trees, age of trees, cost of pesticide, and cost of fertilizer were the factors affecting water productivity. Among the mentioned variables, the variable of “time spent for irrigation” had the greatest effect on the physical water productivity, through the effect on the amount of irrigation water. Due to the negative effect of well discharge rate, the number of irrigations, and time spent on irrigation on the economic productivity of water, it is recommended to irrigate the orange trees in accordance with their needs and in a way that less water is applied.