Econometric model estimation and sensitivity analysis of inputs for mandarin production in Mazandaran province of Iran

This study examines energy consumption of inputs and output used in mandarin production, and to find relationship between energy inputs and yield in Mazandaran, Iran. Also the Marginal Physical Product (MPP) method was used to analyze the sensitivity of energy inputs on mandarin yield and returns to scale of econometric model was calculated. For this purpose, the data were collected from 110 mandarin orchards which were selected based on random sampling method. The results indicated that total energy inputs were 77501.17 MJ/ha. The energy use efficiency, energy productivity and net energy of mandarin production were found as 0.77, 0.41 kg/MJ and -17651.17 MJ/ha. About 41% of the total energy inputs used in mandarin production was indirect while about 59% was direct. Econometric estimation results revealed that the impact of human labor energy (0.37) was found the highest among the other inputs in mandarin production. The results also showed that direct, indirect and renewable and non-renewable, energy forms had a positive and statistically significant impact on output level. The results of sensitivity analysis of the energy inputs showed that with an additional use of 1 MJ of each of the human labor, farmyard manure and chemical fertilizers energy would lead to an increase in yield by 2.05, 1.80 and 1.26 kg, respectively. The results also showed that the MPP value of direct and renewable energy were higher. © Maxwell Scientific Organization, 2011.