The Functional Relationship between Energy Inputs and Fruit Yield: A Case Study of Stake Tomato in Turkey

Abstract

This research investigated the relationship between fruit yield and energy inputs used in stake tomato production under field conditions in Tokat province, Turkey. Energy use patterns in tomato production were also determined. Cross sectional data were obtained through face-to-face questionnaires given to the farmers who produce stake tomato. The survey studies indicate that the most important energy inputs among overall energy inputs used in stake tomato production are diesel-oil with 42.71%, total fertilizer consumption with 33.25%, human power with 13.26% and machinery with 6.71%. The average stake tomato production within the farms investigated was 98,000 kgha−1, and total energy consumption was 93644.61 MJha−1. Likewise, the energy output-input ratio and energy productivity were calculated as .93 and 1.16, respectively. The results suggest that small size farms were more efficient than large ones in terms of input use. According to the surveys, of the total energy used, 57.12% was in the form of direct energy and 77.54% was in the form of non-renewable energy. The effect of variables that explain stake tomato production was estimated by an econometric model developed using the Cobb-Douglas type function. In this model, stake tomato yield was considered as an endogenous variable, and fertilizer, chemical, machinery, human power, water for irrigation, diesel-oil, and seed energies were treated as exogenous variables. Elasticity coefficients of diesel-oil, human power, fertilizer, chemical, and water energies were found to be statistically significant. These results reveal that stake tomato production in Turkey heavily depends on fossil fuels. Therefore, adoption of new agricultural practices in stake tomato production, and further research on improvement and use of alternative energy sources are required.