Mentha piperita: Energy and Economic aspects of growth

The aim of this study is to analyze the energy and economic sustainability of the production process of Mentha × piperita L. var. Officinalis Sole f. Rubescens Camus, Mentha Italo-Mitcham [1]. Economic data from 2015 were collected directly from farms in one of Italy’s areas of traditional cultivation (Pancalieri and its surroundings), while the energy data came mainly from ‘standardized’ sources [1,2]. The work is divided into two parts: i) evaluation of the energy consumption; ii) evaluation of the economic sustainability. The total energy required was determined from the direct energy consumed (field activities) and the indirect energy consumed for tractor and implement manufacture. Machinery computations: was employed an energy content value of 92.0 MJ kg-1 (tractors) and an average 69.0 MJ for each kilogram of machine mass (all other equipment used for planting). Direct energy input was determined using an energy content of 37.0 MJ L-1 (diesel) and 83.7 MJ kg-1 (lubricant); each of these values increased by 1.2 MJ kg-1 to account for the fossil fuel used (their transport and distribution) [2]. Energy expended for maintenance and repair was assumed to be 55.0% of the energy required for machine manufacture [3]. Energy output was determined from the surface worked and mint harvested. Power used was calculated from measurements taken of the drawbar pull and power utilized in the different operating phases. Human work, expressed in manpower hours, was not included in the overall energy calculation. To evaluate the economic sustainability the Net Present Value (NPV) and the internal rate of return were determined, while to evaluate the profitability was determined the break-even point as difference between total income and total cost [4].