عنوان مقاله [English]
Energy is of particular important in agricultural inputs due to the increasing rate of consumption, fossil fuels adverse impacts on the environment and limited sources. Due to the growing demand of energy, increasing world population, increasing food consumption per capita and improvement of life quality, the energy, the way it consumes and increasing its efficiency and optimization are very important. Moayedi et al (1388) indicated that the highest energy consumption of the first year of saffron cultivation was related to manure application with a 16.91% of the total energy consumption and in the second to fifth to urea fertilizer with a 67/37% of the total energy consumption. Similarly, energy production to consumption ratio over a period of five years of saffron cultivation was estimated to be 41/0. Ahamadi & Aghaalikhani, (2013) reviewed the energy consumption of cotton in the Golestan province. They considered the share of energy use in cotton in Golestan province, the share of energy consumption in tractor fuel inputs and fuel pump to be 24%, 30% respectively, and 54% of the energy was related to diesel fuel. Fertilizers had 24% and chemicals had 13% of energy consumption, and the total energy input for the production of cotton in Alborz Province was announced to be 31 GJ per hectare. Considering the energy crisis in the world, exploring the demand and consumption rate of energy and finding solutions to reduce the consumption is of researcher’s priority globally. Considering the privileged position of cotton production in the world and Golestan province of Iran, estimation of energy input and, efficiency are among the main research areas leading to fruitful solutions of optimizing energy consumption of the product.
Materials and Methods
A hundred of cotton fields around the Aliabad and AqQala cities in Golestan province were selected during two sowing years of 2014 and 2015. These farms were selected in such a way a number of farmers can be included. Important dates of different operations and events were observed during the growing seasons in selected fields. The data of typical production methods and cultivation practices were collected in last year including the use of equipment and fuel, application of fertilizers and pesticides and so on. Accordingly, all agricultural practices were divided into eight categories, including land preparation, planting, fertilizer application , plant protection, weed control, irrigation, harvesting and transportation to factory or crop delivery, primarily. Then, the different amounts of input use and more comprehensive information were collected and recorded at every single stage from planting to harvesting.
Results and Discussion
The results showed that the highest energy consumption was related to irrigation with 41% of the total energy and fertilizer application and land preparation were in the next positions. Labor force energy was calculated to be 2262 MJ.ha-1 related to harvesting, irrigation, cultivation, and crust-breaking. 61% of the total energy (10217 MJ.Ha-1) was used indirectly for the manufacturing, repair and maintenance of equipment and machinery, and production of seed, nitrogen fertilizer, phosphate fertilizer, potassium fertilizer, organic fertilizer, t insecticides, herbicides and industrial fungicides. Nitrogen fertilizer production consumed 30 percent of indirect energy sources, the highest share, while 39 percent of the total energy consumption was related to direct energy through the use of human resources and fuel consumption. Average power ratio of total farms was equal to 92.5. The results of levels of total energy input to fields showed that the minimum and maximum energy inputs were 15614 and 43321 MJ per hectare, respectively.
The results of this study showed that most of the direct energy (labor and fuel) consumption for cotton production is related to fuel with 86 % of the total energy mostly used in irrigation practices. Several factors such as soil texture, farm leveling, plant's feeding and protection, equipment and types of pumps, irrigation equipment maintenance in a timely manner, weather conditions, the amount of water available and most importantly short-term and long-term management are among areas which can reduce fuel and energy consumption of irrigation practices in the cotton production farms of Golestan province.