Evaluation of energy efficiency and ecological productivity of wheat and potato agroecosystem ecosystems in Borujerd city, Lorestan province

This study was carried out to assess and compare to energy, management of resources, especially water and increase the efficiency of irrigated wheat and potato.With the increase in population and the limitations of production resources in the future, it will be difficult to access energy sources in sufficient quantity. Efficient use of agricultural energy is one of the important factors in achieving sustainable agriculture. Sustainability is one of the main components of agricultural production that leads to food security and utilization of production resources for present and future generations. The efficiency and stability of crop systems vary according to the type of input energy management.The study was conducted to evaluate and compares the course of energy, the productivity of resources, especially water, and increases in the efficiency of irrigated wheat and potato agroecosystems.                                                  

At present, in most conventionally managed crop ecosystems, the share of indirect, non-renewable and commercial energy was higher than direct, renewable and non-commercial energy...This research was conducted in the crop years of 2017 in Borujerd city, Lorestan province, in the geographical location of 34° 1′ N latitude and 48° 4′ E longitude. The data used in this study are collected by questionnaire. The number of samples was determined by Cochran formula. Accordingly, 130 irrigated wheat farms and 60 potato farms were selecte by stratified random sampling method. In order to calculate the energy equivalent of inputs and outputs in the two canvases of irrigated wheat and potato crop system, first the most important inputs and outputs and their energy equivalent in the two canvases of the system were determined. Then, the equivalent of each input energy as well as output was calculated by multiplying its raw value by the corresponding energy conversion factor, the input energy input and the water flow rate in the two potato and irrigated wheat cropping systems.

The total amount of input energy were in potato (92645.73 MJ ha-1) and in irrigated wheat (45215.33 MJ ha-1). In terms of electricity, fossil fuel, chemical fertilizers and irrigation water, the potato agroecosystem had the highest amount of energy consumption. The consumption of non-renewable and indirect energy from the total input energy was high in both agroecosystems, especially potato cultivation showed more dependence on these input energies. This can indicated the instability of the potato agoecosystem compared to irrigated wheat. The amount of net energy index in the potato cropping system is higher than that of irrigated wheat, and indicates lower energy loss in potato cultivation. But because of the higher energy consumption efficiency in irrigated wheat compared to potato cultivation, this indicates the greater than of efficiency of the irrigated wheat farming system in converting input energy into available energy for yield.

Production systems should not be used for more than of their capacity in order to generate high revenue. As energy input increases, energy efficiency decreases Proper and efficient use of available resources increases the sustainability of production Therefore, conventional potato production is not sustainable in terms of energy consumption, because a very high percentage of consumption inputs in the potato production are non-renewable energies.. The consumption of non-renewable and indirect energy from the total input energy was high in both agroecosystems. The amount of net energy index in the potato cropping system is higher than that of irrigated wheat, and indicates lower energy loss in potato cultivation. This can indicated the instability of the potato Therefore it is suggested the cultivation of irrigated wheat, which was more stable, to the farmers of the region.Therefore, autumn irrigated wheat cultivation is more practical than spring and summer potato cultivation, which has a high water requirement and higher cost.