Effect of planting date and plant density on potato yield, approach energy efficiency

ABSTRACT: Sustainable development in potato production is an issue of growing concern. Today, population growth, the need to further the cause of human food, agricultural and energy development in the agriculture sector is. Excessive consumption of energy (According to the exhaustible energy resources) the lack of stability in the future will produce. The effect of planting date and plant density on the yield and efficiency of energy production in potato tubers has been investigated. The experiment was conducted in split-plot design with four replications. Main plots consisted of 4 treatments, planting dates, 15 April (T1), 30 April (T2), 15 May (T3) and 30 May (T4), respectively. 3 in plots treated plant (plant spacing in the row) of 15 cm (D1), 25 cm (D2) and 35 cm (D3) were investigated. Results showed that the effect of planting date on yield was significant (p < 5%). So, planting dates thirtieth April, May fifteenth and thirtieth respectively, with an average yield of 33/22, 50/21, 30/18 tons per hectare in one group were statistically and sowing dates later than the first planting date (15 April) were superior. Results showed that among treatments, maximum and minimum of potato yield was related to T2 and T1, respectively. Plant density on yield was quite effective (p < 1%). Treatment plant row spacing of 25 cm with an average of 25.67 tons per hectare was higher than other treatments had the highest yield and Treatment plant and row spacing 35 cm with an average of 04/13 tons per hectare, the lowest yield among the treatments themselves. The interaction between planting date and density had no significant effect on yield. However, in planting dates, May 15 and 25 cm was obtained the maximum yield (29.92). The amount of energy consumed to produce one hectare of potatoes was 5922.41MJ. Machine operation consists the highest portion of direct energy inputs (12.88%) and average direct energy was about 5922/41 (13.88%). Average indirect energy inputs was about 36761 MJ/ha (86.13%). Water consists the highest portion of indirect energy inputs and average indirect energy was about 36761 MJ/ha (86.13%). Total energy input in one hectare of potato was 42683.4MJ. Average output energy per hectare calculated 70659 MJ/ha. Energy efficiency, energy productivity, energy intensity and energy gain estimated. In potato, energy efficiency was 1.3. Maximum and minimum of energy efficiency and energy productivity was related to T2 and T1. Fertilizers and seed consumption in potato reduction is high, so energy consumption will increase. Because most energy consumption related to water and fertilizer inputs. Therefore, new irrigation methods (such as irrigation type), and the precise application of fertilizer and other inputs,resulting in energy savings and optimal use of agricultural inputs. Also, much energy is directly related to agricultural machines, and the highest energy consumption in the operation of the machine is plowing. Having regard to the time of planting density and yield, the use of new methods of tillage (conservation tillage) and use combined machines (performing multiple job), In addition to reducing agricultural practices and environmental hazards, the savings in energy consumption will lead to sustainable agricultural production.