Hamdollah Eskandari; Ashraf Alizadeh-Amraie
Abstract
Energy efficiency is an important index for evaluating the sustainability of cropping systems. Therefore, the effect of supplemental irrigation on grain yield and energy efficiency of barley was evaluated under dry land farming system. The experiment had two treatments (with and without supplemental ...
Read More
Energy efficiency is an important index for evaluating the sustainability of cropping systems. Therefore, the effect of supplemental irrigation on grain yield and energy efficiency of barley was evaluated under dry land farming system. The experiment had two treatments (with and without supplemental irrigation at flowering stage) and seven replications. Grain yield was evaluated by measuring grain yield, spike per unit area, grain per spike, 1000-grain weight, biological yield and harvest index. Energy efficiency of the system was evaluated by calculating input energy and output energy of the system used for measuring energy ratio and net output energy indices. Results indicated that supplemental irrigation at flowering stage, increased barley grain yield from 1523.56 to 2259.29 kg.ha-1 affected by grain number per spike, since 1000-grain weight and spike per unit area were not significantly affected by supplemental irrigation. Total energy input of barley dry land farming was 29812 MJ.ha-1. Supplemental irrigation was resulted in 683 MJ.ha-1 energy addition to cropping system. However, because of 48 percent increasing in grain yield resulted in 10819 MJ.ha-1 energy output of the system, which increased energy ratio and net output energy to 45 percent and 10133 MJ.ha-1, respectively. Therefore, a supplemental irrigation at flowering stage, addition to increasing of grain yield, can improve energy efficiency of barley dry land farming system.
Hamdollah Eskandari
Abstract
Effect of complementary irrigation during reproductive growth stage on grain yield, percent and yield of oil and energy efficiency of rapeseed was evaluated in a dry land farming system. Experiment was conducted with three treatments (without complementary irrigation, one complementary irrigation during ...
Read More
Effect of complementary irrigation during reproductive growth stage on grain yield, percent and yield of oil and energy efficiency of rapeseed was evaluated in a dry land farming system. Experiment was conducted with three treatments (without complementary irrigation, one complementary irrigation during flowering and two complementary irrigations during flowering and grain filling periods) and three replications. Results indicated that silique number, grain number per silique, 1000-grain weight, biological yield, harvest index, percent and yield of oil were significantly (P≤0.01) improved by complementary irrigation. One and two complementary irrigation improved grain yield by 56 and 91 percent, respectively. Oil percent increased by one and two complementary irrigation from 32.18 to 35.0 and 37.22 percent, suggesting the improvement of oil yield up to 43 and 75 percent, respectively. Total energy input of barley dry land farming was 29007 MJ.ha-1, where the height input energy was belong to fertilizer. Supplemental irrigations increased input energy of the system. However, 488 and 789 kg/ha increasing in grain yield of one and two complementary irrigations resulted in 10596 (56 percent) and 17121 (91 percent) MJ.ha-1 of energy output of the system, respectively, suggesting supplemental irrigation can improve energy efficiency of rapeseed dry land farming system.
Arefe Razzazi; Majid Aghaalikhani; Barat Ghibadian; Behnam Zand; Sayyed Mohammad Safyeddin Ardabili
Abstract
Castor bean (Ricinus communis L.( with a capability to withstand harsh conditions, low nutritional needs, 50 percent of oil content and high- quality, is one of the best crop used to produce biodiesel. The first step toward introduction and widespread cultivation of this crop is to investigate the energy ...
Read More
Castor bean (Ricinus communis L.( with a capability to withstand harsh conditions, low nutritional needs, 50 percent of oil content and high- quality, is one of the best crop used to produce biodiesel. The first step toward introduction and widespread cultivation of this crop is to investigate the energy balance for its cultivation. To do so, energy input (include renewable and nonrenewable) and output were calculated through an examination of all inputs during two consecutive years of cultivation (2012-2014) in Varamin county in Tehran province. Energy indicators were also assessed. Result showed Indirect, non-renewable sources of energy with 59.68 and 80.86 percent of 11245.64 MJ energy consumption, comprise the major part of the consumable energy in castor bean cultivation. Moreover, among inputs fertilizers and pesticides with the share of 55.26 percent of the total consumable energy considered as the highest energy inputs. Fuels with the share of 21.28 percent formed placed at the second rank of consumable energy. Energy use efficiency in seed production was calculated to be 3.81, which is a considerable amount when compared with other crops used to produce biodiesel. Therefore, in order to expand the cost efficient and mechanized system of castor production, breeding of the current local ecotypes is recommended.