Energy Use Efficiency and Economical Analysis in Cotton Production System in an Arid Region: A Case Study for Isfahan Province, Iran

The objective of this survey was to evaluate the energy consumption and the economic analysis of cotton production in Esfahan province of Iran. For this purpose, data were selected from 47 cotton growers using a face-to-face questionnaire. The results indicate that cotton production consumed a total energy of 52507.8 MJ ha-1. Among sources of input energy, the contribution of energy related to diesel fuel (47%) was highest, followed by chemical fertilizers (20%) and water for irrigation (12%). The shares of direct and non renewable energy were 68.3% and 77.7%, respectively. The impacts of indirect and non-renewable energy on cotton yield were higher than those of direct and renewable energy. Energy use efficiency, specific energy, energy productivity, energy intensiveness, and net energy were 0.7, 19.2 MJ-1 kg, 0.10 kg MJ-1, 27.2 MJ-1 $-1, -15625.2 MJ-1ha-1, respectively. Total cost of cotton production was 1927.9$ ha-1. About 67% of the cost of production was variable costs, while 33% was fixed costs. The benefit to cost ratio was estimated 1.22. It is suggested that efforts to increase energy efficiency of cotton production in the investigated area should primarily focus on proper use of fertilizers and irrigation systems and also on saving diesel fuel by improving machinery operating performance. Keywords: economical assessment; energy consumption; energy intensiveness; energy productivity JEL Classifications: O13; Q12; Q4

Pulses Production Systems in Term of Energy Use Efficiency and Economical Analysis in Iran

Energy analysis of agroecosystems seems to be a promising approach to assess environmental problems and their relations to sustainability. The aim of the present study was to compare bean, lentil, irrigated and dryland chickpea farms in terms of energy efficiency, energy productivity, benefit to cost ratio and the amount of renewable energy use. Data were collected from 18 bean, 27 lentil, 24 irrigated chickpea and 46 dryland chickpea growers, using a face-to-face questionnaire during 2010. The results revealed that the total energy requirement were for bean 23666.8 MJ ha-1, for lentil 14114.79 MJ ha-1, for irrigated chickpea 15756.21 MJ ha-1, and for dryland chickpea 2630.12 MJ ha-1. The average energy input consumed in studied crops including direct, indirect, renewable and non-renewable energies in bean, lentil, irrigated chickpea and dryland chickpea farms were 67%, 33%, 30% and 70%, respectively. Energy use efficiency was 1.81 for bean, 1.79 for lentil, 1.21 for irrigated chickpea and 2.78 for dryland chickpea. The benefit to cost ratios in bean, lentil, irrigated chickpea and dryland chickpea farms were 6.18, 6.15, 3.71 and 8.10, respectively. Based on the results of the present study, dryland chickpea was the most efficient in terms of energy. Between studied irrigated crops, bean was the most efficient both in terms of energy and economical benefit. Keywords: Energy Productivity; Net return; Bean; Chickpea; Lentil JEL Classifications: O13; Q1; Q

Nitrogen release dynamics and carbon sequestration by legume and non-legume cover crops under pure and mixed planting conditions

Synchronizing crop residue decomposing and releasing nitrogen with subsequent cash crop needs provides benefits for ecosystems, but it is difficult to carry out. This study aimed to investigate the trend of decomposition of vetch (Vicia sativa), rye (Secale cereale) and mixed (rye + vetch) cover crop residues as well as nitrogen release after incorporating them into the soil during 12 weeks of the potato growth season by using the mesh bag method. Vetch residues decomposed very quickly in the spring and their nitrogen is released due to their higher nitrogen content and consequently a lower Carbon/Nitrogen (C/N) ratio. However, rye residues decomposed at a slower rate compared to mixed treatment, and their nitrogen content was immobilized mainly due to a higher C/N ratio. A better understanding of cover crops residues decomposition dynamics leads to maximizing the cover crop effects and higher nutrient uptake by subsequent main crops. The results of this study showed that the input level of nitrogen fertiliser can be reduced by implementing management strategies in farming potatoes and using cover crops, which will reduce the harmful environmental effects and increase the economic benefit for farmers

Efficiency of Chemical and Mechanical Priming in Breaking Seed Dormancy and Germination Traits of Malva (Malva neglcta)

Extended abstract Introduction: Malva (Malva neglecta) is one of perennial plants of the Malvaceae family. One of the most important mechanisms for survival of the plants is dormancy, rest or distance in germination and growth; in this case, despite favorable conditions for germination, the seed remains at rest for an indefinite period of time. Seed dormancy is a consistent feature in some seeds, especially weed seeds to optimize distribution of germination over time. Seed dormancy has a very important role in ecological management. The cause of the physical dormancy lies in skin cells outside tier structure that is impermeable to water. In physical dormancy, the seed coat is so hard that it does not allow the embryo to grow during germination. The chemical dormancy of the plants seeds is caused by the presence of inhibitor substances in the outer shell of many fruits and seeds and may also be due to an Enamel layer that blocks the exchange of oxygen. It goes without saying that understanding the ecology of weed germination and dormancy can contribute to long-term management. Therefore, this study was conducted to determine the effects of breaking seed dormancy and the impact of chemical and mechanical treatments on the germination of the Mallow seeds. Materials and Methods: In order to recognize the effects of chemical and mechanical treatments on breaking seed dormancy and some of the most important features of seed germination of Malva, the experiment was conducted based on a completely randomized design with 4 replications at Crop Physiology Lab, Razi University, during 2016. Treatments were distilled water (control), sulfuric acid 98% (for 2, 3 and 4 minutes), potassium nitrate 3% (for 3, 4 and 7 days), hydrogen peroxide 30% (for 2, 3 and 4 minutes) and scarification with sandpaper and prechilling (for 1, 2 and 3 weeks). Germination percentage, germination rate, length and dry weight of hypocotyl, length and dry weight of radicle, seedling total dry weight and vigor index were evaluated. Group comparisons, analysis of variance and comparison of means were run based on LSD at 5% level, using SAS software (version 9.4). Results: The results showed that the highest and the lowest germination percentage were 82% and 5% in scarification with a chilling for 3 weeks and control treatments, respectively. The results of treatment group comparisons also showed that using scarification with a chilling had the greatest impact on seed dormancy breaking. The most hypocotyl length (34.92 mm), hypocotyl dry weight (2.60 g), seedling dry weight (3.29 g) and seed vigor index (58.13) were observed in scarification with a chilling for 3 weeks. The highest germination rate (5.21 in day), radicle length (34.92 mm) and radicle dry weight (0.85 g) also belonged to sulfuric acid 98% for 2 minutes. It seems that seed dormancy of Malva was a combination of physiological and physical dormancy, because the effectiveness of the treatments evaluated in both metabolic and physical processes brought about the increase in the seed germination percentage. Conclusion: Out of the treatments examined and given the results of group comparisons, scarification with sandpaper and prechilling had the most effect on breaking Malva’s seed dormancy. As scarification with chilling had the main role in breaking seed dormancy, it could be said that the dormancy is physiological and factors contributing to this dormancy are the embryo, the existence of inhibiting factors or both. The results indicated that the germination of Malva (Malva neglcta) seeds mechanically scratched with scarification increased. Therefore, seed dormancy is due to hard coated seeds. The seed coat is as one physical barrier against growth of embryo or radicle that inhibits absorption of water and gas exchanges.     Highlights: 1- Investigating dormancy breaking and germination traits of neglcta species of Malva. 2- Evaluation of efficiency of different chemical and mechanical treatments in the germination traits of Malva

Evaluation of Tomato Production Systems in Terms of Energy Use Efficiency and Economical Analysis in Iran

Efficient use of energy helps to achieve improved production and productivity, and contributes to economy, profitability and competitiveness of agricultural sustainability. The aim of the present study was to compare open field and greenhouse tomato production systems in terms of energy efficiency, energy intensiveness, energy productivity, benefit to cost ratio and amount of renewable and non-renewable energy uses. Data were collected from 128 and 16 open field and greenhouse tomato growers, respectively, by using a face-to-face questionnaire in 2010. The results showed that the total energy requirement under open field and greenhouse systems were 47647.12 and 2102678.73 MJ ha-1, respectively. The share of direct, indirect, renewable and non-renewable energies from total energy input which average in open field and greenhouse production systems were 74%, 26%, 17% and 83%, respectively. Energy use efficiency was achieved 1.42 and 0.18 in open field and greenhouse, respectively. The benefit to cost ratios of 2.33 in open field and 3.06 in greenhouse was recorded. Based on the present results, open field tomato production system had higher energy efficiency in comparison with greenhouse tomato production system while greenhouse system had a higher economical benefit

Analyzing the energy balances of double-cropped cereals in an arid region

Efficient use of energy in agroecosystems will reduce environmental problems, prevent destruction of natural resources and serve to promote sustainable agriculture as an economical production system. The aim of this study was to investigate the energy use efficiency in four double cropping systems including: wheat–silage corn (W–SC), barely–silage corn (B–SC), barely–grain corn (B–GC) and barely–rice (B–R) in the arid regions of Isfahan province, Iran. Data used in this study were collected from 73, 45, 38, 18, 18 wheat, barley, silage corn, grain corn and rice farms, respectively, personal interview using semi-structured questionnaire during 2010. The results indicated that the total energy consumed were 140,422, 128,979, 121,360 and 172,962 MJ ha−1 for the W–SC, the B–GC, the B–SC and the B–R cropping systems, respectively. The share of diesel fuel by 43.36% (W–SC), 43.93% (B–GC), 42.82% (B–SC) and 49.40 % (B–R) was the highest input. This was followed by fertilizer (W–SC: 24.70%, B–GC: 25.12%, B–SC: 27.05 and B–R: 16.11) and water (W–SC: 10.54%, B–GC: 11.76%, B–SC: 10.73 and B–R: 13.85), respectively. The energy use efficiency was found as 1.70 for W–SC, 1.65 for B–GC, 1.64 for B–SC and 1.03 for B–R double cropping systems, respectively. According to the research results the W–SC, B–SC, B–GC and B–R double cropping systems were more efficient in terms of energy, respectively

Interaction Effect of CO2 Enrichment and Nutritional Conditions on Physiological Characteristics, Essential Oil and Yield of Lemon Balm (Melissa officinalis L.)

Carbon dioxide enrichment and nutritional improvement can increase photosynthesis and growth of different crops. The aim of the present study was to assess interaction effects of CO2 enrichment and fertilizer on physiological characteristics and lemon balm essential oil. Experimental units were composed of CO2 at 380, 700, and 1050 ppm with and without manure and N fertilizer application. A continuous increasing trend of individual plant leaf area, total dry weight accumulation and relative growth ratio were recorded with CO2 enrichment. When CO2 was elevated from 380 to 1050 ppm, the values of height (24.3%), SPAD reading (2.7%), essential oil yield (26.3%) and final yield (65.3%) were increased, unlike, stomatal conductance (35.2%) and essential oil percentage (53%) were decreased. The highest and the lowest values (except for oil percentage) were obtained under N and no fertilizer application, respectively. Except for SPAD, interaction between CO2 enrichment and each fertilizer on all measured characteristics had a significant effect, so that CO2 effect was intensified by applying each fertilizer. Therefore, it can be concluded that when temperature increase caused by rising CO2 is not considered or there is not a limitation for resources, CO2 enrichment will improve lemon balm biomass and essential oil yield

Evaluation of greenhouse gases emission based on energy consumption in wheat Agroecosystems

In order to have sustainable development, it is necessary to manage energy use and greenhouse gases (GHG) emission in all production processes. The aim of this study was to compare wheat production in dryland and irrigated agroecosystems in terms of greenhouse gases (GHG) emission based on energy consumption under different climatic regions. Data were collected from growers using a face-to-face questionnaire during 2013. The results showed that total energy consumption in irrigated and dryland wheat agroecosystems was 53082.9 and 15603.3 MJ ha−1, respectively. Energy use efficiency was 22.1% higher in dryland wheat agroecosystem than irrigated wheat agroecosystem. Total GHG emission for irrigated wheat agroecosystem was 3184.4 kg CO2-eq  ha−1 and 680.36 kg CO2-eq  t−1 while it was 553.1 kg CO2-eq  ha−1 and 381.3 kg CO2-eq  t−1 in dryland wheat agroecosystem. In irrigated wheat agroecosystem the highest GHG emission was 3561.8 kg CO2-eq  ha−1for arid–warm region and the lowest was 2832.6 kg CO2-eq  ha−1 for wet–moderate region. In dryland wheat agroecosystem the highest GHG emission was 584.2 kg CO2-eq  ha−1 for wet–cold region and the lowest was 523.01 kg CO2-eq  ha−1 for semiarid–warm region. In irrigated wheat agroecosystem diesel fuel had the highest emission (46.9%), followed by electricity (36.2%) and farmyard manure (7.5%). In dryland wheat agroecosystem the highest share of GHG emissions belonged to diesel fuels (75.8%), machinery (14.2%) and chemical fertilizers (8.5%), respectively

Pulses Production Systems in Term of Energy Use Efficiency and Economical Analysis in Iran

Energy analysis of agroecosystems seems to be a promising approach to assess environmental problems and their relations to sustainability. The aim of the present study was to compare bean, lentil, irrigated and dryland chickpea farms in terms of energy efficiency, energy productivity, benefit to cost ratio and the amount of renewable energy use. Data were collected from 18 bean, 27 lentil, 24 irrigated chickpea and 46 dryland chickpea growers, using a face-to-face questionnaire during 2010. The results revealed that the total energy requirement were for bean 23666.8 MJ ha-1, for lentil 14114.79 MJ ha-1, for irrigated chickpea 15756.21 MJ ha-1, and for dryland chickpea 2630.12 MJ ha-1. The average energy input consumed in studied crops including direct, indirect, renewable and non-renewable energies in bean, lentil, irrigated chickpea and dryland chickpea farms were 67%, 33%, 30% and 70%, respectively. Energy use efficiency was 1.81 for bean, 1.79 for lentil, 1.21 for irrigated chickpea and 2.78 for dryland chickpea. The benefit to cost ratios in bean, lentil, irrigated chickpea and dryland chickpea farms were 6.18, 6.15, 3.71 and 8.10, respectively. Based on the results of the present study, dryland chickpea was the most efficient in terms of energy. Between studied irrigated crops, bean was the most efficient both in terms of energy and economical benefit.Energy Productivity, Net return, Bean, Chickpea, Lentil

Influence of Weed Competition on Potato Growth, Production and Radiation Use Efficiency

Weed management in potato production is one of the main cost and time consuming practices. Understanding the most effective time of weed control could reduce the costs and increase potato yield. Field study was conducted in the west region of Iran during 2006 to evaluate the effect of weeds damage in potato fields. Twelve treatments used consisted of six initial weed-free periods in which plots were kept free of weeds for 0, 10, 20, 30, 40 and 50 days after crop emergence (DAE), and then weeds were allowed to grow until harvest, and six initial weed-infested periods in which, weeds were allowed to grow for 0, 10, 20, 30, 40 and 50 DAE, then the plots were kept free of weeds until harvest. Experiment was arranged as a randomized complete block design with three replications. The results showed effect of weed competition on crop dry matter started about 40 DAE and about 90 DAE reached its maximum. The weeds competition decreased dry matter accumulation, leaf area index, crop growth rate, leaf area index duration, light absorption, light extinction coefficient and radiation use efficiency (RUE) of potato. Weeds reduced the potato yield 54.8 percent. The beginning and the end of the critical period of weed control in potato (CPWC) was based on 5% and 10% tuber yield loss. The onset of the CPWC ranged from 486 to 572 GDD, at 5% and 10% yield loss level corresponding to 11 and 19 days after crop emergence, respectively. The end of the CPWC varied from 1372 to 1164 GDD, at 5% and 10% yield loss level corresponding to 65 and 51 days after crop emergence, respectively. RUE in the weed infestation treatment in comparison to the weed free treatment, reduced 11.8 percent