AGROECOLOGY (بوم شناسی کشاورزی)
Year:2016 | Volume:8 | Issue:3|Papers Count:11

Introduction: In conventional crop management systems fields are considered as a homogenous environment however, because of high within field spatial variability such management is economically inefficient and provides drastic environmental consequences (Pierpaoli et al., 2013). Crop yield at any point of a field is a function of factors including planting density, weather conditions, management practices and biotic and abiotic stresses which results to spatial variability. Understanding the pattern and determinants of yield variability provides a basis for development of site specific management systems with lower inputs (Basso et al., 2012). In this study spatial variability of soil nitrogen, weed density and their effect on crop yield variation within a wheat field are surveyed and mapped using geostatistical methods. In addition the effects of sampling distance on the accuracy of results were evaluated.Materials and Methods Required data were collected from a 3.5 ha wheat field which was fully managed by owner based of local agronomic recommendations. Samples were taken from a 90×120 m area located in the field center and divided into 10×10 m grids. Soil nitrogen content and weed density at tillering and wheat yield at maturity were measured in 1 m2 plots located at the center of each grid. Semivariogarms were developed after fitting spherical model to the calculated semivariance for each spatial variable. Simple kiriging was used for spatial interpolation and mapping spatial variability of soil nitrogen, weed density and wheat yield and co-kriging was applied with soil nitrogen or weed density as covariates to map within field yield variation (Goovaerts, 1999; Oliver and Webster, 2014). The same analysis was repeated with 20×20 m grids to evaluate the effect of sampling distance.Predictions results were validated against measured values using standard statistical methods.GS Plus (γ-Design) ver.9.0 was used for geostatistical analysis and mapping.Results and Discussion Grain yield was varied between 1.5-4.9 t ha-1 with coefficient of variation (CV) 0f 29%. However, weed density and soil nitrogen showed a higher spatial variation with CV of 55 and 41%, respectively. Based on the results of multiple regression, weed density and soil nitrogen accounted for 80% of the observed yield variation.Semivariance was calculated for the studied variables with 10 and 20 m lag distances and spherical model was fitted to the experimental variograms. Comparison of statistical characteristics of the variogram models indicated that precision was decreased with increasing sampling distance. Based on the modeled variograms measurements were interpolated using ordinary kriging and the resulting yield maps were reasonably mached with spatial pattern of soil nitrogen and weed density. The accuracy of interpolated yields with kriging at 10 and 20 m sampling distance was validated against the observed yields. Yield prediction accuracy was improved with cokriging particularly when soil nitrogen content was defined as covariate in both distances however, this method of interpolation was more efficient at 10 m sampling distance.Conclusion Based on the results it was concluded that spatial variability of wheat yield could be mapped with good accuracy using simple kriging when sampling distance is 10 m or lower. However, at 20 m sampling distance accurate yield maps were obtained after co-kriging with covariates such as soil nitrogen or wee density which arehighly correlated with yield. Spatio-tempral yield variation could be studied by repeating such an experiment in different years.

Introduction Roselle (Hibiscus sabdariffa L.) as a medicinal plant belongs to the Malvacea family. Their active ingredient increases under water stress. Humic acid bacteria derived from humus and other natural resources have hormonal effects and can improve nutrient absorption to enhance performance especially under stress conditions.Materials and methods This experiment was conducted in the research of agricultural education centre Jiroft in 2013. Field experiment was carried out as split plot design with three replications. Water deficit stress set as main factor with three levels (A1=Irrigation after 50, A2=100 and A3=150 mm evaporation from pan class A) and humic acid was in four manners (B1=non humic acid, B2=once with Irrigation, B3=once with Irrigation+Once spraying, B4=once with Irrigation+twice Spraying). Humic acid was used to form Irrigation spray in order to arrange with compactness (10 kg.ha-1), (250 ml/100L). In late September, which coincides with the end of the heading, plant height, inflorescence length, number of branches, stem diameter, fresh and dry weight of plant, fresh and dry weight of sepals, were examined. Wagner method was used to measure anthocyanin content sepals (Wagner, 1979). Finally, data was analyzed using SAS 9.1 and means were compared by Duncan’s multiple range test at 5% level of probability.Results and discussion The analysis of variance showed that drought stress and humic acid had significant effect on growth parameters, vegetative and generative yield and anthocyanin. Drought stress decreased plant height, inflorescence length, stem diameterand fresh and dry weight sepals. The highest values of these traits was obtained in the first level of stress (50 mm evaporation from pan class A). Due to the reduction in mentioned properties, reducing the pressure tolerance and the subsequent reduction in drought conditions was considered as division and cell enlargement. The reduction in growth parameters by drought stress can be due to disorder in photosynthesis and reduction in photosynthetic. The impact of drought on each of growth parameters could finally lead to a change in the performance of the roselle calyx production.Drought stress increased anthocyanin content. The highest phenolic compounds anthocyanins (0.49μmol.g1) was obtained in three level stress (150 mm evaporation from pan class A). Antioxidant flavonoids had protective effect during drought stress and due to the role of anthocyanin in protection from sun during oxidative stress, ROS was directly removed. The results showed a significant interaction between stress and humic acid on number of branches, fresh and dry weight of plants. The highest value of these traits treatment was observed in first level stress (irrigation after 50 mm evaporation from pan class A) and in four level of humic acid (once with irrigation+twice spraying). Plant height, inflorescence length, stem diameter, fresh and dry weight of sepals and anthocyanin were significantly affected by humic acid. The highest value of these traits was obtained in four humic acid (once with irrigation+twice spraying). Humic acid can reduce the effects of drought, increase absorption of water and nutrient and the growth of plants by physiological changes in plant and by improving the physical, chemical and biological characteristics of soil, in order to improve growth parameters, vegetativeand generative yield and anthocyanin in the experiment.Conclusion Sufficient moisture in the soil and high genetic potential for optimum usage of the potential environment are essential for plants. The amount of humic acid due to its role in improving the nutritional conditions of the plant can play an important role in offseting the harmful effects of drought stress on the plant.

Introduction: Half of the world's population suffers from micronutrients malnutrition. Use of bio-fertilizers in sustainable agricultural systems is important in production and enables plants to absorb more water from soil and improves plant nutrient uptake and photosynthesis. Benefits of vermicompost application in agriculture is due to its content of organic matter, plant nutrients and plant growth promotion. Vermicompost increases the absorption and transition of nutrients from soil to roots and improves plant growth (Simsek-Ersahin, 2011). Zn and Fe application is highly important; foliar application causes faster and higher absorption rate and cures deficiencies symptoms (Ghaffari et al., 2010).Thiobacillus is a chemolithotroph bacterium, receiving energy from sulfur oxidation. This bacterium acidifies microcites in the rhizosphere, increasing the availability of nutrients to plant roots (Kaya et al., 2009). Regarding the benefits of integrated nutrient management, this experiment was conducted with the aim of testing the effects of Fe and Zn foliar spraying, Thiobacillu sthiooxidans inoculation and vermicompost application on growth, yield and bio fortification of popcorn maize.Materials and methods This experiment was conducted in 2012 at the research field of Islamic Azad University, Tabriz branch, Iran.The experiment was conducted in factorial in the form of a randomized complete block design with three replications and four factors: vermicompost application in soil (0 and 2 t.ha-1, applied in strip form below the seeds before cultivation), inoculation withThiobacillus thiooxidans, with a population of 108cfu.g-1. Sulfur was inoculated with T. thiooxidans prior to application. Fe chelate foliar application (without spraying and two times spraying of 0.002 concentration of 13% Fe chelate) and Zn chelate foliar application (without spraying and two times spraying of 0.002 concentration of 15% Zn chelate). Maize seeds (Zea mays L. var. popcorn KSC.600) were planted, after being inoculated withAzospirillum, at the rate of 66, 000 plants. ha-1. Then, 10 plants were harvested from the middle rows of each plot and grain yield was measured. To measure the absorption of nutrients, 5 other plants were harvested from each plot when grains were at dough stage and dried at 70°C oven for 72 hours. Then, samples were grinded and analyzed. Finally, data were tested for normal distribution and subjected to statistical analysis using SAS. Duncan's multiple range tests was used to compare means at p£0.05.Results and discussion Results indicated the significant effect of vermicompost on 1000 kernels weight, the number of kernels/ear, stem height, stem diameter, grain yield, biologic yield, Fe, Zn and protein contents. The effect of Thiobacillus inoculation was significant on all measured traits except for the stem height. Fe foliar application significantly affected stem height, biologic yield, grain yield an Fe content. Zn foliar application had also a significant effect on the number of kernels/ear, stem height, grain yield, Zn content and protein content. Results of this experiment generally indicated that application of vermicompost, Thiobacillus, Fe and Zn had improving effect on maize yield, yield components and grain quality.Conclusion Nutrient management is one of the most important factors in successful crop production, so, it was tried inthis experiment to take advantages from soil microorganisms to find a suitable method for sustainable crop nutrient management instead of chemical methods. In recent years, increased application of chemical inputs to agricultural fields has caused several environmental and health issues and reduced the quality of products. So, as the results of this experiment showed, integrated nutrient management with lower dependency on chemical fertilizers is a promising method to reach sustainable and healthy production and food safety.Acknowledgement The authors highly acknowledge Islamic Azad University, Tabriz Branch- Iran, for their fields and laboratories support.

Introduction: Crop sequencing with a particular arrangement in a 2-3 or more yearly period is known as crop rotation.Considering crop diversity and soil fertility crop rotation is essential because it prevents soil degradation which is a result of sequential cultivation of one crop causing nutrients imbalance, exudation of different compounds and antibiotics from crop roots. Determining crops sequencing, affects crops yield and its quality. It was reported by many researchers that including the forage crops and legumes as a winter crop in rotation either for forage production or green manuring, i.e. growing two or three crops annually was a necessary practice for improving the soil fertility as well as increasing the annual revenue. So, this study was conducted to investigate effects of different crop rotations on grain yield and some agronomic traits of wheat in dryland conditions.Materials and methods The experiment was carried out based on randomized complete block design (RCBD) with four replications in two neighbor sites in dryland agricultural research sub-institute Sararood - Kermanshah during six years from autumn 2006 fall to 2012 summer. Treatments were concluded five crop rotations as wheat(Triticum aestivum L.) - wheat, fallow - wheat, chickpea (Cicer arientinum L.) - wheat, vetch (Vicia dasycarpa Ten.) - wheat and safflower (Carthamus tinctorius L.) - wheat. All crop rotations were included wheat so in one site the first year wheat was cultivated in all plots and in other site the other components of crop rotations were cultivated. Plot area was 10×20 m2. Plant height (10 randomized plants), number of spikes per meter square, number of seeds per spike, thousand seeds weight, biologic yield and grain yield were analyzed.Results and discussion Main effect of year on wheat plant height and yield components were significant and showed different climatically conditions in experiment years. Interaction effect of rotation × year was significant on wheat plant height and number of spikes per m2, and in the end of rotation period (2011-12) effect of continuous wheat appeared on number of spikes per m2 as in this year the lowest number of spikes per m2 in continuous wheat observed compare to other rotations. Ghaffari (2002) considered the rotation of chickpea, sunflower (Helianthus annuus L.) and fallow with wheat and reported no significant effect on plant height of wheat in three period of rotation. The results of thousand kernel weight showed non significance difference among rotations and year × rotation interaction that were similar to results of Dogan et al. (2008) in two rotation period of wheat and sunflower, canola (Brassica napus L.), chickpea and forage pulses. Results of composite ANOVA for biologic and grain yield of wheat showed significant effect of year and treatment × year on these traits; and continuous wheat had the lowest yield and other rotations were located in higher classes. Continuous wheat treatment at the last year had the lowest spikes per meter square among rotations. Stevenson and Kessel (1996) stated an increasing trend in wheat grain yield in pea (Pisum sativum L.) – wheat rotation compared to continuous wheat due to breaking of diseases cycles and availability of potas, phosphorous and sulfur. Correlation between wheat grain yield in different rotations with total precipitation showed that in all rotations except continuous wheat, there was a positive significant correlation between precipitation and wheat grain yield. So, it can be concluded that continuous wheat has reduced the potential usage of optimum growing conditions.ConclusionRotation of wheat with each of these crops (chickpea, vetch and safflower) can be proposed, considering the importance of crop diversity and additional yield of these crops.

Introduction: In agronomy, natural outlook has been expressed in different forms which stable agriculture is an example.Stable agriculture is ascribed to the authentic management of agricultural resources, which in addition to fulfilling the ever-changing needs of humans, maintains the health of environment and capacity of water and soil resources. Application of herbicides, besides being costly, resulted in the selection of herbicide resistant weed species and has become an environmental contamination factor. However, reduction of herbicide consumption is one of the goals of modern agriculture, with several methods being suggested, including intercropping. In natural conditions of production, environment conservation of weed existence requires cost. One of the important preparations in weed control from the perspective of sustainable agriculture, is using intercropping system. The aim of this study was to determine the role of crop diversity on weed and crop production based on the beneficial effects of intercropping system than pure.Materials and methods In order to study effects of mixed and sole cropping of barley with common vetch on their biologic yield and utilization indices, an experiment was conducted in Agricultural college of the University of Lorestan, during the growing season of 2013-2014 with 24 treatments using the method of rows replacement series technique by the randomized complete block design in a factorial arrangement with three replications. First factor included 6 levels of intercropping: sole cropping of common vetch (100%), 55-45 (Common vetch-barley), 35-65, 45-55, 65-35 and sole cropping of barley and second factor included 4 levels of weed wild safflower, control, 10, 15 and 20 plants per m2. In this experiment WCE, LER and CR were measured. The data were subjected to analysis of variance (ANOVA) using Mstat-C computer software. Mean comparisons were performed using Duncan’s multiple range test at two levels of significant 1% and 5%.Results and discussion There was significant difference between minimum and maximum dry weight of weeds, the results showed that barley have important role in weed control wild safflower. Therefore, weed control efficiency in 15 plant in m2 was higher than two 10 and 20 plant in m2. The lowest WCE (161.27%) was found at 15-35-65 treatment, but, the highest WCE (51.99) was obtained from 15-65-35 (Wild safflower-common vetch-barley) treatment.Computes showed that WCE, in 15 plants of wild safflower/m2, was more than 10 and 20 p/m2. The reduction in weed population and biomass in intercropping systems with barley may be attributed to shading effect and competition stress created by the canopy.Thus, result showed that reduction rate of common vetch in intercropping, with bearing compatibility power to weeds reduced LER. CR for common vetch intercropping component in comparison with barley in total treatments was>1. The highest CR, for vetch obtained from treatment 45-55-control (2.64) and for barley from seed ratio 65-35-control (1.83).Conclusion The results in this study showed various seed rate had noticeable effect on forage yield, LER and weedcontrol. In this experiment changing seed rate in two tested plants (barly- commen vetch) changed the number and weed species, as a result noticeable changing was created in their competitive power. Result showed that seed rate (35% barley-65% common vetch) was better than other treatment, not only in use efficiency of environment, but also it had more dry forage yield. Also, former seed rate had effective role in decreasing the weed biomass. This important result was related to reduced light penetrate at the bottom of cover crop and probably lack of competition in access to environmental resources was also affected. So using this seed density for mentioned area is recommended for reducing weed competition and improving the quality and quantity of dry forage.Acknowledgments The authors gratefully acknowledge the teachers of College of Agriculture of Lorestan University, for their critical review of the manuscript.

Introduction: Various factors like climatic conditions, vegetation, soil properties, topography, time, plant residue quality and crop management strategies affect the decomposition rate of organic carbon (OC) and its residence time in soil. Plant residue management concerns nutrients recycling, carbon recycling in ecosystems and the increasing CO2 concentration in the atmosphere. Plant residue decomposition is a fundamental process in recycling of organic matter and elements in most ecosystems. Soil management, particularly plant residue management, changes soil organic matter both qualitatively and quantitatively. Soil respiration and carbon loss are affected by soil temperature, soil moisture, air temperature, solar radiation and precipitation. In natural agro-ecosystems, residue contains different concentrations of nitrogen. It is important to understand the rate and processes involved in plant residue decomposition, as these residues continue to be added to the soil under different weather conditions, especially in arid and semi-arid climates.Material and methods: Organic carbon mineralization of alfalfa residue with different nitrogen concentrations was assessed in different climatic conditions using split-plot experiments over time and the effects of climate was determined using composite analysis. The climatic conditions were classified as warm-arid (Jiroft), temperate arid (Narab) and cold semi-arid (Sardouiyeh) using cluster analysis and the nitrogen (N) concentrations of alfalfa residue were low, medium and high. The alfalfa residue incubated for four different time periods (2, 4, 6 and 8 months).The dynamics of organic carbon in different regions measured using litter bags (20×10 cm) containing 20 g alfalfa residue of 2-10 mm length which were placed on the soil surface.Results and discussion The results of this study showed that in a warm-arid (Jiroft), carbon loss and the carbon decomposition rate constant were low in a cold semi-arid (Sardouiyeh). The most suitable temperatures occurred from April to October in arid and semiarid climates and soil moisture is probably the key contributor to the rate of decomposition. The highest carbon loss in alfalfa in the cold, semiarid climate for a period of 8 months was 32.64%. The highest carbon decomposition rate constant was observed in the first 2 months of the incubation time. These results indicate that higher nitrogen residue resulted in greater decomposition of plant residue and lower carbon remaining in all tested climates. The higher nitrogen content of plant residue potentially increases the concentration of nitrogen in crop residue and may increase the decomposition rate.The strong relation between decomposition and climate has led to the belief that favorable climatic conditions can increase the decomposition rate on a global scale and positively decrease and distribute greenhouse gases in the atmosphere. In arid and semi-arid ecosystems, it is difficult to assess the decomposition rate based on climatic data; it seems to be related to temperature and available humidity. Furthermore, Austin & Vivanco (2006) reported that, in semi-arid climates, the litter decomposition rate decreased by 60 % when solar radiation was attenuated; they concluded that photodegradation exerts dominant control over litter decomposition in a dry ecosystem.Conclusions: The results showed that, precipitation of the study area and soil moisture played a key role in the plant residue decomposition rate. In the cold semi-arid climate which moisture was available for decomposition of plant residues for a longer period of time, OC loss and decomposition rate constant were higher than those obtained for warm-arid and temperate-arid climatic conditions. It may be concluded that crop fertilization, which increases P and N concentrations of plant residue, increases decomposition rate of plant residue but decrease its mean residence time in soils.

Introduction: Amount and vertical distribution of leaf area are essential for estimating interception and utilization of solar radiation of crop canopies and, consequently dry matter accumulation (Valentinuz & Tollenaar, 2006). Vertical distribution of leaf area is leaf areas per horizontal layers, based on height (Boedhram et al., 2001). Aboveground biomass is one of the central traits in functional plant ecology and growth analysis. It is a key parameter in many allometric relationships (Niklas & Enquist, 2002). The vertical biomass distribution is considered to be the main determinant of competitive strength in plant species. The presence of weeds intensifies competition for light, with the effect being determined by plant height, position of the branches, and location of the maximum leaf area. So, this experiment was conducted to study the vertical distribution of leaf area and dry matter of soybean canopy in competition with weeds and cover crops.Materials and methods: This experiment was performed based on complete randomized block design with 3 replications in center of Agriculture of Joybar in 2013. Soybean was considered as main crop and soybean and Persian clover (Trifolium resupinatumL.), fenugreek (Trigonella foenum - graecum L.), chickling pea (Lathyrus sativus L.) and winter vetch (Vicia sativa L.) were the cover crops. Treatments were included cover crops (Persian clover, fenugreek, chickling pea and winter vetch) and cover crop planting times (simultaneous planting of soybean with cover crops and planting cover crops three weeks after planting of soybeans) and also monoculture of soybeans both in weedy and weed free conditions were considered as controls. Soybean planted in 50 cm row spacing with 5 cm between plants in the same row. Each plot was included 5 rows soybeans. Cover crop inter-seeded simultaneously in the main crop. Crops were planted on 19 May 2013 for simultaneous planting of soybean. The dominant weed species were green foxtail (Setaria viridis L.), foxtail grass (Alopecurus myosuroides Huds), and red root pigweed (Amaranthus retroflexus L.) in the experimental field. The other weed was considered as the others. At the soybean canopy closure stage, a vertical card board frame marked in 20-cm increments was used in the field as a guide to cut standing plants including soybean, cover crops and weeds. In each vertical layer of canopy, leaves and stem samples were separated. The leaf area both crops and weeds were measured with a leaf area meter LICOR-3000A (LI-COR, Lincoln, NE, USA). Stem and leaf samples oven dried.Results and discussion: The results showed that the maximum leaf area and dry matter of soybean was varied in different layers of canopy depending on the type of cover crop and cover crop planting time, while delaying in planting of cover crop causes lower leaf area and dry matter than the plants were planted at the same time with soybean. In most cases, the maximum leaf area index and dry matter accumulation of weeds were obtained in primary layer (0-20 cm). The maximum weed leaf area (290.4 cm2) was observed in simultaneous planting of soybean with fenugreek and maximum of total weed dry matter (12.4 g.plant-1) was observed in soybean without weeding, while the minimum of weed total leaf area and total weed dry matter (0 cm2 and 0 g.plant-1, respectively) was achieved in planting of winter vetch after 21 days of soybean planting. Also delayed planting of winter vetch produced the maximumgrain yield (3792.6 kg.ha-1) of soybean in weedy plots, where it had the greatest weedsuppressive ability than other cover crops.Conclusion: Winter vetch can suppress weed with competition and allelopathic mechanism, so we can conclude that winter vetch planting21 days after soybean planting is suitable replacement for weed suppression in sustainable agriculture.

Introduction: Saffron as a winter active plant with low water requirement is the most strategic medicinal plant in arid and semi-arid parts of Iran. This slow-growing plant has narrow leaves and no aerial stem, hence weeds can be overcome it. Moreover, because of its root and canopy structure an important part of different resources is not used by this low input crop. Therefore, the use of associated crops could be an effective way for increasing resources use efficiencies (Koocheki et al., 2016). Appropriate corm planting date is another important factor that affects saffron growth and yield. Results of some studies show that late spring is the best time for corm planting (Ghasemi-Rooshnavand, 2009; Koocheki et al., 2016). In addition, irrigation management has been evaluated in some studies, but irrigation immediately after corm planting has not been investigated previously.Therefore, the aim of this study was to investigate the effect of irrigation management, planting date and the use of some companion crops on flowering of saffron during two growth cycles.Materials and methods This experiment was carried out as a split-split plot experiment based on a Randomized Complete Block Design with three replications at Research Station, Ferdowsi University of Mashhad, Iran in 2009-2011.Experimental factors included: planting date of saffron as main factor (first of June, first of August and first of October, 2009), the irrigation management as sub factor (irrigation and no irrigation after each planting date) and the companion crops as sub-sub factor [Persian clover (Trifolium resupinatum), Bitter vetch (Lathyrus sativus) and control). Corm planting was done in 10×25 cm distances with 12 cm depth. In the second year irrigation was done again in the plots which were irrigated after planting in the first year at the same previous dates.Companion crops were sown after first flower picking (November, 2009), then their residue were returned to the soil in coming spring (May, 2010). Therefore, data were analyzed as split-plot in the first year and split-split-plot in the second year. Data analysis was done using SAS 9.1 and means were compared using Duncan multiple range test in 5% level of probability.Results and discussion Results showed that most growth and flowering indices of saffron were significantly affected by experimental factors. Quantitative indices of saffron were decreased considerably by delaying in planting date in both studied years. The highest flower yield was obtained in June planting date (28 and 98 kg.ha-1 in 2009 and 2010, respectively), while the lowest was shown in October planting date (18 and 34 kg.ha-1 in 2009 and 2010, respectively). Enhanced growth and yield of saffron in spring planting date is because of real dormancy stage of corms in this time. All studied indices were superior in no-irrigated treatments after planting in both studied years. The flower yield was 9 and 43 kg.ha-1 in 2009 and 2010 in irrigated treatments, respectively, while these values were 37 and 78 kg.ha-1in 2009 and 2010 in no-irrigation treatment, respectively. It has been reported that irrigation during the creation of the primary leaves in the corm buds is negative, while irrigation after this period and simultaneous with the beginning of primary reproductive organs creation is suitable for saffron flowering.The application of cover crops improved partially the quantitative indices of saffron, particularly in Bitter vetch treatment. In addition, the highest flowering rate and the lowest leaf appearance rate were observed in June planting date, no-irrigation and Bitter vetch cover crop treatment. The positive effects of short-growth cyclecompanion crops on saffron is related to improvement of soil physical, biological and chemical properties, soil temperature regulation, prevention from nutrient leaching, N-fixation by Fabaceae species and help to weeds control.Conclusion: In total, saffron corm planting few days after the falling leaves in spring, no-irrigation after corm planting, avoidance from untimely summer irrigation and the use of appropriate winter cover crops are good strategies for saffron production.

Introduction: Pistachio (Pistacia vera L.) is one of the most important export crops of Iran which has an important role in non-petroleum exports and has over $800 million benefit per year. However, production of this crop faces many problems in main production centers, especially in energy efficiency and productivity. The pistachio is a native crop of Iran and Syria. The major producers of pistachio are Iran 55%, America 20%, Turkey 10%, Syria 9% and the other countries with 6%. Iran is the major producer of pistachio in the world with more than 60 % of global exports. Kerman Province with more than 270, 000 ha under cultivation produces 77 percent of this crop.Moreover, Zarand county with more than 45, 000 ha under cultivation plays a major role in the production of pistachio.Energy flow is one of the topics of agro-ecology in the world and energy output to input ratio is calculated in various agro-ecosystems. One of the indicators of agricultural development is energy flow. So, different studies in the world have been done to evaluate the energy efficiency in the agro-ecosystems. Studies on apricot (Armeniaca vulgris Lam.) showed that energy efficiency can increase with appropriate management practices with minimum dependence on non-renewable energies.Energy consumption is divided into two parts in agriculture: direct and indirect energy. Direct energy is the fuel, machinery, electricity, energy required for cooling, heating, and lighting. Indirect energy includes the energy used in the production of fertilizers, seed production, machinery, and pesticides. Energy efficiency is an important factor in increasing productivity, especially in agricultural economy of developing countries.Although, many studies have been carried out on energy consumption in the agricultural systems, the analysis of the energy input required to produce pistachio is very low.Therefore, the objectives of the present study were to determine the input and output energy rates, energy use efficiency, and other energy-related factors in the production of pistachio in Zarand county of Kerman province.Materials and methods This research was conducted in the spring of 2011 in the county of Zarand. Zarand is located in the northwestern province of Kerman. In this study, some producers were selected and primary information was collected using questionnaire directly. All data (input and output) were converted to energy equivalent quantities and then energy efficiency was calculated. Random sampling was done in gardens within whole population and sample size was determined by Ozkan et al. (2004).Where n is the required sample size, N is the number of holdings in target population, s: standard deviation, t is the reliability coefficient (1.96 which represents the 95% reliability) and d is permissible error (5%).Basic information on energy inputs and pistachio production were transferred into Excel spreadsheets, and analyzed. Based on the energy equivalents of the inputs and output (Table 1), the energy ratio or energy use efficiency, energy productivity and net energy were calculated: Energy efficiency=Energy input (MJ. ha-1) / energy output (MJ. ha-1) Energy productivity=Energy input (MJ. ha-1) / pistachio production (kg. ha-1) Net energy=Energy input (MJ. ha-1) - Power output (MJ. ha-1) Results and discussion The results showed that total input energy forPistacia vera L. production was 119423 MJ. ha-1, whereas total output energy was 40950 MJ. ha-1. Energy efficiency, energy productivity, and net energy were 0.34, 0.012 kg.MJ-1 and -78474 MJ.ha-1, respectively. The highest input energies were related to electricity (45%) and fossil fuels (20%) which had the highest effect on decreasing energy efficiency. Economically, the total cost of Pistacia veraL. production per hectare was 57469600 and the net benefit was 6253040 Rials.Conclusion It was concluded that extending proper agricultural management and sustainable exploration of natural resources can enhance energy consumption efficiency in Pistacia vera L. production. Moreover, due to the shortage water and the critical situation of the aquifers in this region, city regional water management should consider measures to reduce water consumption and improve the distribution of water between the farmers to help the sustainability of the aquifers and more efficient production.

Introduction: Water shortage in Iran has always been a limiting factor for crop cultivation. Drought stress at different growth stages, especially flowering and grain filling stages decreases the yield of the plants. Drought stress may limit yield of medicinal and aromatic plants by reducing the harvest index (HI). This can occur even in the absence of a strong reduction in total medicinal and aromatic plants dry matter accumulation, if a brief period of stress coincides with the critical developmental stage around flowering stage. Water stress is the most influential factor affecting crop yield particularly in irrigated agriculture in arid and semi-arid regions. It is necessary to get maximum yield in agriculture by using the least available water in order to get maximum profit per unit area because existing agricultural land and irrigation water are rapidly diminishing due to rapid industrialization and urban development. In general, 15% of the Iran lands are saline and sodic (Parsa, 2000) and it dues to the use of widespread of water resources and the soil salinity of the farms. Unfortunately this factor (soil salinity) gradually becomes more serious, in fact even in none-saline water irrigation with salt accumulation in the soil in long period of time it may increase and the result will be the limitation of the products (Sharma, 1996). The analyzing of the growth and product is a method for discovering the factors which are effecting on the plants. The purpose of the analyzing of the plants growth is the reaction of the plants to the environmental factors (Sangwan et al., 1994). Cumin (Cuminum cyminum) is one of the most important economic and medicinal plants that can growth in arid and semi-arid conditions. Cumin is mostly grown in China, Uzbekistan, Tajikistan, Iran, Turkey, Morocco, Egypt, Syria, Mexico, Chile and India. In the ancient Egyptian civilization cumin was used as spice and as preservative in mummification. The purpose of this study was the effect of drought and salinity in different phenological stages on some of the growth characteristics of cumin cultivars.Material and method The experiment was split plot in a randomized complete block design with three replications, in Ferdowsi University of Mashhad, Iran during growing season of 2008-2009. Factors were including irrigation times (I1: one times irrigation, I2: two times irrigation I3: three times irrigation and I4: four times irrigation (control) and with two levels of salinity stress (irrigation with normal water and saline water five dS.m-1) and two cumin cultivars (Sarayan, Indian cultivar RZ 19). To determine the physiological properties of cumin every 14 days five plants from the bottom half of each plot was randomly picked and transferred to the laboratory and some specifications such as green area, plant dry weight and the number of side branches was measured. For Data analysis software Mstat-C was used. The growth parameters were calculated and graphs were drawn by Excel software.Results and discussion Dry weight variations were significant by increasing irrigation. The highest amount of dry weight for treatment with three times irrigation (260 g.m-2) and the lowest amount for one time irrigation (193.5 g.m-2) were recorded. Salinity too causes decline dry weight in such treatments that dry weight with the use of normal water was 252 g.m-2 and with saline water was 199.6 gr/m-2. In the various experiments conducted on cumin, it was found that the process of creating green area in this plant is slow, especially in the early period. According to various sources, maximum green area index for cumin not exceed the greater of 1.5 and for a large part of growing season is less than one. One time irrigation treatment showed the lowest green area index. The highest CGR was in three times irrigation with 7.92 g.m-2.day-1 and the lowest CGR was in one time irrigation with 4.87 gr.m-2.day. Leaf area index duration increased with more irrigation. Green area index duration was 15.63 m2 leaf.m-2 land in three times irrigation and By reducing irrigation frequency has been significantly reduced.Conclusion In this experiment, all of the growth indices were affected by drought and salinity. The lowest specifications were in one and four irrigation times with saline water. Also between Sarayan and Indian cultivar, Sarayan was better than Indian cultivar under salinity condition.

Introduction: Agricultural research is important and one of the determinant factors of development of technologies in agricultural sector. Among agricultural research disciplines, breeding programs, especially, wheat breeding programs are one of the applied approaches in improving of production and food security. Based on a study by Byerlee & Traxler (1995), economic benefits and Internal Rate of Return (IRR) for Impact of International Wheat Improvement (for all breeding programs) were estimated US$3.0 billion per year with internal rate of 53%, and economic benefits for Impact of International Wheat Improvement (Attributed to IWIN) was estimated US$1.5 billion per year during 1966-90.Materials and methods The main objectives of this research were to determine shift of supply function of variety and impacts of breeding wheat varieties on reduction costs, and determination of economic return of released irrigated bread wheat in breeding program for the period of 1991-2000. Wheat varieties included; 23 varieties of released irrigated bread wheat by wheat breeding program of Seed and Plant Improvement Institute (SPII) and Provincial Agricultural Research Centers. Ex-ante and Ex-post methods were used in this study. Measuring criteria for these methods were; quantity of shift in supply function, cost-benefit analysis and internal rate of return of varieties.For estimation of reduction costs and shift of supply function of varieties in breeding program were calculated following Brennan et al. (2002).