نشریه بوم شناسی کشاورزی
سال سیزدهم شماره 3 (پاییز 1400)

Intercropping is highly recommended to be used in many parts of the world for food or fibers productions, because of its overall high productivity. Intercropping consists of growing two or more crops together at once, even though the crops are not sown or harvested simultaneously. The success of intercropping is due to an enhanced temporal and spatial complementarity of resource capture. Many studies have reported that intercropping can increase crop yield due to efficient utilization of nutrients and light, and enhanced positive interactions between crops. Features of an intercropping system can differ with soil conditions, climate, economic situation, and preferences of the local community. In this study, we carried out a two-year field experiments to evaluate yield and yield components as well as growth indices in cotton and maize grown in an alternative intercropping systems.

The experiment was carried out based on a randomized complete block design at Gonabad Agricultural and Natural Resources Research Station. The cotton (Khordad cv.) and maize (D.C 370) plants were evaluated using an alternative intercropping system. The treatments consisted of one row of cotton along with one row of maize, two rows of cotton along with one row of maize, three rows of cotton along with one row of corn, and pure cotton and maize cropping. The seeds were sown 20 cm apart in the rows in May. Irrigation was performed every 10 days and monitored using a volumetric flow meter. Twenty days after emergence, sampling was carried out by harvesting three plants of each species to measure growth indices such as plant height, leaf rea index and dry weight. At the end of growing season the crops were harvested and yield and yield components were determined. The data were analyzed by using SAS 9.1 software.

The effect of intercropping was significant on maize seed and forage yield. Since plant density in intercropping treatments was less than pure culture, the maximum maize seed and forage yields were obtained from pure culture treatment. By contrast, the minimum seed and forage yields were related to one row maize along with two rows cotton treatment. Reduction in maize biological yield due to intercropping was reported by Khorami-Vafa (2006), Tuna and Orak (2007) and Patel et al., (1999). Three rows cotton along with one row maize treatment produced the maximum maize seed and forage yields. Yield increasing in this treatment may be due to more space between maize plants, providing more light and reducing intraspecific competition. No significant difference was found between intercropping treatments in terms of cotton yield. The maximum cotton yield was obtained from cotton pure cropping, whereas, the minimum yield was related to one row cotton along with one row maize treatment. Amongst intercropping treatments, the maximum cotton yield was obtained from two rows cotton along with one row maize treatment. The increase in maize and cotton biomass followed a similar trend in both years. The maximum reproductive and vegetative branches, dry matter and leaf area index were related to two rows cotton along with one row maize treatment. The maximum maize leaf area was related to three rows cotton along with one row maize treatment. In general, dry matter accumulation linearly increased 30 days after seed sowing in both maize and cotton plants and reached to its maximum 60 days after seed sowing and then started to decrease due to leaf senescence and abscission. Furthermore, in both species, leaf area index reached to its maximum 69 days after seed sowing and then started to decrease due to canopy closure, shading, leaf senescence and abscission. Mukhala et al, (1999) and Koocheki et al, (2010) have shown intercropping cause a significant increase in leaf area index.

Generally it is concluded that maize and cotton yield in intercropping treatments were higher also traits such as leaf area index and dry matter accumulation in one row maize along with three row cotton was higher than other treatments.

In general, management methods applied at the agroecosystems, can affect the population and activity of micro and macro organisms. In high input farms, which use especially large amounts of chemical inputs, it has destructive effects on soil agroecosystems and soil organisms. Soil is an essential component of agricultural systems and the key to soil fertility is to preserve the biodiversity of the soil ecosystem. Microorganisms are the main factor in advancing ecological processes in ecosystems, and soil microbial processes affect the functioning of ecosystems such as nutrient rotation, soil fertility, global carbon change, and soil organic matter recirculation. Organic matter is part of soil that is produced by soil organisms and contains plant and animal remains in different stages of decompositation. This research was conducted in order to evaluate the effects of management practices on earthworms population, microbial respiration and biomass of soils of Esfahan fields an experiment was conducted during 2011-2012. 

In each of 23 county of Esfahan, 6 fields were selected and in order to fields classification, evaluation was conducted using questionnaires and that farmers filled. Within questionnaires, field classification was into three groups (low inputs, medium inputs and high inputs). In the laboratory, each soil sample from the studied farms was examined separately and the number of earthworms in each sample was counted and recorded. In order to evaluate the population and microbial activity, soil carbon and nitrogen were measured by microbial extraction method. Soil samples were extracted in the laboratory and the organic carbon of the extracts was measured using a TOC device and the microbial carbon was calculated.

Result indicated that soil of low inputs had the highest microbial respiration (30.5 mgCO2.kg-1 soil), biomass (380µg.kg-1 soil) and earthworms population (3 Per kg Soil). Soil of high inputs had the lowest microbial respiration, biomass and earthworms population (18.5 mg CO2 .kg-1 soil, 195µg.kg-1 soil and 0 per kg Soil respectively). 

According to other studies, in soils where there are plant residues or green manure and cover crops have been used, a high level of earthworm population, biological activity and soil fertility can be maintained. Earthworm populations are effected by structure and soil fertility. Microbial population in low inputs agroecosystems, was higher than medium and high inputs agroecosystems. Thus microbial respiration was higher in low inputs agroecosystems. Earthworms population in low inputs agroecosystems was also higher than medium and high inputs agroecosystems and the reason of high earthworms population was more residual plants in low inputs agroecosystems. Microbial biomass in low inputs agroecosystems higher than medium and high inputs agroecosystems. Reason of microbial biomass decrease in high inputs agroecosystems was application of conventional tillage. According to other studies, crop rotation and soil improvement has important roles in promoting population and soil microbial activity. The results of this study showed that the application of low inputs management methods leads to improved population and activity of soil microbial communities, so replacing chemical inputs with field inputs as a way to promote soil microbial communities. According to other researchers, less soil degradation in low input agroecosystems due to the use of no-tillage or minimum tillage methods leads to improved soil microbial population. The results of similar research indicates that the use of reduced plowing methods strengthens the population of earthworms. On the other hand, the use of pesticides and herbicides as well as the burning of plant debris on the soil surface reduces the population of earthworm. In soils were mulch is used, temperature fluctuations were reduced, which preserves earthworms in the soil. Acknowledgements:I would like to express my sincere appreciation to all the people who helped me during this research and provided me with the necessary facilities. I would also like to thank the professors and staff of the faculty of agriculture of Ferdowsi University of Mashhad for their cooperation with me.

Aloe vera is a permanent, evergreen species with special industrial and pharmaceutical applications. However, information about its nutrition management is scarce. Plants absorb nutrients through complex interactions in the rhizosphere between roots, symbiotic or non-symbiotic microorganisms and soil fauna. Inoculations of soil microorganisms (in the form of biofertilizers) to improve crop production and plant health were mainly undertaken for the group of bacteria known as PGPB (plant growth-promoting bacteria) or PGPR (plant growth-promoting rhizobacteria) and mycorrhizal fungi. To be effective, inoculated organisms must have soil conditions that are suitable for development, which can be improved by applying manure. Compared to the use of inorganic fertilizers, the application of organic manure in agriculture fields results in significant effects on microbial biomass, on the profile of existing species and, consequently, on the enzymes they circulate in the soil and its pool of organic matter. In this way, it interacts with the overall fertility of the environment. Different options of soil fertility management for increasing yield of aloe vera were studied in a field experiment.

A split plot experimentwas conducted based on randomized complete block design with three replications during 2012-2013 growing season in Agricultural Research Center of Bushehr province (29º16'0"N 51º31'0"E and 110 m above sea level). Seedlings were planted on May 4, 2012 with a distance of 0.7 m spacing on row with 1 m distance. The distance between Aloe vera rows was 1 m. The drip irrigation method was used for irrigation.  Main plot factor consisted of 0 and 20 ton.ha-1 sheep manure and five methods of soil fertility management were assigned to subplots including 1) chemical fertilizer (80 kg.ha-1 super phosphate+200 kg.ha-1 urea), 2) Mycorrhiza (using soil containing fungi from mosea), 3) biological fertilizer nitrogen (containing Azotobacter spp; Pseudomomas spp; and Azosprillium spp), 4) combination of Mycorrhiza and Nitrogen, and 5) no fertilizer (control). Monthly samplings were taken in 150, 180, 210, 240, 270 and 330 days after planting. Fresh and dry weight of leaves, leaf length, width and thickness and number of leaves per plant were measured. Harvestable leaves were considered as final yield.

The results indicated that interaction between manure and chemical or biological fertilizers was significant for all measured traits. Application of sheep manure was led to significantly higher growth and yield of aloe vera with better performance when manure was combined with chemical fertilizers. The highest number of leaves was obtained from integrated use of manure and chemical fertilizers with about 15 leaf per plant. While the lowest number of leaves was observed in control treatment. The interaction between treatments had a significant effect (p≤0.01) on leaf thickness. Plants treated with combination of chemical fertilizer and sheep manure had significant differences with other treatments, except with integrated use of biological fertilizers and manure. The highest fresh and dry weight of plant 3107.2 and 78.1 g plant-1, respectively and the highest final yield (36.04 tons.ha-1) was achieved with integrated use of manure and chemical fertilizers. The results also indicated that high aloe vera yields with great quality could be obtained with combined application of manure and biological fertilizers as an alternative for chemical fertilizers.

Producing medicinal plants under low input of chemical fertilizers is of great importance for human health, environment as well as production costs. Results of this experiment showed that application of manure with biofertilizers could be considered as a proper alternative to chemical fertilizers. Nutrition of aloe vera with this integrated management method will results to high yield and quality in addition to improving the physical, chemical and biological properties of soil.AcknowledgmentWe are grateful to Ebrahim Farrokhi and Kohzad Sartavi for their help with the field experiments, collecting field data and providing necessary advices to carry out this work.

Conventional tillage-based farming systems had negative effects on the quality of essential natural resources including soil, water, and plant biodiversity. In the recent decades, Conservation Agriculture (CA) farming systems based on the three interlinked principles, namely: no or minimum mechanical soil disturbance, crop residue retention and crop rotation introduced and adopted as an alternative to conventional agriculture. However, the influence of conservation agriculture practices on the population of soil-borne plant pathogens including plant parasitic nematodes is not well studied. This study was performed to determine the effect of different tillage methods and different levels of residue management on the population of plant parasitic nematodes in the wheat-barley-cotton-wheat rotation system during five consecutive cropping seasons (2012-2017) at the Gonabad Agricultural Research and Education Organization.

The experimental design was split-plot layout based on a randomized complete block design with three replications. Three tillage methods (such as conventional tillage, minimum tillage, and no-tillage) were assigned to main plots and three levels of residue retention (no residue retention, 30% of residue retention, and 60% of residue retention) were assigned to sub plots. The planting area of each subplot was 450 m2 (30 m length and 15 m width) and the total are of each main plot was 4050 m2 (9×450 m). To compare the population density of plant pathogenic nematodes in different crops, a combined soil sample from each experimental plot was collected. The nematodes were extracted from soil samples using sieving and centrifugal-flotation technique and were identified to genus or species level using relevant systematic references. The data were analyzed using MSTAT-C statistical software package. The Duncan multiple range tests were applied to separate the differences between means.

Plant pathogenic nematodes including root lesion nematode (Pratylenchus thornei), pin nematode (Paratylenchus spp.), spiral nematode (Helicotylenchus spp.), Geocenamus spp., stem and bulb nematode (Ditylenchus spp.), Boleodorus spp., Tylenchus spp. and Filenchus spp. were identified in different treatments. Based on the results of analysis of variance, the effect of tillage methods, residue retention and the interaction between tillage × residue retention was not statistically significant on the population of most plant parasitic nematodes but the interaction between tillage × residue retention was significant on the total number of plant parasitic nematodes and the population of Tylenchus spp. and Geocenamus spp. In average the highest density of plant pathogenic nematodes was related to the no-tillage system with 30% of residue retention and the lowest density was related to the minimum tillage system with 30% of residue retention. The results of this study indicated that different tillage systems and different levels of residue retention under the wheat-barley-cotton-wheat rotation system do not affect dramatically the population density of important species of plant pathogenic nematodes including the root lesion nematode (Pratylenchus thornei). Some other studies reported that reducing tillage intensity was associated with reducing population densities of plant pathogenic nematodes, which was contrary to the results of this study.

The results of this study indicated that conservation agriculture under the wheat-barley-cotton-wheat rotation system in temperate climatic zone of Khorasan Razavi (Gonabad) does not significantly affect the population of plant pathogenic nematodes and increases the risk of crop damage by this group of plan pathogens.AcknowledgementsThis study has been financially supported by the Agricultural Research, Education and Extension Organization (AREEO) and the Seed and Plant Improvement Institute (SPII) (project number 17-43-03-9154-91002).The authors would like to thank AREEO and SPII for their financial and administrative supports.The excellent technical and laboratory assistance of A. Rastegar Paymani and A. Ahmadian Yazdi from the department of plant protection is acknowledged.

Application of organic fertilizer is a major approach to managing soil fertility and plant nutrition which can alleviate chemical contaminations, preserve soil biodiversity and the quantitative and qualitative yield of crops expected to be increased in sustainable agricultural systems. Consequently, demand for organic products has increased due to health and sustainable environment consideration, particularly for medicinal products. Intercropping is the cropping system of growing two or more crops simultaneously in the same field and is a sustainable method for increasing crop production compared with sole crop. The main objective of the study was to determine the effect of vermicompost and intercropping patterns on seed yield and macro and micronutrients uptake of fennel (Foeniculum vulgare Mill.) and faba bean (Vicia faba L.). 

In order to compare the different intercropping patterns of fennel and faba bean under the application of vermicompost fertilizer, a field experiment was conducted as factorial based on a randomized complete block design with three replications at the Research Farm of the Faculty of Agriculture, University of Urmia, Iran, during the growing season of 2018. The first factor consisted of six cropping patterns including sole cropping of fennel and faba bean, one row of fennel+ one row of faba bean, two rows of fennel+ two rows of faba bean, three rows of faba bean+ two rows of fennel, four rows of faba bean+ two rows of fennel) and the second factor included the non-application and application of vermicompost (10 t ha-1).Plant samples were digested according to Jones and Case (1990) procedure. Seeds of faba bean and fennel were analyzed for macro- and micronutrients. In addition, Area Time Equivalent Ratio (ATER) was calculated to determine the advantages of intercropping. The analysis of variance was performed using SAS 9.4 software. Means were compared using Duncan's test at the 5% probability level. 

The results showed that the effect of cropping pattern on all measured traits was significant. The results revealed that the seed yield of fennel and faba bean increased following the application of vermicompost fertilizer. Moreover, concerning the effect of cropping patterns, the highest seed yield of fennel (2568.33 kg.ha-1) and faba bean (2851.67 kg.ha-1) were obtained in the sole cropping of these two plants. The higher production in fennel and faba bean sole cropping may be due to the less disturbance in the habitat in homogeneous environment under sole cropping systems. The highest amounts of N, P, K, Ca, Mg, Fe, Zn, Cu, and Mn were obtained in the treatments of intercropping and vermicompost application. The higher concentrations of nutrients in intercropping pattern could be explained by increasing root exudation and also better use of available resources that increased the accessibility of nutrients for component plants. The highest ATER (1.14) was obtained in the three rows of faba bean+ two rows of fennel intercropping system fertilized with vermicompost. According to the ATER, it seems that three rows of faba bean+ two rows of fennel under the application of vermicompost was suitable for increasing productivity and making the best usage of environmental resources in order to achieve an optimal production, decrease costs and dependence on external inputs, and reducing pollution and environmental pressures on sustainable agricultural systems. 

In general, the results of this experiment showed that the faba bean and fennel yield were influenced by different intercropping patterns and vermicompost. The highest seed yield for both plants (faba bean and fennel) were obtained in sole cropping. In the present study, the application of vermicompost could improve the yield of faba bean and fennel and nutrient uptake. It seems that the use of vermicompost in intercropping is one of the suitable strategies for achieving optimal yield with minimum inputs, which in the long term can reduce the need of chemical inputs for cropping systems.

The problem of energy efficiency is one of the key pillars of economics, especially agricultural sector. In term of energy efficiency, a similar estimation for human actions and their consequents can be applied to the landscape system, which first introduced by Hall et al. (1986), and now referred to Energy Return on Investment (EROI). Many energy analyzes have been done, take into account a social system boundary and an input and output approach. This approach will inevitably hide the system's internal performance inside a black box. Recently, Tello et al. (2016) have proposed a novel approach for analyzing energy at the agricultural landscape scale with the aim of evaluating energy sustainability under multiple EROIs that views the landscape as a set of energy cycles between nature and society.The proposes of this study have been to consideration the theory and methodology of multiple EROIs, to investigate the efficiency of energy flow in Qazvin agricultural landscape and, to examine the relationship between energy efficiency and landscape heterogeneity in order to describe the interaction of landscape structure and energy efficiency.

The database of this case study was prepared from 46 counties of Agricultural Organization of Iran and land use map. Agricultural database was created based on agriculture, livestock, and pasture subsystems. Agricultural yield for each crop, number of agricultural, and horticultural labors, number and type of agricultural machinery, amount of fertilizers, herbicides and fungicides, used fossil fuels, electricity, and agricultural waste belonged to the agricultural sub-sector. Census of livestock, livestock and poultry production, livestock and poultry feed, livestock and poultry production, workers and machinery, fossil fuel and electricity needed and livestock waste were collected for the livestock sector. Pasture production used for livestock grazing, amount of livestock manure going back to rangelands were belong to pasture sector.All energy flows were converted to gross caloric value following research by Guzmán et al. (2014). In this method, the calculation of multiple EROIs has replaced the conventional methods of energy efficiency calculation. Landscape heterogeneity calculated using landscape metrics. Correlation coefficient was performed using SPSS between EROIs and heterogeneity.

The highest value of FEROI was found in Bashariyate Sharghi with 0.25 and the lowest was in Kharghane Gharbi with 0.018. EFEROI, which is the most similar to the conventional method of energy efficiency, had the highest rate with 0.666 in Bashariate Gharbi and the lowest rate with 0.020 in Kharqan Gharbi. IFEROI was 0.95 in Narjah and the lowest was in Shahidabad with 0.168. Lower IFEROI indicates a higher return biomass in the production system, which seeks to maintain reproduction in the system by closing the biophysical cycles. The highest NPPEROI were reported by Bashariate Gharbi at 1.122 and lowest by Kharqan Gharbi at 0.173.In this study the relationship between the EROIs index and the heterogeneity of the landscape structure was shown. The results have showed the inverse correlation between heterogeneity and energy efficiency, indicating the heterogeneous impact of landscape structure on these indicators. It can be deduced that the heterogeneity created by human in Qazvin province has reduced energy efficiency. To explain this inverse correlation between energy efficiency and the heterogeneity of the landscape, it should be noted that one of the factors affecting efficiency is that may final production come from land uses that needed more input energy and produce less output. By examining the relationship between these indices with land use and land cover of each county, it was found that these indices had their lowest level in dry farming. It means that in Qazvin province, energy efficiency in dry farming is low, and relay on external inputs, which was mainly fossil fuel.

This study has explained how the calculation of several energy efficiency coefficients provides more complete information than conventional methods for decision making. The results of this study can be applied in land use planning to integrate energy considerations in planning and comprehensive agricultural development plan.

Intercropping is one of the main strategies to obtain more stability in agro-ecosystems. The possibility of yield improvement in intercropping systems depends on various factors such as plant combination, cultivar type, plant density, planting pattern, and contribution of each species. Introducing new crops or forgotten plants to agro-ecosystems are other methods for sustainable crop production. Quinoa as a potential new crop to be introduced to Iran’s farming systems, is well-adapted to different environmental conditions. This plant has high nutritional values and produces acceptable yield to areas affected by environmental stresses like drought and salinity stresses. Millet, as a forgotten crop in Iran’s agro-ecosystems, is a drought-tolerant grain, with appropriate growth and yield in arid and semi-arid regions. This C4 plant has vertical leaf distribution, rapid and short growth period which make it tolerant to adverse environmental conditions compared to other cereals. The aim of this study was to evaluate the possibility of quinoa and millet intercropping under arid and semi-arid climate of Birjand, Iran.

A factorial experiment based on a randomized complete block design (RCBD) with three replications was conducted in research field of University of Birjand, Iran, in 2018. The experimental factors were planting density at three levels (20, 40, and 60 plants m-2 for both quinoa and millet) and planting ratio at five levels (pure stand of millet (100 %), three rows of millet and one row of quinoa (75%-25%), the equal ratio of millet and quinoa (50%-50%), one row of millet and three rows of quinoa (25%-75%) and monoculture of quinoa (100%). Experimental plots area was 24 m2 (6 m×4 m), with eight planting rows per each. The distances between planting rows in all treatments were 50 cm, while the distances along the single rows were 10, 5, and 3.3 cm for 20, 40, and 60 planting densities, respectively. The grain and biological yields of both plants were determined, finally, various indices including land equivalent ratio (LER), relative yield (RY), competitive ratio index and aggressively index were calculated. Data analyses were done using SAS 9.2 and means were compared by FLSD test at 5% probability level.

The simple and interaction effects of planting density and ratio had a significant effect on grain and biological yield of quinoa and grain yield of millet (P < 0.01). In addition, planting ratio had a significant effect on the biological yield of millet (P < 0.01). Based on data obtained from monoculture system, the optimum plant density to obtain the highest grain yield of millet (4100 kg.ha-1) and quinoa (2340 kg.ha-1), were 60 and 40 plants per m2, respectively. Considering the different ratios of planting, the participation and positive effect of both millet and quinoa plants in an increasing the land equality ratio has been equal. By increasing the density, the advantage of mixed cultivation has been reduced. The best intercropping systems in terms of LER (1.32) were the density of 40 plants per m2 (for both crops), and planting ratio of 25% millet and 75% quinoa, which had 26.98% actual grain yield incensement. In addition, the results of interaction effect showed that this treatment increased the biological yield of quinoa (6935 kg ha-1) by 9.26%, based on anticipated yield. In this density, it seems that the result of optimal use of existing inputs and reduction of internal and external competition in order to achieve maximum yield has been achieved. The results of the relative yield indicated that the millet is better utilized from environmental resources and conditions due to its predominance and competitiveness. In general, the results of evaluating mixed culture indicators based on the principles of assistance and competition were complementary and confirming each other.

The results showed that millet and quinoa had significant effects on each other when intercropped at different planting densities and ratios due to difference of morphological and physiological characteristics. So according to the goals of intercropping recommended the intercropping systems of millet and quinoa for Birjand region.

Cereal-legume intercropping is a common approach in agricultural systems especially in developing countries. Bitter vetch is a forage legume that belongs to Fabaceae family. This plant can play a role in improving soil fertility by nitrogen fixation, which leads to the benefit of intercropping with forage grasses such as barley. Planting date and density are the determinants of optimal crop yield in intercropping systems. As the planting date changes, meteorological parameters (temperature, sunlight and…) also change, and influencing plant growth and production. The purpose of determining the optimal planting date is to synchronize the growth stages of the plant. On the other hand, plant density varies with factors such as area differences, planting date, climatic conditions and soil type. Vicia ervilia L is a plant of the legume family, which is partly drought tolerant and compatible with most soils. In this research, the forage quality of bitter vetch was evaluated in additive intercropping pattern with barley as well as in different planting dates.

The experiment was carried out as a factorial arrangement based on randomized complete block design with 3 replications. The studied factors were included planting dates at three levels (simultaneous planting of bitter vetch and spring barley on March 25, planting of bitter vetch 10 and 20 days after planting of spring barley on April 5 and 16, respectively) and planting densities at four levels (12.5, 25, 50 and 75%) in additive intercropping with spring barley. Bitter vetch and barley pure stands were considered as control treatments. Bitter vetch was harvested for forage at flowering stage. Forage quality indices including organic matter, acid detergent fiber (ADF), neutral detergent fiber (NDF) and mineral nutrients were measured in bitter vetch. Analysis of variance was performed using SAS software and means were compared by Duncan's method at the 1% probability level.

The results showed that the highest amount of organic matter, neutral and acid detergent fibers in bitter vetch forage were obtained in simultaneous planting of bitter vetch and spring barley. The lowest values ​​were obtained in sowing bitter vetch 20 days after barley planting, while the highest amount of mineral elements including nitrogen, potassium, sodium and calcium was obtained from sowing bitter vetch simultaneous with barley planting. The delay in bitter vetch sowing makes the plant less likely to grow and increases intensity of its competition with barley for food resources, which reduces the content of forage nutrients contents. The highest phosphorus content was observed at the third planting date (20 days after sowing spring barley) with an average of 52.40 ml.L-1 and was significantly different from other levels of planting date. It seems that the delay in bitter vetch sowing date and the decrease in vegetative growth and its competition with barley for mineral resources of soil did not have a decreasing effect on the phosphorus content and apparently the phosphorus content also increased in the delayed sowing conditions. Increasing bitter vetch density increased nitrogen, potassium and sodium levels of bitter vetch forage but decreased magnesium, phosphorus and calcium contents. Dry matter digestibility was not affected by sowing date, plant density and their interaction. The highest acid detergent fiber (ADF), neutral detergent fiber (NDF) was belonged to 12.5% ​​and the lowest were for 75% bitter vetch density. The planting date of April 6 was preferable to other planting dates in terms of mineral elements and the bitter vetch density of 75% was better due to the reduction of NDF and ADF indices. Results of previous experiments showed that in cereal crops and legume intercropping, the contents of acid detergent fiber (ADF), neutral detergent fiber (NDF) in forage were decreased.

In general, the results of this study indicate that the contents of mineral nutrients including calcium, sodium magnesium and phosphorus of forage were higher in intercropping treatments than pure cultivation and the amounts of organic matter and digestible dry matter of bitter vetch forage in simultaneous intercropping with barley were equal to those of pure cultivation. Decreased acid detergent fiber and neutral detergent fiber in forage and production of forage with higher contents of minerals including phosphorus, magnesium and calcium are benefits of intercropped bitter vetch and spring barley compared with soleculture.

Metals and metalloids with a density greater than 5 g.cm-3, are recognized as heavy metals. These elements are almost thermally stable and non-biodegradable, resulting in high persistence and accumulation of toxic levels in the environment. Some heavy metals like chromium could be distributed as a result of anthropogenic activities like transportation, mining and industries, which may be toxic to human and plants even at low concentrations. For instance, Chromium may be accumulated in human tissues, resulting in some killing diseases. Modelling and monitoring of heavy metals in soil, water bodies and vegetation are vital techniques to developing remediation strategies. Hormozgan province has more than 14000 ha under tomato cultivation with a total yield production about 630 tons. A relatively large part of these farms are located in Western Hormozgan, adjacent to the busy roads and industrial sites, which makes them important to be evaluated for heavy metals pollution in both soil and plant. The present study was undertaken to investigate some soil physical and chemical properties as well as chromium content in soil and tomato plant tissues in farms of western Hormozgan province in Iran.

The study was conducted during 2015-2017 in three main regions of tomato cultivation in western Hormozgan. Some industries including an oil refinery, a gas company and medical hospitals were located relatively near the studied farms. However, traffic activities on the busy roads parallel to the studied farms could be the main reason for soil heavy metals pollution. We studied the soil chromium concentration, as well as the uptake and distribution of chromium in different organs of tomato plants in nine heavy metal polluted farms in western Hormozgan. In addition, two important contamination indices of bio concentration factor (BCF) and translocation factor (TF), were calculated for chromium in all studied farms. All data were subjected to analysis of variance and means comparison was performed by Duncan̕s Multiple Range Test.

The results showed that chromium concentration was higher than the critical level (2 mg.kg-1) in almost all examined soils. All the studied farms were adjacent to the factories, hospitals and busy roads. Therefore, the location could be considered as the main reason for soil, water and plant pollution. Plant accumulation of Chromium was also as follows: fruit peel-1 dry weight) that could cause serious health problems in human body. More than one third of fruit chromium content was accumulated in the peel, showing a practical suggestion to reduce chromium entrance into the human body through separating the peel from the pulp before consumption of tomato fruits. The results also showed that increasing soil salinity reduced plant potential for soil chromium extraction, despite of the significant enhancement of soil available chromium concentration resulting from increasing salinity level in soil saturation extract. Furthermore, bio concentration factor declined as a result of soil salinity increasing, because the rate and intensity of chromium uptake by the plant was lower than those of soil chromium content increase in saline conditions.  

The results showed that tomato has a considerable potential for chromium uptake in polluted soils. Neighboring industries and roads were recognized to be the main reasons for high chromium contents in the studied soils in fields of Hormozgan province. Thus, it is highly recommended to establish tomato fields far from crowded roads, factories and industrial sites.AcknowledgmentThe present manuscript was prepared as part of a research collaboration between "Hormozgan Agricultural and Natural Resources Research and Education Center" and "Hormozgan University of Medical Sciences". We are so grateful for the supports.

The medicinal plant Dragon's head (Lallemantia iberica, Lamiaceae family), is more commonly known as “Gara Zayrah” in most parts of Iran, particularly in Azarbaijan region. It is one of the most important spring herbaceous plants in rainy and dryland farming areas cultivated in most parts of Azerbaijan. The ever-expanding soil salinity under the influence of human activities restricts crop production worldwide, especially in arid and semiarid regions. One of the strategies to enhance the crop yield is increasing in off-farm inputs like application of fertilizers. Managing or adding fertilizer can severely affect crop production in saline conditions. Therefore, nutrient addition can increase or decrease plant resistance to salinity or it may not be affected by salinity at all. Accordingly, due to the importance of Dragon's head as a climate-adapted medicinal plant in Iran, this study aimed to evaluate the effect of nitrogen fertilizer sources (urea and Azotobacter) on the morphological characteristics of Lallemantia under salinity conditions.

An experiment was conducted as factorial layout based on randomized complete block design with three replications in 2018 at Urmia University (latitude 44° 58' East, latitude 37 ° 39' North and altitude 1363 m above sea level). Treatments consisted of four levels of nitrogen fertilizer (urea fertilizer, 50 kg/ha), Azotobacter as a foliar spraying and Azotobacter as a seeds inoculant (population of 109 per g) and no-fertilizer as control), and two soil salinity (saline was 6.70 and non-saline was 0.91 dS.m-1). The seed yield, biological yield, leaf relative water content, leaf area, leaf perimeter, leaf area index, sodium, potassium and phosphorus content in root and shoot, glycine betaine, osmolytes (osmotic regulators), leaf chlorophyll and carotenoids of Dragon's head were measured. The analysis of variance (ANOVA) was performed using GLM procedure (SAS 9.1.3, SAS Institute Inc., Cary, NC, USA), with the means compared by LSD at P≤0.05.

The results showed that in non-saline conditions, the biological yield (regardless of root, as well as root included) treated by Azotobacter seed inoculant were decreased compared with control, while the biological yield of untreated control plants were identical with the application of other nitrogen treatments. However, biological yield increased by Azotobacter seed inoculant in saline soil. In contrast to the decrease in stem length in saline soils, especially with the Azotobacter foliar application, the flower weight gain was significantly higher with urea fertilizer even under saline conditions. The highest crop growth rate (regardless of root, as well as root included) was related to plants grown in saline soils without fertilizer application. In other words, except for seed treatment, Azotobacter had no significant effect on crop growth rate under salinity. Moreover, the greatest amount of root potassium was obtained from plants in non-saline conditions with urea fertilizer. Despite the decrease in aerial phosphorus under salinity stress, root phosphorus was not affected by salinity, whereas urea increased shoot and root phosphorus. The plants had the highest concentration of total chlorophyll and carotenoids under salinity and foliar application of Azotobacter. The highest reduction of carotenoid was observed in saline soils in control plants, urea and Azotobacter seed treatments, respectively. Despite increasing proline concentration in plants grown in saline soil, urea and seed inoculation lead to decreasing the leaf proline. Other osmotic regulators, glycinebeta and water-soluble carbohydrates were not affected by soil salinity and nitrogen fertilizer sources. Shoot and root sodium were increased in saline soils, and applying urea fertilizer caused more increases. Root potassium was not changed in saline soils, but potassium content of aerial parts was decreased. This resulted in a decrease in the potassium to sodium ratio of both aerial parts and the root.

In general, despite some minor changes, salinity caused decreasing the level of morphological and physiological responses related to the yield of Dragon's head plant. However, applying nitrogen fertilizers reduced salinity damages by seed inoculation of Azotobacter and urea, respectively. Azotobacter foliar application showed no advantage over saline and non-saline conditions over control treatment (without receiving fertilizer).

Natural scientists and agricultural experts are aimed to provide the right methods of ecosystem design in order to promoting the health of natural systems, optimizing input consumption, enhancing production per unit input consumption, improving economic efficiency and increasing ecological sustainability. To achieve these goals, it is necessary to assess the sustainability of the agroecosystem to identify challenges and strengths. Quantification of sustainability leads to an increase in awareness of the state of the system, which is of particular importance in making the right decisions and managing them. Emergy is a thermodynamic tool for assessing the sustainability of biological and agricultural systems. By evaluating and comparing the sustainability of production systems in this way, human activity in the ecosystem is translated into the language of thermodynamics. Over the past three decades, emergy as a powerful tool has been prove to examine the overall performance and sustainability of the different production systems. The use of emergy analysis approach in assessing the sustainability of crop systems, leads to the application of proper management to increase the sustainability of production in these systems. In this study, six production systems of wheat, onion, garlic, fennel, cumin and black seed were evaluated in the city of Helmand, Iran, using ecological and economic indicators in terms of ecological sustainability.

This study was conducted in the production systems of wheat, onion, garlic, cumin, fennel, and black seed in Hirmand County in 2019 and 2020. For this purpose, 117 farms were selected for wheat, 47 farms for onions, 32 farms for garlic, 17 farms for cumin, 12 farms for fennel and 8 farms for black seed. Information on inputs and outputs of crop systems were obtained using the following two methods first, verbal estimates using a questionnaire, and second, field measurements and researchers' observations. In this study, free renewable and non-renewable environmental inputs and non-free inputs for two systems were determined in terms of the same unit of solar emjoule (sej). To analyze production systems and calculate the indices, inputs were categorized into four types; free renewable environmental inputs (R), free non-renewable environmental inputs (N), free renewable inputs (FR) and non-free non-renewable inputs (FN). The emergy-based indices calculated in this study were Transformity (Tr), Renewable emergy percentage (%R), Emergy Yield Ratio (EYR), Emergy Investment Ratio (EIR), Emergy Exchange Ratio (EER), Environmental Loading Ratio (ELR), Emergy Sustainability Index (ESI), and Emergy Index of Product Safety (EIPS).

Total emergy supporting for the production systems of wheat, onion, garlic, fennel, cumin and black seed in Hirmand County were 3.25E+16, 3.37E+16, 4.36E+16, 2.29E+16, 1.84E+16, and 1.82E+16 sej ha-1, respectively. Free environmental flows represented 74.27, 67.85, 52.21, 56.16, 56.56 and 52.49% of the total input energy of the production systems of wheat, onion, garlic, fennel, cumin and black seed, respectively. The large share of free internal inputs indicated that most of the studied farms are non-industrial systems that are traditionally managed and low-input. The values ​​calculated for the sustainability indices (ESI and ESI*) showed that the ecological sustainability of the fennel production system is higher than the other systems. The main reason for the greater sustainability of this system was the high share of energy input related to free environmental inputs and economic renewable resources. In addition, high emergy exchange ratio (EER), environmental sustainability resulting from the impact on the market, less emergy expended in the production of each unit of production and higher productivity of all production factors indicated a greater comparative advantage of the fennel production system.

 Overall, assessments based on the calculation of 14 emergy and economic indicators showed that special attention to practical solutions for the overall management of production ecosystems, in particular the protection of the soil organic matter and preventing soil erosion can increase the ecological sustainability in the main agricultural systems of Hirmand County.

Intercropping of medicinal plants with forages is an approach to improve livestock health. In fact, intercropping is more efficient than monocropping systems because of superior yield due to better absorption of resources. Forage with a high nutritive value can be produced using intercropping systems along with manure fertilizer, and more recovery nutrients can be observed in the multiple cropping systems than single cropping systems. Sainfoin (Onobrychis viciifolia Scop.) is an important forage legume, which has been cultivated for hundreds of years in many parts of the world, especially Asia, Europe, and North America. There is a renewed interest in sainfoin because of its use in animal diets and key nutritional properties such as high nutritive value and high forage palatability. The medicinal herbs are considered as natural products, with growth-promoting and antioxidant effects, and consequently, consumers may be using them for livestock feeds. Fennel (Foeniculum vulgare Mill.) is an annual medicinal and aromatic plant belonging to the Apiaceae (Umbelliferaceae) family and is native to the Mediterranean area. As the quantity and quality of forage production and the importance of medicinal plants in nutrition, the goal of the study was to investigate the methods of intercropping systems on forage quality of sainfoin and fennel under cow manure and urea fertilizer treatments.

In order to investigate the effects of fertilizer sources and intercropping ratio, a split-plot experiment was conducted as a randomized complete block design with three replications at Shahrekord University research farm during 2015 and 2016. Five fertilizer sources (chemical fertilizer, chemical + manure fertilizer (1: 1), (2:1), (1:2) and manure fertilizer) and sole cropping of fennel (F), and sole cropping of sainfoin (S), and three intercropping ratio (F: S 3:1, 1:1 and 1: 3) were also considered. The N fertilizer treatments and intercropping systems were arranged in main and sub-plots, respectively.Forage quality parameters include Crude Protein (CP), Crude Fiber (CF), Dry Matter Digestible (DMD), Water-Soluble Carbohydrate (WSC), Neutral Detergent Fiber (NDF), Acid Detergent Fiber (ADF), Ash (ASH), and Metabolism Energy (ME) were measured using standard procedures.

The results showed that forage quality traits of sainfoin and fennel were significantly affected by N fertilizer and mixed crop patterns. The highest crude protein was related to sole cropping of fennel and higher ratios of chemical fertilizer in the first year, and intercropping and higher ratios of manure in the second year. The highest dry matter digestibility has obtained for the monocropping of sainfoin with integrated fertilizer. Crude fiber and acid detergent fiber decreased in higher ratios of sainfoin. Metabolism energy was higher under chemical fertilizer in the first year and under manure in the second year, as well as the ash under manure, and both were higher in monocropping of fennel. Previous studies conducted a berseem clover and basil intercropping system and reported that all of the forage quality traits of berseem clover, including DMD, CP, WSC, NDF, ADF, and ASH were improved in the additive intercropping system as a legume–basil mixture. They demonstrated that interactions between intercropped plants played an important role in the quality improvement of the forage due to better light interception.

In general, our findings showed that N fertilizer sources and intercropping systems affected the forage quality of the fennel and sainfoin. We suggest 50 % fennel + 50 % sainfoin with 50 % manure + 50 % urea fertilizer.