نشریه بوم شناسی کشاورزی
سال دوازدهم شماره 1 (بهار 1399)

Canola (Brassica napus) is a major oilseed crop in the world, and its oil is used not only for salad and frying but also in the processing of margarines, shortenings, and other food products. Canola (Brassica napus L.) is often called a flexible or plastic crop because individual plants can adjust the number and size of branches and pods they produce in response to available moisture, light and nutrients. Therefore, canola naturally compensates for variations in plant population over relatively wide ranges with very little effect on final yield. At plant densities of 70-100 plants per square meter (approximately 7-10 plants per square foot), canola plants normally produce 3-5 secondary branches, in addition to the main stem. At low densities of 20-30 plants per m2, this plant can produce up to four times the number of branches that stands of 70-100 plants per m2 produce. Extension of canola cultivation varieties need effective instruments to follow up characters associated with yield and yield components. Therefore, determination of the response of canola cultivars to plant density is principally important and in general plant density is the most important factor which limit yield production on farmlands.

In order to determine the best planting density for rapeseed cultivars, this experiment was conducted at the agricultural research field of Ferdowsi University of Mashhad, in 2011. A factorial experiment based on RCBD with three replications was used. Factors were cultivars (Hayola401 and Modena) and planting density (40, 70, 100, 130, 160 and 190 plants.m-2). A composite sample of soil from the surface of the ground down to the depth of 30 cm was taken and sent to a laboratory for determining the physical and chemical features of the soil. Results of tests carried out on these samples showed that the available phosphorous, and the available potassium contents of the soil were 31.5 mg.kg-1 and 267 mg.kg-1, respectively. The soil pH was 7.3 with texture containing 40% clay, 41% silt, and 19% sand. Distance between plots was 0.5 meter and between replications 1 meter used as passage way. At crop maturity, five plants were randomly selected from each plot and the seed yield and yield components (including number of seeds per pod, number of pods per plant and the 1000-seed weight) were measured. Analysis of the variance was performed using the SAS statistical software, and comparison of the means was performed on the basis of duncan’s multiple range test at five percent probability level.

Results showed that there were significantly differences between plant density on rapeseed cultivars. Canola crops need 30-40 plants per m2 (approximately 3-4 plants per square foot) to maintain yield potential. Plant populations lower than this is more likely to have yield loss. The average grain yield in Modena cultivar was 13.5% higher than in Hayola401 cultivar. Number of pods per plant in Modena was significantly higher than in the Hayola401.When plant density decreased from 40 to 190 plants.m-2, plant height of rapeseed increased. The greatest number of seeds per pod, biological yield, harvest index and oil percentage were observed in 70 plants.m-2.

Rapeseed cultivars responded strongly to changes in plant density. The average grain yield in Modena cultivar was higher than in Hayola401 cultivar. The maximum seed yield was observed in 70 plants.m-2.
Acknowledgement
This research was funded by Vice Chancellor for Research of Ferdowsi University of Mashhad, which is hereby acknowledged.

Avoidance of repeated soil tillage in conjunction with maintaining crop residues and plant nutrition management may help to conserve and improve the soil and plant conditions. Primary goals of conservational systems consist of eliminating some cultivation practices and increasing surface crop residues in the planting system. In such residue conserving systems, nitrogen fertilizers are considered as important elements in crop production and influence the pattern of soil organic carbon storage as well as crop growth and yield. Currently, cotton is mainly cultivating in many farms of the country, and in particular in the Southern Khorasan province, after removal of the residues of the previous crop, and few studies have been conducted on the importance of plant residues in this plant in Iran. Therefore, this research was carried out with the aim of investigating the interaction of barley plant residues and different levels of nitrogen on yield and yield components of cotton in two different tillage systems (conventional tillage with moldboard plowing and reduced tillage with disk).

To study the effect of application of different residue amounts and nitrogen fertilizer under two different cultivation systems on dry matter accumulation, yield and yield components of cotton, an experiment was conducted as split-plot factorial design with three replications at the Faculty of Agriculture, University of Birjand, Birjand, Iran. The main plot consisted of two cultivation levels including conventional tillage (mould board plowing) and reduced tillage (disking). The sub-plot included two nitrogen levels (50 and 150 kg.ha-1) and five levels of barley residues (0, 77, 154, 231 and 301 g.m-2) which were factorial arranged in sub plots. Cotton, Khordad cultivar, was planted on 20th June 2013. Plant dry weight was measured at three stages over the growing season and cotton bolls were collected at two stages and the lint, seed cotton and cottonseed yields was recorded.

Results showed that the cotton emergence in moldboard plowing (46.8%) was significantly higher than disk (38.1%), and seedling emergence in both tillage systems decreased with increasing amount of residues on the soil surface. The highest percentage of emergence was related to zero residues in moldboard plowing and the lowest emergence was observed in low tillage (disc) with residues of 308 g.m-2. The residue application also reduced the plant dry weight early in the growing period. Although application of low amounts of residues reduced plant dry weight and cotton seed and lint yields compared to non-residue application at the end of the growing season, increased levels of residues, especially where high rates of nitrogen application and moldboard plow were practiced, remarkably increased these traits, so that the greatest lint yield (1.04 ton.ha-1) was observed with 308 g.ha-1 of residue in conjunction with application of 150 kg.ha-1 nitrogen and practicing moldboard plowing. Moldboard plow system caused a greater dry matter accumulation and crop yield and it seems that initiation of crop residue conservation and reduced tillage requires more time.
 
 

The research clearly demonstrated the beneficial effects of not removing plant residues and mixing them with soil even for a single crop season, which, in turn, emphasizes the avoidance of incorrect burning of the residues of the previous crop. According to this study findings, where 100% of previous crop residues are added to the soil, the application of nitrogen should be increased proportionally. Otherwise, a significant reduction in crop yield and yield components would be observed especially at high rates of crop residues. Moreover, it appears that reduced cultivation systems might not influence crop yield and even reduce it in short term and requires long term research studies to determine the efficacy of conservational cultivation systems.

Rice is a global important food and in Asia alone is the source of food for 3.5 billion people. Such demand for rice imposes a plan to find new technology and approaches to replace old production methods. About 75% of global rice production is practiced on low lands. At field scale, rice compared to other plants receive two or three times more water and based on some calculations, about 34-43 percentage of global irrigation water or 24-30 percentage of drinking water consumed by rice plant. In this situation, the most important challenge with regard to rice production, water storage, increased water productivity and rice production is less than water. Recently, rice production systems such as rice alternate irrigation, where less water can be produced, has been considered as rice increasing demand for water in industry and cities have imposed the reduction of water consumption for agriculture. Rice is one of the most sensitive plants against water scarcity as a floodplain plant and has the most need for water in the cereals. Rice has the highest crop area than other irrigated plants.

This experiment was conducted as split-plot, using irrigation as main-plot at five levels (full irrigation, irrigation at ever 5, 8, 10, and 15 days), and planting distance as sub-plot at four levels (20x20, 25x25, 30x15, and 30x20 cm) within format of random complete block design with three replications. The study was performed in two years (2016-17, 2017-18) in national rice research center. Soil samples were taken to determine the soil tissue, soil water holding capacity, and some chemical characters including EC, PH, and amount of Ca, Na, and Mg. Within firs 15 days after transplanting, the rotation irrigation was not employed so the plant be able to establish in the field. The plowing was performed in two times. The first plow in the late autumn and early winter and the second plow were perpendicular to the first plowing in the spring. Fertilization was done based on long term local practice. Transplanting was done in may, 15 and at this time transplants were 20-25 cm height carrying 4-5 leaves. All traits including stem and leaf dry matter, leaf area index (LAI), crop growth rate (CGR), net assimilation rate (NAR), leaf area ration (LAR), relative growth rate (RGR) and specific leaf area (SLA) were measured and calculated. SAS and SPSS software’s were used for analysis of variance. Excel software was used for drawing slices.

ANOVA results showed that interaction of irrigation and planting distance were significantly (P <= 0.01) affected leaf and stem dry matter, LDW, TDW and CGR Individual effects of each treatment significantly affected the LAI and NAR but did not affect LAR, LWR, RGR, and SLA. As light absorption i a limiting factor in crops production, then where is no other environmental stress, increasing light absorb will increase crop production. In contrast to other crops light capture competitions a major issue for rice. Increasing panting density, vegetative growth and LAI would be lower and as planting density decreases, due to availability more spaces, both vegetative growth ad LAI increased.

 In general, this study results showed that rotation irrigation significantly affected the rice growth indexes, and reduction levels of study traits depends on irrigation timing at growth stage. Planting distances showed that planting at 20x20 cm, provided the most optimum conditions for rice plants under different stress, the worst conditions resulted in 25x25 cm planting distance. At lower planting density, due to lower competition between plants till flowering time but after this stage, competition for photosynthetic materials increased among the seeds which can result in small dead seeds.

In the foreseeable future, plants are still the most important source of human food supply, and given the rapid rise in demand for food in developing countries, the demand for food will increase sharply over the next 20 years. Compression is the most important factor in increasing agricultural production. One of the useful indicators in determining the compression rate is the use of agronomic index. In Nepal, an applied definition has been used to compress agriculture, which includes increasing the number of crops per unit area in a crop season, along with the trend of chemical changes to improve plant performance. One of the important indicators used by many researchers is made by Boserup (1966). In this definition, agricultural compression  means increasing the cultivation of crops in a given period in an agricultural system., The idea of increasing the frequency of planting important crops originated in agriculture prior to industrialization and was the only way to increase crop production in one year. This concept later became more comprehensive by other researchers by adding the differences in the length of sowing and planting of crops. In a number of studies, the frequency of products indicating the amount of land use has been used as a compression index.

In order to study the trend of changes in crop density, agronomy and stability in agricultural production, statistical data of 15 agricultural variables including crop area and rainfall in different provinces of the country for the period of 50 years from 1961 to 2011 have been obtained from the Statistical Yearbook, databases The Ministry of Agriculture, the Center for Statistics of Iran and the FAO Database.
Agronomic index was used to study the land use status of arable land and an aspect of compression including land cover with one-year cultivars.

Based on the average, total agricultural density in 1971, 2004 and 2011were 9.26, 8.48 and 8.80, respectively, and the mean of three years was 8.94 months. The lowest index of agricultural density index in 1350 belonged to southern coastal provinces (Hormozgan and Bushehr) and Mazandaran with average of 6.98 and 7.33 months, respectively. In 2004 Guilan and Mazandaran provinces had the least index of 4 and 62.5 months, and in 2011 the lowest rate of this indicator was in Gilan and southern coastal provinces, with a period of coverage of 63.6 and 5.3 months, respectively. Considering that in most regions of the country more than half of the cultivated area is allocated to wheat, and also wheat remains on the ground  longer than the other crops, therefore, wheat cultivation owns the most important share  in the determination of the index of agronomic agglomeration (or crop cover). On the other hand, in the northwestern regions due to climatic conditions and colder periods of time, cereals especially wheat remail on the ground longer ,so the main reason for the higher index of agronomy in these areas is that wheat is present at the surface of earth. The study of agronomy in the country's arable crops showed that, contrary to expectation, in areas with higher rainfall the duration of land cover is less and soil remains without cultivation a long time in the year, due to the cultivation of crops such as rice. Therefore, changing the pattern of planting is essential in these areas .

The results of this study showed that due to the dominance of cereal cultivation in cropping pattern, crop density was affected by the cropping area of ​​these plants. Food security is one of the basic needs and increasing the production per unit area isone of the important ways to achieve it.  So, changing the pattern or planting system is necessary in areas where compression is low.

Tomato (Solanum lycopersicum L.) is a warm season crop that originated in South America. Tomatoes have significant nutritional value. In recent years, they have become known as an important source of lycopene, which is a powerful antioxidant that acts as an anticarcinogen. They also provide vitamins and minerals and serve as an important source of nutrients in contemporary diets due to readily available fresh fruit and processed products, their popularity, and the sheer volume consumed. Among the various factors affecting plant growth, optimum planting pattern plays an important role in preventing plant competition and poor fruit formation. Tomatoes can be planted in one of many different arrangements that provide adequate space for plant growth. Optimum use of nitrogen is one of the most important agricultural management factors in achieving proper performance in arid areas. Nitrogen use efficiency is greatly influenced by nitrogen levels and has an inverse relationship with the amount of nitrogen applied. The aim of this study was to investigate the effect of planting pattern (single row and twin row) and nitrogen levels on yield, yield components and nitrogen use efficiency of tomato cv. Karoon under arid region.
 

Two experiments were carried out at Bondarooz and Saad Abad agricultural research stations in Bushehr Province during 2017-18 to determine the best planting pattern and nitrogen fertilizer application on yield and its components of tomato cv. Karoon. The design was conducted as split plot layout based on a randomized block design with three replications. The main plot included plant pattern treatments in two levels (single row and twin row) and subplot included nitrogen treatments in four levels (no fertilizer, 90, 180 and 270 kg.ha-1). The studied traits included total fresh fruit yield, marketable fruit yield, total and marketable fruit per plant, fruit weight, fruit shape index, fruit hardness, chlorophyll index, and nitrogen use efficiency. For statistical analysis, analysis of variance (ANOVA) and Duncan’s multiple range test (DMRT) were performed using SAS ver. 9.1 software.
 

The results showed that the effect of region, planting pattern and nitrogen levels on the traits of total and marketable was significant at 1% probability level. The interaction effects of planting pattern and nitrogen levels on total fruit yield, marketable fruit yield, total number of fruits, chlorophyll index and fruit hardness were significant. The highest and the lowest total and marketable yields were obtained from single row planting method and application of 180 kg net nitrogen per hectare (54.08 and 46.50 t.ha-1) and twin row planting with non-application of nitrogen fertilizer (26.10 and 21.72 t.ha-1), respectively. The maximum number of fruits was 36.57 from single row planting and 180 kg Nitrogen fertilizer and the lowest number was 16.15 from twin row planting and without nitrogen fertilizer application. One of the reasons for this superiority can be the lower plant space in single row planting rather than twin row planting. The results of combined analysis of variance showed that only place effect on single fruit weight was significant at 1% probability level. The treatments with the highest chlorophyll index also had higher yields. Generally at all levels of nitrogen applications and interaction between planting pattern and nitrogen levels, nitrogen use efficiency decreased with increasing nitrogen fertilizer application. It may be related to limitation in uptake and sink capacities resulting in a saturation response. In Saad abad, simple effects of planting pattern and nitrogen on fruit weight had a significant effect at 5% probability level.
 

Single row planting was superior to twin row planting on all traits except fruit hardness. Nitrogen in arid regions can be considered as one of the most important factors affecting the performance and efficiency of nitrogen use. Single row planting and 180 kg Nitrogen application compared to a twin row planting without nitrogen increased the yield by 107%.

Sugarcane (Saccharum officinarum L.) cultivation as a strategic product with a high sugar content and having side products can play a major role in addressing this need and disconnecting dependence. Life cycle assessment in recent years has become an appropriate tool for assessing environmental impacts in agricultural and food industries. The purpose of this study was to evaluate the environmental impacts of sugarcane production in Imam Khomeini Sugarcane Agro-Industrial Company (IKSAIC) with the life cycle approach and predict the amount of contaminants released according to inputs using artificial neural network.

This research was carried out in IKSAIC as one of the seven companies affiliated to the sugarcane development and related industries of Khuzestan province during 2017-2018. In a life cycle assessment project, all production processes of a product, from the stage of materials extraction to disposal of the remaining waste from the product (from cradle to grave) are reviewed and the results of the reduction of environmental degradation are used.
Each life cycle assessment project has four essential steps as follows:
Goal and scope definition
Life cycle inventory
Environmental impact assessment
Interpretation of

Artificial neural network models were used to predict the environmental contamination of the product due to different inputs used in sugarcane production for plant and ratoon farms.

Assessment of environmental impacts of sugarcane production
In order to evaluate the reduction of environmental pollutants in sugarcane production, the entire life cycle of the product was investigated from primary sources extraction to harvesting in a field at plant and ratoon farms, separately. Ecoinvent databases were used to access needed information and data analysis was done with Simapro software.
In this study, the global warming potential per product in plant and ratoon farms is estimated to be equal to 126.51 and 103.95 kg CO2, respectively, which is due to the burning of sugarcane branches before harvest. The studies also show that agricultural machinery and electricity have the most impact on this sector.
In order to better interpret the results of the other functional unit, it was considered as a unit of land. This means that all indicators were calculated per hectare of production. When the functional unit is calculated on the unit basis, the differences in the products are ignored for the different performance levels in the results.
Assessment modeling of environmental emissions sugarcane production
Based on the results, in modeling for sugarcane production in plant farms, 9-10-5-10 structures with nine inputs, two hidden layer with 10 as well as 5 secret neurons and 10 output parameters were identified as the best structure. For this structure, R2, RMSE and MAPE were calculated. While the R2 coefficient for the human toxicity index and the marine aquatic eco-toxicity were obtained with the lowest values of 0.960, RMSE for these indices were calculated as 0.138 and 0.126 respectively. Furthermore, highest values of R2 coefficient for the acidification and eutrophication index of the lake were resulted about 0.992, whereas RMSE were computed about 0.106 and 0.115) respectively. Also, in modeling for sugarcane production in ratoon farms, the structure of 7-9-6-10 with seven inputs, two hidden layer with 9 and 6 secret neurons, and 10 output parameters are determined as the best structure. For this structure, R2, RMSE and MAPE were calculated and R2 coefficient was obtained with the lowest value of 0.985, while RMSE for this index was 0.164. In addition, R2 for the acidification index was calculated with the highest value of 0.995, whereas the RMSE for this index was calculated to be 0.116.

The results of the evaluation of product life cycle showed that the global warming potential in plant and ratoon farms was estimated to be 126.51 and 103.95 kg CO2, respectively. Results of artificial neural network modeling indicated that the best structure of the neural network to predict the environmental contaminants of sugarcane production, is 9-10-5-10 and 7-9-6-10 for plant farms and ratoon farms respectively.
Acknowledgements
Thanks and appreciation from the Department Agricultural Machinery Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran for the credibility of this research, as well as the officials and engineers of Imam Khomeini Sugarcane Agro-Industrial Company (IKSAIC).

Inappropriate use of chemical inputs damages soil beneficial microorganisms and consumer health. In order to reduce or eventually eliminate chemical inputs, bio-agroecosystems was founded. Azospirillum is one of the most studied genera as nitrogen fixing bacteria in agroecosystems. About 70 percent of the experiments have demonstrated the Azospirilum ability for increasing crop yield. Furthermore, some studies have shown that Azospirilum has a stress-reduction mechanism. Therefore, it seems that the Azospirilum is a suitable microorganism for low yielding conditions (water and N) of southern Iran. On the contrary, with respect to the importance of soil organic matter for microorganisms survival, its deficiency in soils of southern Iran is the biggest challenge for using the microorganisms as biofertilizers. Also, experiments on the interactive effects of crop residue, water deficiency and N sources (biological or chemical) on barley yield are quite scarce in southern Iran. Therefore, the aims of this study were to investigate the effects of crop residue management, different N sources (such as biological and chemical) and water stress conditions on barley yield in arid conditions of southern Iran (Fars province).

This research was conducted at the experimental farm of the Darab Agricultural College of Shiraz University during the 2017-2018 growing season. A split factorial layout based on a randomized complete block design with three replications was used. Treatments included: two irrigation levels as the main plots [1. Normal (IRN): irrigation based on the plant's water requirement up to the physiological maturity and 2. Deficit irrigation (IRDI): irrigation based on the plant's water requirement up to the anthesis stage (cutting of irrigation after anthesis)]. Also, subplots were two levels of plant residues [1. without residue, 2. returning 30% of wheat residues to soil] and four fertilizer sources [N0, no nitrogen fertilizer (control) ;N100, 100 kg N ha-1; Bio + N50, Biofertilizer (Azospirillum brasilense) + 50 kg N ha-1 and Bio, Biofertilizer (Azospirillum brasilense)]. Biological yield and grain yield, yield components, plant height, spike length and chlorophyll content of flag leaf were measured. Then, the harvest index was calculated. Data were analyzed by using SAS 9.1 software and the means were separated using Duncan’s multiple range test at 5% probability level.

The results showed that the cutting of irrigation after anthesis could cause severe water stress in the grain-filling period of the barley life cycle and consequently reduction of 1000-seed weight, the number of seeds per spike and the number of fertile tillers per m2. The interaction effect of irrigation regime × N fertilizer source on grain yield was significant at 1% probability level. The highest grain yield was achieved in IRN and Bio + N50 (4049 kg ha-1). Water stress reduced grain yield at all N fertilizer sources as compared with IRN. However, this reduction was different in N fertilizer sources (24.1%, 46.8%, 44.3% and 22.1% in N0, N100, Bio + N50 and Bio, respectively). With respect to the lowest amount of grain yield reduction due to water stress in Bio and then in N0 treatments and economic considerations, N0 treatment can be recommended for use in the cutting of irrigation after anthesis (IRDI) strategy.

According to the results of this study, the highest barley grain yield achieved by the integrated N fertilizer [Biofertilizer (Azospirillum brasilense) + 50 kg N ha-1] in normal irrigation. Deficit irrigation after anthesis significantly decreased barley grain yield at all N sources. Therefore, this irrigation regime was not recommended for barley farms of southern Iran. But if farmers intend to the cutting of irrigation after anthesis because of water resources deficiency, with respect to the lack of significant difference among N sources in this condition, it is recommended that no N fertilizer is applied.

Agricultural intensification has had negative effects on the environment. The sustainability in the agricultural systems that provides sufficient food on the one hand and maintains the quality of the environment on the other hand, is very important. In assessing the sustainability of agricultural systems, the contribution of both environmental and economic resources must be taken into account. Emergy analysis has many indices in which the efficiency, renewability, environmental burden, and sustainability of a system can be assessed in terms of environmental and economic. The purpose of this study was to evaluate and compare the resource use efficiency and sustainability indices for two autumn and spring potato systems and provide suggestions for optimum and sustainable management of the crop.

In this study, two production systems of potato were evaluated using emergy sustainability indices in Gorgan County, Iran during the period of 2017-2018. To this end, 100 and 60 farms were selected for autumn and spring potato, respectively. To analyze the production systems, the spatial and temporal boundaries of the system were defined and resources were divided into four categories: renewable environmental sources (R), nonrenewable environmental resources (N0), purchased renewable resources (FR), purchased nonrenewable resources (FN). Emergy flow for each item was multiplied by their transformities in joules and grams. In this study, emergy indices were calculated and compared by t-test between warm and cool production systems.

Total emergy inputs for the autumn and spring potato production were estimated as 1.71E+16 and 1.76E+16 sej ha-1 year-1, respectively. In autumn potato production, dependence on purchased inputs was higher than environmental inputs, while in spring potato production, the dependence of environmental inputs was higher than purchased inputs. Groundwater emergy was the largest emergy inputs of the total in both autumn and spring potato production systems with a share of 23.92% and 45.28%, respectively. In autumn and spring potato production system, transformities were 1.50E+05 and 2.54E+05 sej j-1; emergy renewabilities were 22.85% and 12.78%; emergy yield ratios were 1.44 and 2.06; emergy investment ratios were 2.29 and 0.94; environmental loading ratios were 29.10 and 30.02; and emergy sustainability indices were 0.05 and 0.07, respectively. There is a significant difference between the emergy indices of the autumn and spring potato production systems. Despite the higher contribution of environmental resources in the spring potato production system, the high consumption of groundwater as a non-renewable input led to an increase in environmental burden. The use of new irrigation methods will improve water consumption and, as a result, reduce environmental pressure on ecosystems. The autumn production system was more favorable in terms of yield and resources use efficiency, renewability and environmental sustainability than the spring production system. The economic sustainability of the autumn potato production system was slightly lower than that of the spring potato production system, largely due to the unreasonable use of purchased inputs such as seed and fossil fuels. Optimum management of inputs such as seed and fossil fuels will increase economic sustainability in the autumn potato production system. The optimization of economic inputs will increase economic sustainability in production systems (Kohkan et al., 2017).
 

Two autumn and spring potato production systems in Gorgan had significant differences in terms of resources use efficiency, input renewability, environmental burden and ecological sustainability. The autumn potato production system was more favorable in terms of resources use efficiency and environmental sustainability. The economic sustainability of the autumn potato production system was slightly lower than that of the spring potato production system. Optimizing inputs through the use of appropriate seeds (size and recommended amount), the use of soil tillage and modernization of machinery and diesel engines of the well will increase the economic sustainability of the autumn ecosystem.

Intercropping, i.e. growing two or more crops together on the same land at the same time. The intercropped legumes/cereal systems reduce inter-specific competition by enhancing complementarity/facilitation processes thereby improving the exploitation of environmental resources; on the other hand, it has led to improved crop production, which is due to greater efficiency in the intercropping system. Salehi et al. (2018) in intercropping of triticale with annual legumes reported that the highest plant height, number of spike per m-2, spikelet number per spike, grain number per spike, grain and biological yield of triticale were obtained in the sole crops but the lowest economic yield of triticale was achieved from intercropping of triticale with vetch, respectively. The purpose of this study was to investigate the response of growth, yield and yield components for different fababean cultivars affected as in intercropping with triticale in order to achieve the most suitable combination in terms of maximum yield and land use efficiency in Urmia weather conditions.

In order to evaluate yield and yield components of different faba bean varieties in intercropping with triticale, a field experiment was conducted based on a randomized complete block design with thirteen treatments and three replications at the Research Farm of the Faculty of Agriculture, Urmia University, Iran, during the growing season of 2018. Treatments were included sole cropping of triticale, replacement intercropping of triticale with five-faba bean varieties (Mahta, Histal, Feyz, Barkat, Luzde otono and Shadan) in ratios 1:1. Triticale was harvested when spike turned brown and different faba bean varieties were harvested when the first pod of the plants fully matured. Field data were collected by cutting 10 plants randomly from each plot and yield component of each plant was considered as the average for each plot. Analysis of variance (ANOVA) was performed using SAS software; version 9.4 (SAS Institute Inc., Cary, NC, USA) and significant differences between treatments were compared with the Duncan test at P≤0.05.

The results showed that the highest plant height, spike length, number of spike per m-2, spikelet number per spike, grain number per spike, grain and biological yield, and chlorophyll a and b contents of triticale were obtained in the intercropping system. Also, the maximum nodule number, nodule dry weight, plant height, length pods, number of seeds per pod, 100- seed weight, seed and biological yield, and chlorophyll a and b contents of different faba bean varieties were achieved from intercropping and the lowest amounts of mentioned were recorded in the sole cropping of both plants, respectively. The higher seed yields of the intercropping systems compared to the sole cropping were probably due to the better use of environmental resources by balancing inter-specific and intra-specific interactions. The average chlorophyll content of both plants in the intercropping system was higher than the sole cropping. Increasing the chlorophyll content in the intercropping system was attributed to the better availability of nutrients, light, and water.  However, the partial LER of faba bean was higher than triticale, indicating that the former was the dominant plant in intercropping patterns. In addition, the highest LER total was calculated for intercropping triticale with Feyz faba bean (2.2 units) and the lowest total LER (1.9) was computed to the triticale with Barkat faba bean hat represents an increased advantage in intercropping than sole cropping.

Our study showed that the productivity of different faba bean varieties in intercropping with triticale could be increased by environmental conditions. The maximum seed and biological yield of both plants were obtained at intercropping. The LER was higher than one in all intercropping treatments compared to sole cropping systems. According to the results, it seems that the use of the intercropping system is remarkably effective to increase the economic income and land-use efficiency.

Many plant species in natural Iranian ecosystems such as Echium amoenum have high medicinal and economic potential use. The growing need for medicinal products of this plant along with the increasing domestic consumption, export and prevention of its extinction due to its over harvesting from natural ecosystems, necessitates its mass cultivation. E. amoenum is one of the medicinal plants that has important compounds in its flowers, which is necessary to increase the quantity and quality of its flowers. In general, environmental and management factors affecting canopy structure have a significant effect on flower production in these plants. Therefore, for the successful cultivation of any medicinal plant, including E. amoenum, providing optimal environmental conditions such as the best fertilizer combination to meet the nutritional needs of the plant is a priority. Adding organic matter from various sources to the soil is one of the most common regenerating operations to improve soil properties.

In order to better understand the agronomical potential of E. amoenum as a medicinal plant at field condition, an experiment was conducted in a factorial layout based on a Randomised Complete Block design with three replications at Agricultural Research Station, Ferdowsi University of Mashhad, Iran during growing season of 2009-2012. The experimental treatments were all combination of four levels of organic fertilizers (cow manure (30 t.ha-1), compost (20 t.ha-1), vermicompost (5 t.ha-1) and control) and four plant densities (4, 6, 8 and 10 plants.m-2). In April 2010, bed preparation was done by ploughing and levelling the soil and fertilizer treatments were mixed with soil. Cultivation operations were carried out in the first week of May 2010. Irrigation was performed every seven days. During the growing season of 2010, the plants produced mild stems and spent the entire season as a rosette. By autumn and winter, the aerial parts of the plant were dried and in early March 2011, with increasing ambient temperature, the leaves of the plant began to reappear from the crown. Flowering of the E. amoenum in the second year, 12 months after sowing began on April 25, 2011 and the flowering period lasted one month. The flowers were harvested in four stages every seven days. Flowering of the plant began in the third year on May 15, 2012, and the flower harvesting was carried out in five stages, every five days. At each harvest stage, fresh flower yield, dry flower yield and number of flowers per five grams of flowers were determined. After flowering, three plants were randomly marked and plant height, number of main and lateral branches and number of flowers per plant were recorded.

E. amoenum has only vegetative growth in the first year. The results of second and third years showed that studied treatments had significant effect on plant height, number of main and lateral stem branches, number of flower per plant, fresh and dry flower yield. Result showed that by increasing of plant density, fresh and dry flower yield and number of flower (at five g) were increased but number of lateral stem branches and number of flower per plant were decreased. Application of organic fertilizers increased fresh and dry flower yield, plant height, number of lateral stem branches and number of flowers per plant. Additionally, the highest fresh and dry flower yield, number of flower and number of flower per plant and number of main stem branches were obtained in the first year but the highest plant height and number of lateral branches were observed in the second year.

Due to the fact that E. amoenum is an unlimited growth plant, therefore, proper density adjustment is especially important during reproductive growth period. Increasing density during this period causes the plant to have fewer resources (space, water and food) to increase vegetative growth and, as a result, establish a proper balance between vegetative and reproductive growth and produce more flowering shoots and increase flower yield will result. Overall, it seems that application of organic fertilizers and optimum plant density are among more important factors for E. amoenum flower production.
Acknowledgements
Conducting this research was funded by Ferdowsi University of Mashhad, Faculty of Agriculture (Grant No. 66, 25 May 2010).