نشریه بوم شناسی کشاورزی
سال پانزدهم شماره 2 (تابستان 1402)

Hyssop (Hyssopus officinalis) is a plant belonging to the genus Mint. The origin of this plant is reported to be Asia Minor and it goes from the Caspian Sea to the Black Sea as well as in the sandy areas of the Mediterranean. Usable parts of hyssop are flowering branches, leaves and seeds. Nowadays, the simulation models of growth and development have been used as suitable tools for acknowledging and analyzing the effect of plant, soil and atmosphere parameters for plants growth and development. Over the last two decades, FAO (Food and Agriculture Organization) has developed and successfully applied the agro-ecological zones (AEZ) methodology and supporting software packages to analysis solutions to various problems of land resources for planning and management for sustainable agricultural development at regional, national and sub-national levels. The issues addressed include linking land-use outputs with other development goals in such areas as food production, food self-sufficiency, cash crop requirements, issues of soil fertility constraints, soil erosion risks and land degradation. This procedure can calculate and present the potential biomass production of any crops under specific climatic condition using climatology parameters. FAO has presented the procedure manual of AEZ Package as a guideline to analyze land suitability for any crops. So, the current research is done to investigate the optimum planting date and forecast the biomass production of Hyssop using the AEZ model.

 The experiment was conducted as a split-plot in a completely randomized block design with six planting dates and three replications in 2017-2018. The main factor was different levels of nitrogen fertilizer: 0, 50, 100 and 150 kg/ha and sub-factor was planting dates between 30-day periods from October 17 to March 25. The data of this experiment were used to calibrate the model of AEZ and the data of two years of planting date experiments in the period 2016-2017 were used to evaluate the model, so that the data collected in the first year were used for calibration and the data of the second year were used for evaluation. The index of Physiological Days (PDays) was used for analyzing photoperiod response of Hyssop during different planting date. The procedure of Soltane et al., (2006) was used to calculate PDays index.

 The AEZ model evaluation results showed that the RMSEn value of the predicted biomass was 10.81%, and the efficiency index (E), the Hyssop adaptation index (D) value, the coefficient of residual mass (CRM) value in the first year for the predicted value was 0.999, 0.98 and 0.06, respectively. The coefficient of determination (R2) was obtained by linear regression analysis of functions between the actual and simulated values in the first year (R2=0.98). The RMSEn, (E), (D) and (CRM) values for the predicted biomass in the second year were 5.96, 0.999, 0.0454 and 0.98%, respectively. These results indicate that the simulated and real values are in good agreement. Consequently, the model simulated the biomass with high accuracy. The results of biomass and yield analyzing using AEZ model indicated limited growth period with in a period in Jiroft station can be occurred from May to September 21, at this period, the plant stops growing and the yield decreases. Based on model estimation values for other related climatology stations: the highest biomass yield for Bam climatology station (2321.9 kg/ha and 23550.2 kg/ha respectively) can be September to early October, the cold stress limitation can be occurred at the planting date from December 1st to February 3th and the heat stress can be occurred on July planting date. In Kahnuj station, limited growth period with high temperature can be occurred from Early May to September 11, the highest biomass performance can (19413.9 kg/ha and 19764.3 kg/ha respectively) be obtained at the planting date from October to early November.

 Given the ability of the AEZ model to analyze the hyssop plant production system, which is able to simulate the effect of different c
limatic, climatic, soil, managerial and plant variables on plant growth and yield, this model can be widely used in different regions as He used an important decision-making and management tool in research and executive dimensions.

In recent years, due to the excessive consumption of agricultural inputs, especially chemical fertilizers and common methods of crop production, problems have arisen that have led to more attention to sustainable agriculture.Zeolite is one of the natural minerals that also has nutritional value and can be considered a step towards achieving sustainable agriculture.

In order to investigate the effect of type and amount of zeolite on the yield of common millet, an experiment was conducted in the crop year of 2017-17 at the research farm of the Faculty of Agriculture of Birjand University. This factorial experiment was performed using randomized complete block design with 3 replications. Experimental treatments included two types of calcium and potash zeolites in two forms of powder and granules, which were considered at two levels (5 and 10 tons per hectare) with a control treatment without zeolite. In this study, common millet (Pursu) was used for cultivation.

Number of clusters per plant: Analysis of variance of data showed that the effect of treatment on this trait was not statistically significant at the level of 5% probability. However, the control treatment had fewer clusters than the potassium powder and granular treatments of 10 tons per hectare and the calcic powder and granule treatments of 10 tons per hectare. Also, the control treatment had more clusters than the calcium granular and powder treatments of 5 tons per hectare and the potassium granular and powder treatments of 5 tons per hectare. Comparison of the average effect of zeolite content on the number of clusters per plant showed that increasing the application of zeolite from 5 tons per hectare to 10 tons per hectare caused a significant increase in the number of clusters per millet plant at a probability level of 5%.
Thousand-grain weight: Analysis of variance of 1000-grain weight data as a treatment, to compare with the zeolite control treatment showed that the effect of zeolite treatment on millet 1000-grain weight was significant at 5% probability level. The results of factorial analysis of variance showed that the simple effect of zeolite type on 1000-grain weight was significant at 5% probability level. But the simple effect of zeolite content as well as the interaction effect of type and amount of zeolite on this trait was not significant.
Grain yield: The results of analysis of variance of grain yield data to compare treatments containing zeolite with control treatment without zeolite showed that the effect of zeolite treatment on grain yield was significant at the level of 1% probability. The results of factorial analysis of variance showed that the simple effect of zeolite content at 1% probability level and the effect of type and amount of zeolite at 5% probability level on grain yield were significant. But the simple effect of zeolite type had no significant effect on this factor. The results of comparing the average amount of zeolite on grain yield showed that increasing the amount of zeolite increased millet grain yield at a probability level of 5%.
Water use efficiency: The results showed a significant effect of zeolite treatment on water use efficiency at a probability level of 1%. The results of variance for water use efficiency showed that this trait was significantly affected by the simple effect of zeolite content and the interaction between type and amount of zeolite at 5% level but the effect of zeolite type on it was not significant. The results of comparing the average amount of zeolite on water use efficiency showed a statistically significant difference between the application of 5 and 10 tons per hectare of zeolite at the level of one percent.

The results showed that the application of different types of zeolite caused a significant increase in 1000-grain weight and number of grains per panicle at a probability level of 5% and grain yield, water use efficiency at a probability level of one percent compared to control treatment (no application of zeolite). Increasing the application of zeolite from 5 to 10 tons per hectare significantly increased the number of spikes per plant, number of seeds per spike, 1000-seed weight, biological yield, grain yield and water use efficiency. Therefore, with the optimal using of this fertilizer, the effects of drought stress on plants are somewhat reduced and it is recommended for using in dry areas.

Today, increasing sustainability in agriculture is essential to meet future food needs. In this regard, the intercropping culture has been considered as viable and environmentally friendly approach to sustainable agriculture. Further, investigation of complementary species relationships in annual cropping systems could be addressed to achieve sustainability and development. In order to fully understand the inter-specific interactions between crops, it is crucial to know how to react to neighboring species. The selection of species with the different spatial structures in the intercropping culture pattern can be helpful in this regard. The differences of crop’ canopy in intercropping cultivation increase the efficiency of using water, light, and nutrients as well as facilitating inter-species competition. Therefore, this study investigated the competition between soybean and Niger seed on yield and yield components, radiation efficiency, and yield advantage in the intercropping cultivation system.

A field experiment was conducted in two years (2018-19) at the Research Farm of Sari Agricultural Science and Natural Resources University, Iran (33º, 36ʹ N, 53º, 03ʹ E with 43 m altitude). The experiment was done based on a randomized complete block with four replications. The experimental treatment was 75% soybean + 25% Niger, 50% soybean + 50% Niger, 25% soybean+75% Niger based on the replacement method and soybean monoculture (100:0) and Niger monoculture (0:100). For example, a 25:75 combination included around three rows consisting of sowing a soybean and one row of Niger, along with vice versa in the 75:25 combinations. The 50:50 combinations also included planting two rows of each studied crops. The seed was sown directly on the 5th of May with a density of 28 plants per square meter. This study was investigated agronomic traits, radiation use efficiency, and the impact of competition on intercropping using Hill and Shimumoto models.

Based on the achieved results, different planting ratios significantly affected plant height, dry weight, radiation use efficiency, yield, and yield components of both crops. The highest shoot heights of soybean and Niger with an average of 76.3 and 189.7 cm were related to planting ratio of 75:25, respectively. Also, the number of pods per plant of soybean and the number of capitule per plant of Niger in intercropping cultivation increased compared to monoculture. The reduction in the share of soybean and Niger sowing rows in different intercropping ratios increased the crop yield components. Also, the shoot’ dry weight of both crops increased in different planting ratios compared to the expected values. The highest percentage of dry shoot weight in soybean and Niger was related to 25:75 and 75:25 planting ratios, respectively. Besides, during different stages of growth, the radiation use efficiency of Niger in planting ratio was 50:50 and 25:75 higher than soybean. Also, the amount of radiation use efficiency in intercropping cultivation was more elevated than in monoculture. Due to the growing trend in its amount compared to the expected values, the effect of competition on radiation use efficiency during different growth stages was the type of mutual co-operation. According to the results, soybean (100:0) and Niger monoculture (0:100) had the highest and lowest grain yield with an average of 4965.7 and 462.4 kg. ha-1, respectively. Among the different intercropping, the combination 75:25 with an average of 4173.73 kg. ha-1 had the highest grain yield. Finally, the average land equivalent ratio in all different intercropping ratios was more than one, and the planting ratio of 50:50 had the highest average yield (LER = 1.28).

Increasing resource utilization efficiency and establishing a mutual co-operation relationship is essential in improving the usefulness of Soybean and Niger intercropping cultivation compared to monoculture. Furthermore, the selection of Niger in intercropping systems can be beneficial due to their morphological features and facilitation of competition.

One of the factors affecting the growth and development of crops is the cultivation pattern, which affects the distribution of plants in the field, distances between plants, the use of growth sources such as light, water and soil nutrients, and competition between plants. These factors affect the growth and yield of crops. Also, using compost fertilizer has beneficial effects on physical, chemical and biological conditions of the soil and has positive effects on grain yield and yield components of crop plants. This study designed and carried out with aim to study the effect of planting method and sugarcane residue compost fertilizer on yield and yield components of corn and some soil properties in Ahwaz weather conditions at Agricultural Sciences and Natural Resources University of Khuzestan.

In order to investigate the effect of planting method and sugarcane residue compost fertilizer on yield and yield components of corn (hybrid of single cross 703) and some soil properties, a field experiment using a split-plot arrangement accomplished based on the randomized complete block design with four replications in Mian-Ab region of Shooshtar on 2018. Experimental factors were include four planting method (single row on ridges, on watermark, in furrows and on flat ground) as a main factor in main plots and four amounts of sugarcane residues compost (0, 10, 20 and 30 t ha-1) as a sub factor in sub-plots. Each sub-plot had 6 planting rows with a length of 3 meters and a width of 4.5 meters (with an area of 13.5 square meters). The seeds were planted manually at a depth of 3 cm at 2nd August 2017 with a density of 66000 per ha (the distance between ridges and furrows was 75 cm and the distance between the plants was 18 cm). In this experiment row number per ear, grains per row, thousand grain weight, grain yield, biological yield, harvest index, soil nitrogen percent and soil organic matter percent were measured.

The analysis of variance showed that the effect of plant method, sugarcane residue compost and their interaction were significant on the traits of row number per ear, grain number per row, thousand grain weight, grain yield, biological yield, harvest index, soil nitrogen percent and soil organic matter percent. The comparison of mean showed that the maximum amount of corn traits were obtained in furrow planting and using 30 t ha-1 of sugarcane residue compost and the lowest amounts were observed in ridge planting and non-use of sugarcane residue compost. So that, mean comparison of grain yield under the interaction of planting method and sugarcane residue compost showed that the highest grain yield (6497 kg ha-1) was in furrow planting and 30 t ha- of sugarcane residue compost and the lowest grain yield (3870 kg ha-1) was in ridge planting and non-use of sugarcane residue compost. Examination of correlation coefficients between the measured traits showed that grain yield had a more positive and significant correlation with biological yield, harvest index and 1000-grain weight. Also, biological yield had a more positive and significant correlation with grain yield, 1000-seed weight and number of rows per ear.

In general, the findings of this experiment demonstrated that the furrow cultivation method resulted in the highest values for the measured traits (excluding soil nitrogen and soil organic matter percentage). Moreover, across all cultivation methods, an increase in the application of sugarcane residues compost fertilizer, as well as the availability of water and nutrients for the plants, led to an increase in the magnitude of these traits. The maximum values were achieved at a compost fertilizer rate of 30 t ha-1. Based on the results of this experiment, it can be concluded that cultivating corn using the furrow method and applying 20 to 30 t ha-1 of sugarcane residue compost can significantly enhance corn grain yield in the Shooshtar region.

Ecosystem services are usually divided into four categories: (a) provision services, (b) regulating services, (C) cultural services and (d) supporting services. Ecosystem services are managed in agroecosystems primarily for food production. But, agricultural ecosystems provide provision, regulating and cultural services for human society. These services respond strongly to human socio-economic needs. Quantifying the various services and functions of agroecosystems is one of the most important effective strategies in order to increase attention pay to these services. Therefore, the purpose of this study was evaluation and quantification of ecosystem services in wheat (Triticum aestivum L.) agroecosystems of Dasht-e-Naz, Sari.

This experiment was performed as an unbalanced completely design in wheat agroecosystems of Dasht-e-Naz, Sari (Mazandaran province), during 2019-2020. In this study, 9 wheat plots with 4 cultivars including Tirgan, Ehsan, Collector and N-92-9 were surveyed and monitored. In this study, some ecosystem services such as insect and weed biodiversity (using Shannon-Weiner, Simpson, Margalf, Uniformity and Menhinick indices), soil microbial respiration, carbon sequestration, organic matter, abundance of earthworms, grain yield, protein content oxygen production, and soil protection (by the stability of aggregates) were evaluated and quantified. Soil samples were taken from a depth of 0-30 cm before wheat planting in November 2019 and after harvest in June 2020 for assessment of rate of microbial respiration, organic matter and carbon sequestration. Also, oxygen production was estimated based on net primary production. Sampling of yield and plant biodiversity was harvested based on W pattern and with quadrate 0.5 × 0.5 m2. All samples were moved to the crop research laboratory of Gorgan University of Agricultural Sciences and Natural Resources and the plant flora was determined by genus and species names.

The results showed that crop management and performance of intensive agricultural system were effective on providing many services of ecosystems in wheat fields of Dasht-e-Naz, Sari. These services are influenced by several factors such as cultivar type, crop rotation, tillage, etc. The results showed that the effect of different cultivars was significant on grain yield and protein percentage. The highest percentage of grain protein as a provision service was obtained from Ehsan cultivar (12.15%) and the lowest content was obtained about 11.42% from N-92-9 cultivar. The highest wheat grain yield and oxygen production were calculated from plots under Collector cultivar. In additional, the highest amount of carbon sequestration (2.33 ton/ha) and microbial respiration rate in before planting and after harvest (76.46 and 38.52 mg CO2 per kg of soil per day, respectively) belonged to plot 15. Also, it was determined that plot 15 was better than other plots from soil protection service view based on the diameter mean weight index (MWD) and the geometric mean diameter index (GMD). In this research, three beneficial insects (biodiversity assessment) were observed such as Coccinella septempunctata Linnaeus and Aphidius matricariae, and Chrysoperla carnea. The highest values of Shannon-Weiner and uniformity indices of weeds were as 2.63 and 0.82 in plots 23 and 15, respectively. Furthermore, Shannon-Weiner and uniformity indices of insect communities were obtained as 2.07 and 0.94 from plot 22, respectively.

 Generally, carbon sequestration, organic matter, microbial respiration, earthworm abundance, aggregate stability index, average weight diameter (MWD) and geometric mean diameter index (GMD) were better in plots 14 and 15 under wheat cultivation  than other plots. The results of this study showed that crop management and implementation of intensive agricultural system were effective in providing many ecosystem services in wheat fields in Dasht-e Naz region of Sari. So that, these services were affected by several factors such as cultivar, crop rotation and tillage methods.
Acknowledgment
The authors gratefully acknowledge the financial support of Gorgan University of Agricultural Sciences and Natural Resources and Dr. Hamid Sakinin for his help.

 Occurrence of drought and reduction of rainfall in the future will limit the cultivation of irrigated crops. Thus, it is probable that a part of the present irrigated lands and orchards of Iran may be unavailable for the cultivation of irrigated crops, but it is possible to cultivate rainfed crops in these lands. However, the available potential for cultivation of rainfed crops with respect to the soil type, climate and other factors is not known. Limited water resources, on the one hand, and the growing population along with increasing the need to produce food, on the other, make it necessary to have a comprehensive, practical and accurate program. Therefore, research on this issue is essential. In this study, production potential of rainfed wheat (Triticum aestivum), barley  (Hordeum vulgare L.), chickpea (Cicer arietinum L.), lentil (Lens culinaris Medik) and canola (Brassica napus)  in irrigated lands (fields and orchards) was modeled.

  Weather stations (position and distribution), long-term weather data (15 to 30 years), HC27 soil map, crop management data plant parameters were used to determine the yield in this study using SSM-iCrop2 model. In each zone, the yield was determined and compared with the actual data. In other words, the model output were compared with the actual current rainfed yields of each province and then it was determined that whether the model precision was sufficient for this study. Other calculations (determining the average yield of provinces) and generation of maps were done using ArcGIS V.10.2. The yield obtained by farmers in these lands was considered as 50 and 70 percent of yield potential. Also, the yields were categorized into four classes of excellent, good, medium and non-suitable. This classification is based on economic- agronomic profit of crop harvest.

 The results of this study showed that the conditions of rainfed production in each province of the country is suitable/appropriate for some crops and unsuitable/inappropriate for some other. In case the yield of farmers reached 70 percent of yield potential by optimum management, all provinces will be classified into the upper average group (3, 18 and 10 provinces in excellent, good and medium groups) for wheat. For barley 30 (3, 10 and 17 provinces in excellent, good and medium groups), for chickpea 30 (3, 6 and 21 provinces in excellent, good and medium groups), for lentil 31 (13 and 18 and 10 provinces in good and medium groups) and for canola 30 (4, 5 and 21 provinces in excellent, good and medium groups) provinces will be placed in the upper average group. Based on 70 percent of yield potential of canola, barley and chickpea, only on province is placed in non-suitable group. On the other hand, in case the yield of farmers reaches 50 percent of yield potential due to improper management, for wheat 30 (2, 2 and 26 provinces in excellent, good and medium groups), for barley 28 (4 and 24 provinces in good and medium groups), for chickpea 18 (4 and 14 provinces in good and medium groups), for lentil 28 (3 and 10 provinces in good and medium groups) and for canola 25 (5 and 20 provinces in good and medium groups) will be classified into the upper average group. Based on 50 percent of yield potential of rainfed wheat, barley, canola, chickpea and lentil, 1, 3, 6, 13 and 3 provinces were placed in non-suitable group, respectively.

 According to the results of this study, a major part of the provinces will be placed in medium and non-suitable groups in case of improper management, and agricultural productions will not satisfy the needs of the country. Therefore, it is necessary to pay a special attention to agronomic management of rainfed crops, as the agricultural production of the country will not be acceptable unless 70 percent of yield potential is achieved.

Sustainability in agriculture at regional scale is about balancing food security with maintaining environmental health. Therefore, agricultural operations are sustainable when they maintain the health of the environment, the interaction between plant and animal production, social acceptance and economic benefits (Kumaraswamy, 2012). Excessive use of environmental resources and excessive consumption of chemicals in agriculture have caused environmental problems and reduced sustainability (Quintero-Angel & Gonzales-Acevedo, 2018). Therefore, it is necessary to study the patterns of energy consumption and efficient use of energy in agriculture, which is one of the basic principles in sustainable agriculture. Emergy analysis, as suitable tool for this purpose, is used in the various ecosystems (Odum, 2000; Brown & Ulgiati, 2004). Emergy analysis is able to determine the degree of sustainability of connected ecological and economic systems. Emergy indices are effective tools for integrating ecological-economic systems and make it possible to measure and compare all aspects of these ecosystems (Patterson et al., 2017). The purpose of this study was to evaluate sustainability indices for rapeseed (Brassica napus L.) production systems using emergy indices and provide suggestions for sustainable product of the crop in Kalaleh county. 

In this study, production systems of rapeseed were evaluated using emergy sustainability indices in Kalaleh County (Golestan province), during the period of 2018-2019. For this purpose, 50 rapeseed fields were selected as Cochran equation. First, the spatial and temporal boundaries of the system were defined (Odum, 1996; Odum, 2000) and resources were divided into four categories: renewable environmental resources, nonrenewable environmental resources, purchased renewable resources and purchased nonrenewable resources (Amiri et al., 2019). Emergy flow for each input was multiplied by their transformities in joules and grammes (Odum, 2000). Finally, emergy indices such as renewability, emergy yield ratio, emergy self-support ratio, environmental loading ratio and emergy sustainability index were calculated and evaluated in rapeseed production systems. 

Total emergy input for the rapeseed production was estimated as 1.64E+16 sej ha-1 year-1. In rapeseed production, dependence on environmental and nonrenewable inputs was higher than purchased and renewable inputs. Soil erosion emergy was the largest emergy inputs of the total in rapeseed production system with share of 47.31%. Also, fossil fuel emergy was the largest emergy inputs of the purchased with share of 38.41%. In this research, we calculated the transformity equal to 2.59E+05 sej j-1, specific emergy equal to 7.33E+09 sej g-1, emergy renewability equal to 8.16%, emergy yield ratio equal to 2.17 and emergy investment ratio equal to 0.85. Also, emergy self-support ratio, standard environmental loading ratio, modified environmental loading ratio, standard emergy sustainability index, and modified emergy sustainability index were estimated 0.54, 13.81, 11.27, 0.16 and 0.19, respectively. Despite the higher contribution of environmental resources in the rapeseed production system, the high share of soil erosion as a non-renewable input along with the unreasonable consumption of some nonrenewable purchased inputs, such as fossil fuels, led to a decrease in renewability and an increase in environmental load. Based on evaluation of emergy indices, rapeseed ecosystem had the high production efficiency and resource consumption efficiency and it had the great potential to increase economic productivity. However, rapeseed production in Kalaleh county had low environmental and economic sustainability. The implementation of conservation tillage methods and the modernization of machinery can contribute to a reduction in the consumption of nonrenewable and economic inputs in rapeseed production ecosystems. This reduction in input consumption not only alleviates environmental pressure but also enhances sustainability. By prioritizing the use of renewable environmental inputs and minimizing the utilization of nonrenewable and economic inputs, the emergy sustainability index can be improved.

The rapeseed ecosystems exhibited high production efficiency and resource consumption efficiency, along with significant potential for increasing economic productivity. However, despite the substantial contribution of environmental resources in these systems, the prevalence of soil erosion as a significant portion of the total emergy input resulted in a decline in renewability, an escalation in environmental burden, and ultimately a decrease in sustainability. It appears that enhancing management methods to minimize the consumption of nonrenewable and economic resources would be effective in bolstering the environmental and economic sustainability of rapeseed farming ecosystems in Kalaleh county.

Intercropping cultivation is an excellent method to increase agricultural productivity per unit area based on environmental mechanisms. In this planting system, it is necessary to select crops with different capabilities in uptake resources and establish a complementary relationship. However, legumes in intercropping cultivation can be used an alternative and sustainable way to increase efficiency. Besides, it is necessary to study the interactions in the above and belowground parts to achieve the mentioned goals. Therefore, this study aimed to investigate inter-specific interactions in millet and soybean intercropping cultures.

A field experiment was conducted for two years (2018-19) at the research farm of Sari agricultural science and natural resources university, Iran (33º, 36ʹ N, 53º, 03ʹ E with 43 m altitude). The experimental design was a randomized complete block with four replications. The experimental treatment was 75% Soybean + 25% Niger, 50% Soybean + 50% Niger, 25% Soybean+75%Niger based on the replacement method and monoculture. This study investigated the agronomic traits, LAI, TDW, nitrogen derived from the atmosphere, and total microbial activity in the soil in different planting ratios.

The results showed that soybean monoculture had the highest plant height during different stages of growth. Furthermore, with the increase in the share of planting soybean in intercropping cultivation, the shoot height of the millet also increased. Also, unlike the millet, the soybean succeeded in producing more leaf area indexes among different mixed cultivation ratios than monoculture. The leaf area index of millet showed a significant decrease as the proportion of soybean plantings increased. However, despite this decrease, the total dry matter of soybean exhibited a higher percentage increase at various growth stages compared to the decrease in millet yield. As a result, after 60 days of planting, the intercropping cultivation of millet and soybean demonstrated positive complementarity in terms of competition impact. Additionally, the intercropping cultivation showed a higher percentage of nitrogen derived from the atmosphere compared to soybean monoculture. During the study period, the planting ratio of 75% millet and 25% soybean exhibited the highest increase in nitrogen fixation (Ndfa), with average values of 93.84% and 83.85% at 90 days after planting, respectively. Increasing the number of millet sowing rows in the intercropping patterns played a crucial role in intensifying competition with soybeans during the early growth stages and had an impact on the biological activity of soybeans. Moreover, the microbial activity in the soil (at a depth of 0-30 cm) was higher in the different intercropping ratios compared to monocultures of soybean and millet. In addition, soybean and millet monoculture had the highest and lowest grain yields. Among the different intercropping ratios, the 75:25 in 1398 with an average of 4639.77 kg. ha-1 had the highest grain yield. Besides, the planting ratio of 25:75 and 50:50, with an average of 1.23 and 1.02, respectively, had an LER higher than one. With increasing the share of soybean planting in intercropping, the competitiveness of the plant increases, and the competition ratio of millet was higher than the unit only in the planting ratio of 25:75 (millet-soybean). Therefore, the competitiveness of millet in mixed cultivation is significantly reduced by reducing the share of planting row. Finally, increasing productivity in the 25:75 combinations reduced soybean's competitive dominance, increasing millet grain yield in comparison to expected values and improving total microbial activity.

Due to limited growth period, millet had competition played an essential role in increasing total microbial activity and the percentage of nitrogen derived from the atmosphere at a 25:75 planting ratio before the initial reproductive growth. In addition, 25:75 and 50:50 planting ratios reduce soybean's competitive dominance, resulting in enhanced productivity. Finally, the selection of complementary plants based on physiological, morphological characteristics, and competitiveness in intercropping cultivation can be effective in the above and belowground interactions.

Hamedan province, characterized by an average annual rainfall of less than 340 mm, faces significant limitations in potato production)Solanum tuberosum(, primarily due to the scarcity of irrigation water and the occurrence of drought stress during critical growth stages. In order to address these challenges, the utilization of aqueous superabsorbent materials and the inoculation of mycorrhizal fungi have emerged as highly suitable approaches. These methods aim to optimize the utilization of water and soil resources (Khadem et al., 2011). Previous studies have indicated that the inoculation of arbuscular mycorrhizal fungi in various plant species, apart from potatoes, can reduce the impact of drought stress and enhance nutrient uptake (Bolannazar et al., 2007; Subramanian et al., 2008). However, limited research has been conducted on the effects of superabsorbents and mycorrhizae, particularly under conditions of moisture stress and deficit irrigation in potato crops. Consequently, this experiment aims to investigate the effects of applying these methods under stress conditions.

The experiment was arranged in strip factorial based on randomized complete block design with three replications. Three irrigation levels containing optimal irrigation (100, 75 and 50% of water requirement based on evapotranspiration from Pan Class A) in horizontal plots and factor 2 using Trawat200A superadsorbent (0 and 80 kg.ha-1) and four mycorrhiza and superabsorbent levels including no application of these material (control), superabsorbent, mycorrhiza as a bio-fertilizer and their combination were considered as sub plots. The Agria potato cultivar was selected. Superabsorbent material was applied adjacent to the tubers at planting time. Mycorrhizal inoculum containing the active propagules (CFU 120 /g) was inoculated to the tubers. The concentration of nutrients in the shoot and in the tubers were determined by using Kjeldahl apparatus for Nitrogen (Waling et al., 1989), spectrophotometer for phosphorus (Jones, 2001), flame photometry for Potassium and atomic absorption spectroscopy for Iron, Zinc, and Manganese (Ryan et al., 2001). the produced tubers were divided, weighed and counted based on their size in three groups (small, medium and larg). Water use efficiency was determined as the amount of dry matter produced per cubic meter of water consumption in different treatments.

The results of combined analysis of variance showed that the main effects of irrigation rate, application of mycorrhiza and superabsorbent on tuber yield and percentage of dry matter, nutrient uptake in stem, leaf and tuber were significant. Comparison of means showed that with the application of low irrigation and increasing the intensity of water deficiency (reducing the amount of irrigation water), total yield decreased, but this decrease was significantly less in conditions of inoculation with mycorrhiza and the use of superabsorbent polymer. Mycorrhiza and superabsorbent increased the absorption of nutrients, especially under severe water deficiency. In this study, there was a significant difference in the uptake of phosphorus and other low-consumption and high-consumption nutrients at normal irrigation levels and stress in mycorrhizal plants, so that their uptake increased in proportion to the increase in stress intensity and in mycorrhizal inoculation conditions. It seems that by creating stress conditions, the ability and efficiency of mycorrhiza in nutrient uptake is increased and thus in the conditions of lack of moisture with the coexistence mechanism in the relationship of the plant more effectively helps the survival and durability of the plant. Mycorrhizal fungi can increase the uptake of phosphorus from the soil by increasing the relative water content and ultimately play an effective role in increasing plant growth (Krishna et al., 2005). In this study, it was found that the use of superabsorbent in potatoes helps to increase the absorption of nutrients. The reason for this can be increasing the storage capacity of water and nutrients for a long time in the soil, reducing nutrient leaching, rapid and optimal root growth with better nutrient storage and aeration of the soil.

In this study, it was found that the application of superabsorbent and mycorrhiza in potato helps to increase nutrient uptake as well as tuber yield. The positive effects of combined application  of mycorrhiza and superabsorbent on nutrient uptake and yield were more evident especially in conditions of severe water deficiency.
Acknowledgements
We are grateful for the efforts of Dr. Bakhtiari and Mr. Abdolreza Mordai in coordinating and equipping irrigation equipment and land preparation.

Rice (Oryza sativa L.) is one of the most important food resources of more than half of the world's population. Rice, as the second most strategic crop, is the most important cereal after wheat. Excessive use of renewable and non-renewable resources in the agricultural sector, chemical control of rice diseases, and irreparable environmental damage of these systems potentially have a variety of environmental impacts on agricultural systems, such effects can be assessed by the life cycle assessment (LCA) approach. The purpose of the present research is to assess of knowing and comparing the trend of environmental pressure of the second and ratoon cropping systems of rice production in the paddy fields.

This research was conducted in 2020 in the paddy fields of Amol city with the focus on recognizing and comparing the trend of environmental pressure in rice production in the second and ratoon cropping systems. Accordingly, all data related to the second and ratoon rice cropping systems in different stages of rice production, from planting to harvesting phases, was collected in Amol region. In this study, to classify and quantify the environmental effects of rice production in two cropping systems using the LCA method are addressed. Furthermore, the environmental impacts of these systems such as global warming potential, eutrophication, and acidification of water and soil were also calculated. In this study, the functional unit of rice production systems were considered equivalent to one ton of paddy. Therefore, in order to evaluate the emission of greenhouse gases and energy in paddy fields, the required information was collected and interviewed by paddy farmers.

The findings of this study indicated that the highest global warming potential of rice was related to the rice second cropping system about 1896.92 kg carbon dioxide per ton of produced rice. Evaluation of the LCA in rice production process showed that in the group of environmental impact of global warming, about 1673.99 kg equivalent of carbon dioxide to the atmosphere has been released per ton of rice in ratoon cropping system. Direct emissions from on-farm activities in all two studied systems have played a major role in increasing global warming. The source of these pollutants is the combustion of diesel used in agricultural implements and machinery, accompanied by the emission of nitrogen dioxide, nitrogen oxides and other nitrogenous compounds resulting from the use of nitrogen fertilizers. Also, rice second cropping systems had a greater impact on the three categories of human health damage, ecosystem quality, and climate change than ratoon cropping systems. Moreover, the values of damages on the quality of the ecosystem in these systems were about 10089.08 and 7146.58 PDF*m2 * yr in the second and ratoon cropping systems, respectively. In addition, both rice production systems have shown the greatest impact on ecosystem quality and then on human health. Direct emissions from on-farm activities in the two studied systems have played a major role in increasing global warming. The source of these pollutants is the combustion of diesel used in agricultural implements and machinery, as well as the emission of nitrogen dioxide, nitrogen oxides and other nitrogenous compounds resulting from the use of nitrogen fertilizer.

The results revealed that the rice second cropping system had the higher amount of total emissions than the ratoon cropping system, therefore, rice ratoon production system is more environmentally friendly than the rice second cropping systems.
Acknowledgements
This research was funded by the Sari Agricultural Sciences and the Natural Resources University (SANRU) under contract No. d-110-99-16690. We would also like to thank the esteemed rice farmers in Amol region, Mazandaran province, Iran for their cooperation.

Todays, efforts to increase crop yields have led to the indiscriminate use of chemical fertilizers, especially nitrogen (N) and phosphorus (P) fertilizers. It has caused soil and groundwater pollution and the destruction of soil microbial communities. Therefore, researchers should look for ways to replace N fertilizers and reduce their side effects. Intercropping of cereals and legumes due to differences in the distribution and depth of roots in the soil profile can reduce competition for water and the survival of these plants in water shortage conditions. Among the methods that may reduce the use of N and P fertilizers and thus reduce sensitivity to water stress is the intercropping of cereals and legumes. Using growth-promoting N-fixing bacteria such as Azospirillum brasilense and phosphorus solvents such as Pseudomonas fluorescens as biofertilizers can be another way to reduce the use of N and P fertilizers and the adverse effects of water stress. Therefore, the aim of this study was to investigate the effects of different fertilizer systems [chemical, integrated, and biological] on yield and competitive indices in triticale (× Triticosecale Wittmack) - chickpea (Cicer arietinum L.) intercropping under water stress conditions in Southern Iran (Fars province).

This experiment was performed as a split factorial on a randomized complete block design with three replications in the research farm of the Darab Faculty of Agriculture and Natural Resources-Shiraz University in the 2019-2020 growing season. Experimental treatments included two levels of irrigation (Ir) [Normal: irrigation based on plant water requirement (IRN) and water stress: irrigation based on plant water requirement up to the milking stage (WS)] as the main factors. The Sub-factors included three sources of fertilizer (F) [Chemical: 50 kg P.ha-1 +150 kg N.ha-1, Bio-organic: 40 tons of manure sheep ha-1 + inoculation with Pseudomonas fluorescens and Azospirillum brasillens, Integrated: 25 kg P ha-1 + 75 kg N.ha-1 + 20 tons of manure sheep ha-1 + inoculation with Pseudomonas fluorescens and Azospirillum brasilens] and three types of cropping systems (Cp) [Monoculture of triticale, monoculture of chickpea, and intercropping of triticale-chickpea (1:1)]. The crops Grain yield were measured, of the crops was measured and competitive indices including land equivalent ratio (LER), aggressivity (A), competitive ratio (CR), and system productivity index (SPI) were computed. The SAS 9.1 software was used to analyze the data, and the means were separated using the least significant difference (LSD) test at a 5% probability level.

 The results showed that the cessation of irrigation after the milking stage put severe stress on the triticale and chickpea during the grain filling period and reduced grain yield of both plants. The Ir × F interaction for triticale and chickpea grain yield showed that the lowest reduction of their grain yield (31% and 27%, respectively) were obtained in Bio treatment due to water stress as compared to IRN. Furthermore, The Ir × Cp interaction for triticale and chickpea grain yield showed that the water stress reduced their grain yield. However, the reductions were lower in intercropping system of triticale (38%) and chickpea (24%) as compared with their sole cropping. Late season water stress increased triticale, chickpea and total LER as compared with IRN conditions by 40, 65 and 51%, respectively. Furthermore, the Ir × F interaction showed that the highest and the lowest reductions (55% and 17%, respectively) of SPI were achieved in chemical and Bio treatments as a consequence of water stress conditions. 

 Based on the results obtained from this study, it can be concluded that the intercropping system of triticale and chickpea is superior to their monocropping under late season water stress conditions. Also, the lowest reduction of chickpea and triticale grain yields as a consequence of water stress was obtained by the application of Bio and integrated fertilizers. Therefore, the use of Azospirillum brasiliens and Pseudomonas fluorescens with sheep manure fertilizer not only mitigates the negative effects of water stress, but also reduces the excessive use of N-P chemical fertilizers and their harmful environmental effects and it can be an effective step for sustainability of agricultural systems.