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IntroductionIntercropping 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. Material and MethodsA 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. Result and DiscussionThe 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. ConclusionDue 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.

IntroductionSugar beet (Beta vulgaris L.) is the second most important sugar crop after sugarcane, which annually produces about 40% of total sugar production worldwide and is adapted to different climatic conditions (El-Hag et al., 2015). Due to global warming, autumn cultivation of sugar beet is predicted to become more priority in the future, but autumn cultivation is in danger of bolting and flowering in many areas. Excessive bolting reduces sugar content, root yield, and purity of raw syrup. In general, both early sowing and delayed sowing reduce root yield, sugar, and leaf area index and increase the percentage of impurities. Therefore, this experiment was designed and implemented with the aim of feasibility study of autumn cultivation of sugar beet and determination of the best planting date in North, Razavi, and South Khorasan provinces for three new varieties resistant to sugar beet.Materials and MethodsThe experiment was conducted as a split-plot design based on a randomized complete block design with three replications in the provinces of North Khorasan (Shirvan), Khorasan Razavi (Mashhad), and South Khorasan (Khezri Dasht-e Bayaz) in 2019-2020. The main plots included three planting dates (2, 7, and 12 October) and the subplots included three bolt-resistant sugar beet cultivars (Giada, Merak, and Sharif). Each plot consisted of 6 rows with a length of 5 m, at a distance of 50 cm and a distance between two plants of 20 cm, and planting was done manually. To determine root yield from the middle rows of each plot by eliminating the margin, harvest was done at an area of 4 m2. A sample of root paste of each treatment was sent to the Beta Lizer laboratory of Mashhad Agricultural Research and Agricultural Services Company to determine the percentage of sugar. Other quality parameters were measured by Beta Lizer (Braunschweig method). Using the polarimetry method (Sucromat), the percentage of sugar content and white sugar yield, and other quality parameters were calculated for all experimental plots. Combined analysis of variance for different locations and mean comparison based on least significant difference (LSD) at the level of 5% probability using SAS 9.4 software was performed. Also, the graph plots were performed using Excel software.Results and DiscussionThe results of the analysis of variance showed that the interaction effects of the location and cultivar were significant on bolting percentage, root yield, sugar content, Na content, yield coefficient, and white sugar yield. The first planting date (October 2) in Mashhad region for all three cultivars led to the highest percentage of bolting (78-90%). Delay in planting date from 2 October to 12 October, the bolting percentage of cultivars was reduced, significantly. The bolting percentage in Shirvan region was less than 8%. On the third planting date (October 12) in all regions, cultivars showed also a bolting percentage of less than 10%. Giada cultivar in Mashhad region with 47.3 ton.ha-1 had the highest and Sharif cultivar in Shirvan region with 22.6 ton. ha-1 had the lowest root yield. Shirvan region had less root yield than the other two regions. The highest sugar content (18.78%) belonged to Giada cultivar in Shirvan region and the lowest sugar content (13.01%) was observed in Sharif cultivar in Mashhad region. The planting date of 12 October was significantly lower in impurities, alkalinity coefficient, and molasses compared to earlier planting dates. The first planting date had the lowest (62.3%) and the third planting date had the highest (74.2%) extraction coefficient. Giada cultivar in Shirvan region had the highest extraction coefficient (78.1%) and the lowest extraction coefficient (60.8%) belonged to Sharif cultivar in Mashhad region.ConclusionIn Shirvan and Khezri regions, Giada cultivar but in Mashhad region, Merak cultivars had the highest white sugar yield. In general, the results showed that in Shirvan region, planting on 2 October and in Mashhad and Khezri regions planting on 7 October could lead to reaching maximum white sugar yield.

Introduction[1]Intercropping is a well-known agro-ecological practice for its dramatic effect on pest and weed control, increasing productivity as well as enhancing resources (radiation, water and nitrogen) use efficiency. All these beneficial effects are the results of increased species diversity which presumably would be higher with introducing more component species. On the other hand, crop growth analysis provides indices for quantifying the rate of dry matter production and allocation of dry matter to the other organs, particularly to leaves. It seems that growth indices of intercropped species relative to their pure stands could be useful for better understanding of higher productivity of more diverse intercrops.The objective of this study was comparison of growth indices and dry matter allocation as well as land equivalent ratio of fennel (Foeniculum vulgar), common bean (Phaseolus vulgaris) and sesame (Sesamum indicum) grown in monoculture or intercropping systems. Materials and MethodsThe experiment was conducted as randomized complete block design with three replications and seven treatments including pure fennel (F), pure sesame (S), pure bean (B), row intercropping with 1:1 ratio of FB, SB and FS as well as 1:1:1 intercrop of FSB. All treatments were sown in recommended planting date and density. Total aboveground materials of each plot were sampled in 5 randomly selected plants in two-weekly intervals and repeated seven times during growth period. Green leaf area index (GAI) and total aboveground dry matter (DM) were measured for each species in sole and intercropped plots. Time course of LAI and DM was estimated by fitting logistic peak and sigmoid functions to the measured values for each species, respectively. Crop growth rate (CGR; g m-2 d-1) of each species was estimated as the first derivative of the sigmoid function. Economic yield of species was measured by harvesting the whole plots and used for calculation of land equivalent ratio (LER) for intercropping treatments. Results and DiscussionResults showed that for all studied species, the growth indices were lower in intercropping compared to monoculture. Maximum GAI (1.28), dry matter (184.6 g.m2) and crop growth rate (5.2 g.m-2.day-1) for fennel was observed in pure stand. For sesame, the highest GAI (4.2) was obtained in the sesame – fennel intercrop, however, maximum dry matter (1023 g.m-2) and crop growth rate (24.5 g.m-2.day-1) were achieved in the pure stand of sesame. Similarly in bean, maximum GAI (3.8), dry matter (546.39 g m-2) and crop growth rate were observed in pure stand. However, the lowest GAI (0.61), dry matter (54 g m-2) and crop growth rate (1.6 g m-2 day-1) of fennel was observed in fennel-sesame and fennel-sesame–bean intercrops, respectively. The minimum GAI (3.24), dry matter (286 g.m-2) and crop growth rate (6.6 g.m-2.day-1) of sesame was obtained in fennel- sesame- bean, fennel- sesame and fennel- sesame- bean, respectively. The minimum LAI (3.08), dry matter (110 g.m-2) and crop growth rate (3.26 g m-2day-1) of sesame was observed in fennel- sesame- bean treatment. Despite the lower growth indices, LER was grater that 1 in all intercrops with a highest value (1.09) in sesame – bean showing the better allocation of dry matter between component species of intercropping. ConclusionWhile the LAI, DM and CGR was lower when species were intercropped, the overall rate of dry matter production of intercropping systems was about 28%, on average, higher as compared with pure stands leading to almost 10% higher productivity. Addition of the third species into intercrops has no significant effect on productivity. However, it seems that using species with diverse functional traits to increase functional diversity could cause higher productivity of intercropping systems.

Introduction: One of the most important factors that play a major role in reducing soil fertility and agricultural land degradation is soil salinization. Soil salinity problem is more severe in agricultural lands of arid and semiarid regions. In many cases, human activities and irrigation of agricultural lands with saline water are the cause of salinization. This is a serious problem in different regions of Iran, especially in Khuzestan Province. Therefore, the present study was conducted with the aim of monitoring and evaluating the effect of Gotvand Dam on the salinization of the downstream area and changing its plant ecosystem before and after water intake using remote sensing imagery. Material and methods: The time series of two ETM+ and OLI sensors from 2019-1999 were collected using plant indices (NDVI, SAVI), biophysical index of leaf cover (LAI), and salinity indices. The soil was classified by salient decision-making method of changes in halophyte and non-halophyte plants according to the threshold obtained from the indicators used in each year. Then, the final results were evaluated according to the trend of changes obtained from the used indicators and their correlation with changes in the plant ecosystem of the region. Results and discussion: The rate of vegetation changes in the four years of 2018, 2013, 2002, and 1999 was more than other years, which was prepared by the method of supervised classification of the area under normal vegetation and saline plants. According to the results obtained from 1999, the total vegetation area of the groves was about 1117 hectares, of which about 134 hectares were related to halophyte vegetation. However in 2018, these values were estimated at 921 hectares, with areas covered by halophyte changing to 445 hectares and halophyte to 476 hectares. Conclusion: The results of the study indicate the onset of the highest stresses in the plant ecosystem of the region and the simultaneous decline in leaf cover and NDVI with the water intake of Gotvand Dam since 2011. This coincidence, which is due to the salinity of the water of Gotvand Dam Lake and consequently Karun River, has a significant effect on increasing salinity and changes in soil quality of the region and thus increasing halophyte plants as well as high vegetation degradation in the region. These conditions can create more serious challenges for the ecosystem of this area and in the long period change the ecosystem and vegetation cover of this region to halophyte plants. [ABSTRACT FROM AUTHOR]

Introduction: One of the most important factors that play a major role in reducing soil fertility and agricultural land degradation is soil salinization. Soil salinity problem is more severe in agricultural lands of arid and semiarid regions. In many cases, human activities and irrigation of agricultural lands with saline water are the cause of salinization. This is a serious problem in different regions of Iran, especially in Khuzestan Province. Therefore, the present study was conducted with the aim of monitoring and evaluating the effect of Gotvand Dam on the salinization of the downstream area and changing its plant ecosystem before and after water intake using remote sensing imagery. Material and methods: The time series of two ETM+ and OLI sensors from 2019-1999 were collected using plant indices (NDVI, SAVI), biophysical index of leaf cover (LAI), and salinity indices. The soil was classified by salient decision-making method of changes in halophyte and non-halophyte plants according to the threshold obtained from the indicators used in each year. Then, the final results were evaluated according to the trend of changes obtained from the used indicators and their correlation with changes in the plant ecosystem of the region. Results and discussion: The rate of vegetation changes in the four years of 2018, 2013, 2002, and 1999 was more than other years, which was prepared by the method of supervised classification of the area under normal vegetation and saline plants. According to the results obtained from 1999, the total vegetation area of the groves was about 1117 hectares, of which about 134 hectares were related to halophyte vegetation. However in 2018, these values were estimated at 921 hectares, with areas covered by halophyte changing to 445 hectares and halophyte to 476 hectares. Conclusion: The results of the study indicate the onset of the highest stresses in the plant ecosystem of the region and the simultaneous decline in leaf cover and NDVI with the water intake of Gotvand Dam since 2011. This coincidence, which is due to the salinity of the water of Gotvand Dam Lake and consequently Karun River, has a significant effect on increasing salinity and changes in soil quality of the region and thus increasing halophyte plants as well as high vegetation degradation in the region. These conditions can create more serious challenges for the ecosystem of this area and in the long period change the ecosystem and vegetation cover of this region to halophyte plants. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effects of water deficit stress, nitrogen fertilizer and zeolite on growth parameters, biomass and seed yield of fenugreek. A split factorial experiment based on a randomized complete block design with three replications was conducted at the Research Field of Tarbiat Modares University in 2014 and 2015. Five irrigation regimes (unstressed, mild stresses during the vegetative and reproductive stages, respectively; severe stresses during the vegetative and reproductive stages, respectively) were randomized to the main plots. Subplots consisted of six treatments of a factorial combination of three levels of nitrogen fertilizations (untreated plots, vermicompost fertilizer at a rate of 2.7 t.ha-1 and nitrogen chemical fertilizer at a rate of 11 kg.ha-1) and two rates of zeolite (0 and 9 t.ha-1). In both years, increasing severity of water deficiet stresses reduced leaf area index, crop growth rate, plant height, biological and seed yield of fenugreek; Thus, severe water deficit stress at the reproductive stage without fertilizer and zeolite (with the least amount of biological and grain yield) compared with that of control, caused 60.96 and 48.09 percent reduction in biological yield and 80.18 and 75.62 percent reduction in grain yield, in both years, respectively. Application of nitrogen fertilizer, especially vermicompost, resulted in a significant increase in the leaf area index, crop growth rate of fenugreek in various stages of development, thereby increased biological and grain yield in different irrigation regimes. In various irrigation regimes, higher leaf area index, crop growth rate and finally more yield produced with application of vermicompost or zeolite.

مقدمه و هدف دانه حبوبات با برخورداری از درصد پروتئین بالا، مکمل کیفی دانه غلات می­باشد. درمیان تنش­ های محیطی، کمبود آب مهم­ترین عاملی است که باعث محدودیت کاشت و کاهش عملکرد محصولات غذایی می­گردد. کودهای آلی علاوه بر نقش تغذیه­ ای، در بهبود خواص فیزیکی و بیولوژیک خاک مؤثر هستند. با توجه به پیامدهای مثبت مصرف مایه­ های تلقیح ریزوبیومی ازجمله، افزایش کمیت و کیفیت محصول، بهبود شاخص‌های رشد، کاهش غلظت نیترات در محصولات کشاورزی و آب­های زیرزمینی و حفظ محیط‌زیست،این پژوهش به‌منظور بررسی اثرات تلقیح باکتری و کود گاوی بر برخی خصوصیات نخود رقم هاشم تحت شرایط تنش خشکی و ترویج مصرف کودهای سازگار با محیط‌زیست طراحی و اجرا شد. مواد و روش‌ها آزمایش در سال زراعی 1392- 1391 در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه شهرکرد به‌صورت اسپیلیت پلات فاکتوریل در قالب طرح بلوک­های کامل تصادفی در 3 تکرار انجام شد. فاکتور اصلی شامل سطوح مختلف تنش خشکی در سه سطح (80، 100 و 120 میلی‌متر تبخیر از تشتک تبخیر کلاس A) و فاکتور فرعی، شامل کود گاوی در سه سطح 0، 50 و 100 درصد نیاز کامل گیاه (20 تن در هکتار) و تلقیح باکتریایی بذور (Mesorhizobium) در دو سطح (تلقیح و عدم تلقیح) بود که به‌صورت فاکتوریل در کرت­های فرعی قرار گرفت. به‌منظور تعیین زمان آبیاری، میزان تبخیر روزانه از تشتک تبخیر هر روز عصر اندازه­گیری شد و پس از رسیدن به حد موردنظر، آبیاری به روش سیفونی صورت گرفت. یافته‌ ها نتایج نشان داد که با افزایش شدت تنش خشکی از میزان سرعت رشد محصول و شاخص سطح برگ کاسته شد. سرعت رشد محصول و شاخص سطح برگ در تیمار تلقیح باکتری به‌طور معنی­داری نسبت به عدم تلقیح افزایش یافت. مقایسه میانگین‌ها نشان داد که با افزایش شدت تنش، تمامی اجزاء عملکرد کاهش معنی­داری داشتند اما درصد پروتئین دانه افزایش پیدا کرد. افزایش مصرف کود گاوی و تلقیح باکتری باعث افزایش اجزاء عملکرد دانه و درصد پروتئین آن شد. مقایسه میانگین اثرات دوگانه تنش خشکی × تلقیح باکتری نشان داد تلقیح باکتریایی سبب افزایش معنی­دار تعداد غلاف در بوته در تمامی سطوح تنش خشکی گردید. مقایسه میانگین اثرات دوگانه کود گاوی × تلقیح باکتری نشان داد که تلقیح باعث افزایش تعداد غلاف در بوته در تمامی سطوح کود گاوی گردید. بیشترین وزن صد دانه در تیمار 20 تن کود گاوی در هکتار و تلقیح باکتری به دست آمد. نتایج اثرات متقابل سه‌گانه نشان دادبیشترین وزن صد دانه در تیمار شاهد ×20 تن کود گاوی در هکتار × تلقیح باکتری به دست آمد. با افزایش شدت تنش خشکی عملکرد دانه و عملکرد بیولوژیک به‌طور معنی­داری کاهش یافت. بیشترین و کمترین عملکرد دانه و عملکرد بیولوژیک براثر مصرف کود گاوی به ترتیب در تیمارهای 20 تن کود گاوی در هکتار و عدم استفاده از کود گاوی بود. تلقیح باکتریایی باعث افزایش معنی­دار عملکرد دانه و عملکرد بیولوژیک گردید. نتایج مقایسه میانگین اثرات دوگانه کود گاوی × تلقیح باکتری بر عملکرد دانه، عملکرد بیولوژیک و شاخص برداشت نشان داد که بیشترین میانگین عملکرد دانه و عملکرد بیولوژیک در تیمار عدم استفاده از کود گاوی × تلقیح باکتری به دست آمد. نتایج مقایسه میانگین اثرات سه‌گانه بر عملکرد دانه نشان داد که بیشترین عملکرد دانه در تیمار تلقیح باکتری × عدم استفاده از کود گاوی × شاهد به دست آمد. نتیجه‌گیری به‌طورکلی در این پژوهش می­توان بیان کرد که تیمارهای تنش خشکی و تلقیح باکتری تأثیر بیشتری بر شاخص­های فیزیولوژیک، عملکرد و اجزای عملکرد دانه نخود می­گذارند. تنش خشکی موجب کاهش منابع فتوسنتزی و محدودیت آسیمیلات­ها می­گردد و بنابراین منجر به کاهش وزن صد دانه و کاهش سطح برگ و درنتیجه کاهش سرعت رشد محصول می­شود. در این آزمایش مشخص شد که کاربرد باکتری در شرایط تنش خشکی موجب تعدیل اثرات تنش می­گردد بنابراین پیشنهاد می­گردد که در مناطقی که احتمال وقوع تنش خشکی وجود دارد، از تلقیح بذور استفاده گردد.

In order to investigate the effect of water deficit on yield and morphological characteristics of four alfalfa cultivars an experiment was conducted as a split plot in randomized complete block design with 3 replications in Agriculture Research Center of Khuzestan, Ahwaz, Iran, during 201l-2012. Main plots included irrigation regimes (normal irrigation, irrigation at 50% available water content (AWC) depletion, 65% AWC depletion and 80% AWC depletion) and subplots were 4 cultivars of alfalfa (Baghdadi, Mesasirsa, Yazdi and Hamedani). The result of 5 cuttings showed that maximum hay forage yield was achieved under normal irrigation in all cultivars. The Baghdadi cultivar produced the highest hay yield at all irrigation treatments, though the hay yield decreased with delay in irrigation. The leaf/stem ratio increased by 22 percent when the cultivars where subjected to 50% AWC depletion. Stem height, LAI and the weight of single stem were decreased by delay in irrigation. Specific leaf area (SLA) decreased in all cultivars due to water deficit, though the extent of the decrease was greater for Baghdadi cultivar. The water deficit affected stem number in a cultivar-specific manner as it increased in Baghdadi and Mesasirsa cultivars and decreased in other cultivars. The Baghdadi and Mesasirsa appeared to be the most tolerant cultivars in Khuzestan conditions.