نشریه پژوهشهای زراعی ایران
سال بیست و یکم شماره 4 (پیاپی 72، زمستان 1402)

Global warming directly affects agricultural production and food security (Ainsworth & Ort, 2010). Temperature controls the rate of plant metabolic processes that ultimately affect biomass production and grain yield (Hay & Walker, 1981). Although farmers are not able to control the climatic conditions, management and changes in factors such as irrigation, soil, crop varieties, activities, and technologies used in the cultivation of crops can reduce the harmful effects of climate change (Moradi et al., 2014). One of the reliable approaches to studying the effects of climate change on agricultural production is using crop growth models. The present study was conducted to simulate the effects of climate change on phonological stages and yield of maize and to investigate the possibility of mitigating the negative effects of climate change on maize by changing the sowing date and selecting suitable cultivars as management strategies for adaptation to climate change in Kermanshah region.

Materials and Methods :

The study was conducted in Kermanshah region conditions. The evaluated traits included days from the sowing date to anthesis, days from the sowing date to physiological maturity, total dry weight, and grain yield. In general, the results of the evaluations showed that the CERES-Maize model can accurately predict the growth and yield of maize cultivars (SC704, Simon, BC678) in different soil moisture conditions. After ensuring acceptable agreement between simulated values with observed values, the evaluated model was used to study the effects of climate change on maize production in the near future (2021-2050) and the far future (2051-2080) climate change according to RCP4.5 and RCP8.5 scenarios and comparing them with baseline conditions (1981–2010). The average of 17 general circulation models was used to simulate meteorological parameters under climate change conditions. The common sowing date for maize in the Kermanshah region is May 5. In this study sowing dates of May 5 and April 26 as early sowing dates, April 15 as the common sowing dates, and May 25 and June 4 as the late sowing dates, and maize cultivars SC704, BC678, and Simon were considered as adaptation strategies to climate change.

The results of simulation showed that regardless of cultivar and sowing date, traits of days from sowing date to anthesis, days from sowing date to physiological maturity, total dry weight and grain yield in the near future climate change in the scenario RCP4.5 varied as -2, -1.5, 2.7, and 3.3% and in the RCP8.5 scenario varied as, -2.9, -2.8, -0.66, and -3.6% compared to baseline conditions, respectively. These values for the RCP4.5 scenario in the far future climate change condition were -5.2, -5.4, -7.1, and -16.2 and for the RCP8.5 scenario were -8.8, -9.8, -23.1, and -45.83%, respectively. In both near and far future climate changes and under both scenarios, by sowing the studied cultivars at late dates (May 15 and May 25) compared to the early dates (April 15 and April 25) and common date (May 5), the length of the developmental period was shorter but other traits such as total dry weight and grain yield were higher. Among the studied cultivars, in both future climate changes and scenarios, the Simon cultivar had the highest grain yield. The highest duration of developmental stages and total dry weight belonged to SC704.

In general, if any of the RCP4.5 and RCP8.5 scenarios occur in the near and far future climate change periods, the sowing of the Simon cultivar should be in late dates on May 25 and will have the highest grain yield. Therefore, it can suggest as a suitable strategy to reduce the negative effects of climate change on maize production in the Kermanshah region.

Applying innovative nanotechnology in agriculture is considered as one of the promising approaches to obtain significant increases of crop yield. Nanoparticles (NPs) are considered potential agents for agriculture as fertilizers and growth enhancers and using of nano-fertilizers has led to an increasing in the efficiency of nutrients, the correct management of fertilizer consumption, and a reduction of the frequency of fertilizer application. Stimulants are compounds that initiate signals for cells to increase or decrease the production of secondary metabolites and plant defense response. Stimulants such as Putrescine play a role in regulating various plant physiological processes. In this regard, considering the importance of using new technologies, including nanotechnology, in sustainable agriculture to increase the quantitative and qualitative performance of agricultural products, especially oil-medicinal plants, and the lack of sufficient information about the use of iron nanoparticles and polyamine putricine in Camelina plant nutrition, The effect of foliar spraying of these stimulants on functional, morphological and physiological traits of Camelina plant (Soheil veriety) was evaluated.

This research was conducted as factorial layout based on a randomized complete block design with three replications at the research fields of Baye-Kala Agricultural Research Station (BARS) at Neka city in 2021. The studied factors included iron nanoparticles in four concentrations (0, 20, 40, and 60 ppm) and polyamine putrescine in four concentrations (0, 0.5, 1, and 1.5 mM). Each experimental plot was prepared in 6 square meters area and the studied treatments were applied by foliar spraying at the beginning of the reproductive phase of the plant. Two weeks after applying the treatments, sampling was done to evaluate the different traits of the plant. After checking the normality of the data, they were analyzed with SAS (ver 9.1) software; obtained averages compared with using Duncan Test at the 5% probability level.

The results of variance analysis indicated the significance of the simple effect of iron nanoparticles and putrescine on all the studied traits at the 5% level, as well as the significance of the interaction of the two factors on all the studied traits except carotenoid and peroxidase in the reproductive stage at the 5% level. According to the results, the highest amount of carotenoid (0.142 and 0.141 mg.g-1, respectively) and peroxidase (4.96 and 4.38 mg.g-1, respectively) were observed in application of 60 ppm iron nanoparticles and 1.5 mM putrescine which had no statistically significant difference with the concentration of 40 ppm iron nanoparticles and 1 mM putrescine. The results indicated that the highest amount of flavonoid (40.72 mg.g-1), soluble sugar (139.27 mg.g-1), and plant height (115.75 cm) were observed in the treatment combination of 60 ppm iron and 1 mM putrescine, the highest percentage of oil (41.76) and protein (27.77) were observed in the treatment combination of 40 ppm iron and 1.5 mM putrescine and the highest amount of grain yield (210.27 g) and morphological components of yield were observed in the treatment combination of 40 ppm iron and 1 mM putrescine. The correlation result showed that there were the most positive and significant correlation values among the physiological traits and the yield trait had a positive and significant correlation with plant dry weight (0.44) and oil percentage (0.40).

The results have demonstrated that foliar application of 40 ppm iron nanoparticles and 1.5 mM putrescine significantly enhanced various growth characteristics, including photosynthetic pigment content, crude protein, oil content, as well as the physiological and morphological aspects of Camelina. Additionally, the application of iron nanoparticles and putrescine via a uniform supply of low-consumption nutrients has been shown to strengthen the plant's defense system, ultimately leading to improvements in the growth, development, and yield of the medicinal-oil Camelina plant.

South of Iran has been located in the dry belt and desert strip thus water stress has always been one of the serious problems in its agriculture (Buzarjomehri et al., 2020). Intercropping is the cultivation of two or more plant species in a specific land and growing season, which is important in agricultural systems with limited resources and low input (Brooker et al., 2015). Due to the differences in the rooting depth, lateral expansion, and root density of cereals and legumes, they have been the best candidates for intercropping traditionally for limited soil water and nutrient availability environments (Babalola, 1980; Haynes, 1980). Application of bio-fertilizers (PGPR bacteria) that have nitrogen (N) fixation and phosphorus (P) solubilizing activity (Azospirillum brasilense and Pseudomonas fluorescence, respectively) is a promising approach for obtaining N, P, and water-restricted areas (Tien et al, 1979; Barea, 2015). Organic manures enhance soil water holding capacity and serve as excellent slow-release sources of nitrogen (N) and phosphorus (P) in the soil (Risse et al., 2006). This study aimed to investigate the effect of different fertilizer systems (chemical, integrated, and bio-organic) on triticale grain yield and its components in sole and intercropped triticale in triticale/chickpea system under late season water stress in a hot and dry area of southern Iran (Fars province - Darab).

To evaluate the yield and yield components of triticale (× Triticosecale Wittmack) in monoculture and intercropping with chickpea (Cicer arietinum L.) under late season water stress conditions, a split-factorial experiment in a randomized complete block design with three replications was implemented at the research field of the College of Agriculture and Natural Resources of Darab - Shiraz University in 2019-2020 growing season. Treatments were two levels of irrigation (Ir): [1- normal (IRN): irrigation based on the plant water requirement up to the physiological maturity stage (ZGS92) and 2- water stress (WS): irrigation based on the plant water requirement up to the milking stage] as the main plots and three fertilizer sources (FS) [1- chemical: ( 50 kg P ha-1 + 150 kg N ha-1), 2- integrated: (25 kg P ha-1 + 75 kg N ha-1 + 20 tons sheep manure ha-1 + inoculation with Pseudomonas fluorescens and Azospirillum brasilense) 3- bio-organic: 40 tons sheep manure ha-1 + inoculation with Pseudomonas fluorescens and Azospirillum brasilense] and two cropping systems (Cs) [1- monoculture of triticale, 2- intercropped triticale with chickpea (1:1)] as the sub-plots. Triticale grain yield and its components were measured and the harvest index (%) was calculated. Data were analyzed using SAS 9.1 software and the means were separated by the least significant difference (LSD) test at 5% probability level.

The results demonstrated that water stress reduced the grain yield and its components in triticale, with the extent of reduction varying among different treatments. In the Ir × Cs interaction, the Ws treatment reduced the triticale grain yield as compared to IRN by 38% and 55 % in the intercropped and sole-triticale, respectively. The Ir × Fs interaction showed that the grain yield decreased by water stress as a function of the fertilizer system (60.4%, 43.7%, and 30.7% reduction in the chemical, integrated, and bio-organic treatments, respectively). Evaluation of the results related to the triticale yield components (grain weight, biological yield, and harvest index) also showed that the Ws treatment reduced these traits. However, the least reduction occurred in bio-organic fertilizer as compared with the other fertilizer systems (significant Ir × Fs interaction). Furthermore, the Ir × Cs interaction showed that the Ws treatment reduced triticale grain weight and its biological yield as compared to IRN in both cropping systems with different manners. The least reduction of their traits by Ws treatment was showed in intercropped triticale as compared to its sole cropping.

Based on the results of this study, intercropped triticale with chickpea and using of bio-organic fertilizer were recommended for hot and dry areas of southern Iran where water stress may occur at the end of the growing seasons. Using these strategies leads to water stress alleviation and therefore less reduction of triticale grain yield in these environments.

South of Iran has been located in the dry belt and desert strip thus water stress has always been one of the serious problems in its agriculture (Buzarjomehri et al., 2020). Intercropping is the cultivation of two or more plant species in a specific land and growing season, which is important in agricultural systems with limited resources and low input (Brooker et al., 2015). Due to the differences in the rooting depth, lateral expansion, and root density of cereals and legumes, they have been the best candidates for intercropping traditionally for limited soil water and nutrient availability environments (Babalola, 1980; Haynes, 1980). Application of bio-fertilizers (PGPR bacteria) that have nitrogen (N) fixation and phosphorus (P) solubilizing activity (Azospirillum brasilense and Pseudomonas fluorescence, respectively) is a promising approach for obtaining N, P, and water-restricted areas (Tien et al, 1979; Barea, 2015). Organic manures enhance soil water holding capacity and serve as excellent slow-release sources of nitrogen (N) and phosphorus (P) in the soil (Risse et al., 2006). This study aimed to investigate the effect of different fertilizer systems (chemical, integrated, and bio-organic) on triticale grain yield and its components in sole and intercropped triticale in triticale/chickpea system under late season water stress in a hot and dry area of southern Iran (Fars province - Darab).

To evaluate the yield and yield components of triticale (× Triticosecale Wittmack) in monoculture and intercropping with chickpea (Cicer arietinum L.) under late season water stress conditions, a split-factorial experiment in a randomized complete block design with three replications was implemented at the research field of the College of Agriculture and Natural Resources of Darab - Shiraz University in 2019-2020 growing season. Treatments were two levels of irrigation (Ir): [1- normal (IRN): irrigation based on the plant water requirement up to the physiological maturity stage (ZGS92) and 2- water stress (WS): irrigation based on the plant water requirement up to the milking stage] as the main plots and three fertilizer sources (FS) [1- chemical: ( 50 kg P ha-1 + 150 kg N ha-1), 2- integrated: (25 kg P ha-1 + 75 kg N ha-1 + 20 tons sheep manure ha-1 + inoculation with Pseudomonas fluorescens and Azospirillum brasilense) 3- bio-organic: 40 tons sheep manure ha-1 + inoculation with Pseudomonas fluorescens and Azospirillum brasilense] and two cropping systems (Cs) [1- monoculture of triticale, 2- intercropped triticale with chickpea (1:1)] as the sub-plots. Triticale grain yield and its components were measured and the harvest index (%) was calculated. Data were analyzed using SAS 9.1 software and the means were separated by the least significant difference (LSD) test at 5% probability level.

The results demonstrated that water stress reduced the grain yield and its components in triticale, with the extent of reduction varying among different treatments. In the Ir × Cs interaction, the Ws treatment reduced the triticale grain yield as compared to IRN by 38% and 55 % in the intercropped and sole-triticale, respectively. The Ir × Fs interaction showed that the grain yield decreased by water stress as a function of the fertilizer system (60.4%, 43.7%, and 30.7% reduction in the chemical, integrated, and bio-organic treatments, respectively). Evaluation of the results related to the triticale yield components (grain weight, biological yield, and harvest index) also showed that the Ws treatment reduced these traits. However, the least reduction occurred in bio-organic fertilizer as compared with the other fertilizer systems (significant Ir × Fs interaction). Furthermore, the Ir × Cs interaction showed that the Ws treatment reduced triticale grain weight and its biological yield as compared to IRN in both cropping systems with different manners. The least reduction of their traits by Ws treatment was showed in intercropped triticale as compared to its sole cropping.

Based on the results of this study, intercropped triticale with chickpea and using of bio-organic fertilizer were recommended for hot and dry areas of southern Iran where water stress may occur at the end of the growing seasons. Using these strategies leads to water stress alleviation and therefore less reduction of triticale grain yield in these environments.

Seed pretreatment is one of the simple techniques that can increase seed vigor and seedling establishment, and thus plant yield. Seed pretreatment can be done with water (hydropriming), inorganic salts such as potassium nitrate (halopriming), and growth regulators such as salicylic acid (hormone priming) and ascorbic acid (vitamin priming). Another effective factor in producing strong seeds is proper nutrition of the mother plants. Proper nutrition of the maternal plant in the form of foliar sprays with essential elements leads to the production of high-quality seeds, which affects germination and yield. Considering the positive role of seed pretreatment in improving germination rate and seedling establishment, and increasing seed yield of various plants as a result of foliar application of growth regulators and inorganic salts, this experiment was conducted to study the effect of seed pretreatment and foliar spraying with salicylic acid, ascorbic acid and potassium nitrate on improving physiological and biochemical characteristics, yield and yield components of borage.

The experiment was conducted in 2017-2018 cropping year as a randomized complete block design with three replicates at Samian Ardabil Natural Resources and Medicinal Plants Research Farm. The experimental treatments were water pretreatment for 48 hours, seed pretreatment with ascorbic acid (0.85 mM) for 48 hours, seed pretreatment combined with foliar spray with ascorbic acid (0.85 mM), seed pretreatment with salicylic acid (4 mM) for 60 hours, seed pretreatment combined with foliar spray with salicylic acid (4 mM), seed pretreatment with potassium nitrate (20 mM) for 24 hours, seed pretreatment combined with foliar spray with potassium nitrate (20 mM), and control treatment (without seed pretreatment and without foliar spray of the maternal plant). Statistical analyses were performed using SAS software (Ver 9.1) and comparison of means was performed using the Duncan multiple range test at the 1 and 5 percent probability level.

The results showed that although pretreatment of seeds by improving growth, physiological and biochemical characteristics cause increased yield and yield components of borage but, seed pretreatment combined with foliar sprays had a greater effect on increasing yield components and flower and grain yield due to synergistic effects. The use of potassium nitrate as a seed pretreatment in combination with foliar sprays had the greatest effect on increasing the amount of photosynthetic pigments, caused a 2.3-fold increase in total chlorophyll and a 1.8-fold increase in carotenoids compared to the control treatment. The use of ascorbic acid as a seed pretreatment in combination with foliar sprays increased the amount of proline a 2.3 fold, leaf protein a 2.5 fold, and flower yield a 3.8 fold compared to the control treatment. Application of salicylic acid as a seed pretreatment in combination with foliar sprays by increasing the components of seed yield had the greatest effect in increasing grain yield and caused a 3.4-fold increase in grain yield compared to the control. Seed hydropriming showed the highest seed weight among the treatments with a 28% increase in 1,000-seed weight compared to the control treatment.

The results of this study indicate that both seed pretreatment and foliar sprays of maternal plants with growth regulators and chemical stimulants led to an increase in flower and grain yield in borage. This increase was achieved by enhancing the levels of photosynthetic pigments, the quantum efficiency of photosystem II, the accumulation of amino acids like proline, and soluble proteins in the leaves. These treatments also had a positive impact on various yield components. While seed pretreatment alone had a positive effect on borage yield and its components by improving the plant's growth, physiological, and biochemical characteristics, the combined use of ascorbic acid, salicylic acid, and potassium nitrate as seed pretreatment, along with foliar spray, had an even more pronounced positive effect. This was likely due to synergistic effects on the plant's physiological, biochemical, and yield traits.

The excessive use of chemical fertilizers is a leading cause of environmental pollution in the agriculture sector. Therefore, optimizing fertilizer application is a crucial approach to boost production while minimizing environmental harm. On the other hand, application of chemical fertilizers along with manure can be considered as the proper management system that led to reduce the amount of chemical fertilizers and adverse effects on environment and also improve nutrition for plants. Response-surface methodology is a powerful tool to optimize production resources which decreases cost and time of the experiments by reducing number of them. Therefore, the aim of the study was optimization of chemical fertilizers of nitrogen and phosphorus along with manure application in fodder maize production.

The field experiment was carried out according to box-benkhen design in Savojbelagh, where located in the west of Alborz province, over two years 2017 and 2018. The fifteen treatments were selected based on low and high levels of nitrogen (0 and 300 kg.ha-1), phosphorus (0 and 150 kg.ha-1), and manure (0 and 40 ton.ha-1). Three replications were considered in central points under box-benkhen design. The experiment was performed in two replications. Fodder yield, dry matter, nitrogen losses, and nitrogen use efficiency were the measured traits in the study. Stepwise regression model by fitting a full quadratic function were used to predict response variables. Treatments were optimized based on three scenarios: economic, environmental, and eco-environmental. Fodder yield, nitrogen losses, and nitrogen use efficiency were the primary factors used to determine the treatments in each respective scenario. In final, the optimum levels of treatments as independent variables were suggested to obtain target amounts of traits as dependent variables in each scenario. All analysis was performed using Minitab ver.16.

The results of regression analysis showed that the model had adequate accuracy to predict the studied properties (as dependent variables) based on experimental treatments (as independent variables). The calculated values of NRMSE illustrated that the model predicted data of dry matter, fodder yield, nitrogen losses, and nitrogen use efficiency with difference as 5.4, 2.3, 6.1, and 17.4 percent from measured data, respectively. Fodder yield was raised by increasing nitrogen fertilizer under all levels of phosphorus and manure. Increase slope of fodder yield by increasing nitrogen fertilizer amount under high levels of phosphor and manure was more than in low levels. The highest nitrogen loss was gained by application of 300 kg N.ha-1 along with no application of manure under nitrogen fertilizer × manure interaction. As findings, increasing the amount of nitrogen fertilizer caused to increase nitrogen losses and decrease in nitrogen use efficiency. Application of 242.42 kg N.ha-1 and 95.45 kg P.ha-1 along with 33.13 t manure.ha-1 was suggested under economic scenario that led to produce 105 t fodder.ha-1 with nitrogen losses of 150 kg.ha-1. In environmental scenario, no application of nitrogen and using 146.9 kg P.ha-1 with 21.82 t manure. ha-1 was proposed to gain 80.94 t fodder and 51.2 kg. ha-1 as nitrogen losses and 103.03 kg fodder.kg-1 N as nitrogen use efficiency. Under eco-environmental scenario that had priority in comparison with two other scenarios due to considering economical and environmental issues simultaneously; applying 78.79 kg N.ha-1, 150 kg P.ha-1and 8.48 t manure.ha-1 was suggested as optimum levels of treatments that led to obtain 90.87 t fodder.ha-1, 64.75 kg N losses.ha-1 and the highest value of nitrogen use efficiency as 116.4 kg fodder.ha-1 N.

Considering the results, applying 78.79 kg N.ha-1, 150 kg P.ha-1and 8.48 t manure.ha-1 in eco-environmental scenario was suggested as optimum levels of treatments.

Long-term use of chemical fertilizers can cause many adverse effects. In addition, excessive consumption of chemical fertilizers can lead to decreased food safety and low quality of vegetables, such as the accumulation of nitrates in plants. Today, using organic fertilizers is an efficient way to achieve sustainable agricultural development. The release rate of nutrients from organic fertilizers is slow and hardly exceeds the absorption capacity of plants compared to chemical fertilizers.

To compare the effect of chemical and organic fertilizers on the quantitative and qualitative traits of tomatoes in field conditions, an experiment was conducted in the cropping year of 2020-2021 in a randomized complete blocks design with three replications in the research farm of the Faculty of Agriculture, Ferdowsi University of Mashhad, Iran. Experimental treatments included: 1- biochar (8 t.ha-1), 2- animal manure (30 t.ha-1), 3- vermicompost (25 t.ha-1), 4- NPK chemical fertilizer (225 kg.ha-1 urea, 150 kg.ha-1 phosphorus fertilizer and 150 kg.ha-1 potassium sulfate), 5- 50% biochar + 50% animal manure, 6- 50% biochar + vermicompost, 7-50% animal manure + 50% vermicompost, 8- 50% biochar + 50% NPK, 9- 50% animal manure + 50% NPK, 10- 50% animal manure + 50% NPK, 11- 25% biochar + 25% animal manure + 25% vermicompost + 25% NPK and 12- control. The harvesting operation was carried out in two cutting. Five plants were randomly selected in each plot, and traits such as fruit size, length, and diameter were measured. Also, total yield, Brix index, vitamin C, and lycopene were measured in both cuttings.

In the first and second cutting, the highest fruit volume was obtained in the treatment of NPK chemical fertilizer (80.5 cm-3) and the combined use of NPK chemical + animal manure (131 cm-3), respectively. In the first cutting, the maximum fruit length was reported in the treatment of NPK chemical fertilizer (5.61 cm), and the second cutting, in the combined application of NPK chemical fertilizer + animal manure (7.16 cm) that compared to the control (4.73 cm) had a longer fruit length of 51%. The largest fruit diameter was observed in the NPK chemical fertilizer treatment (5.01 cm), which was 16% more than the control (4.31 cm). On the other hand, in the second cutting, the largest fruit diameter was shown in the combined application of chemical NPK + manure (5.54 cm). In the first cutting and the total of both cuttings, the highest yield was observed in the treatment of NPK chemical fertilizer (39.6 and 70.5 t.ha-1, respectively), while in the second cutting, the highest yield was obtained in the combined treatment of NPK chemical fertilizer + animal manure. (32.8 ton.ha-1). The results showed that using organic fertilizers individually and combinatorial compared to NPK chemical fertilizers had more Brix index, vitamin C, and lycopene. The highest amount of Brix index in first and second cutting (6.55 and 7.13, respectively), vitamin C (12.9 and 11.4 mg.100 g sample-1, respectively), and lycopene (2.48 and 2.25 mg.100 g sample-1, respectively) in the combined treatment of animal manure + vermicompost. Since the elements in the chemical fertilizer are released faster than the elements of other fertilizers and are available to the plant, therefore, by increasing the initial growth of the plant and as a result of improving its flowering potential, the total yield increased, in particular in the first cutting, where the superior treatment was the NPK chemical fertilizer. Further, due to the gradual release of organic fertilizer elements, the combined treatment of chemical and organic fertilizers increased the yield. On the other hand, organic matter plays an important role in soil fertility and performance. The rare elements in organic matter can meet the needs of soil microorganisms, enhance microbial activities, affect soil-microorganism interactions, and indirectly affect crop quality.

The use of organic fertilizer, when combined with chemical fertilizer, can enhance both the qualitative and quantitative characteristics of tomatoes. By substituting a portion of chemical fertilizer with organic fertilizer, not only can yield be improved, but it's also possible to reduce the consumption of costly chemical fertilizers. This approach aligns with sustainable agricultural goals by optimizing the use of organic fertilizers.