davood barari tari

The use of plant symbiosis with arbuscular mycorrhizal fungi (AMF) and Plant-growth-promoting rhizobacteria (PGPR) is one of the ways to reduce drought stress that has recently been used in agriculture. In the present study, the response of lemon balm (Melissa officinalis L.) plants to microbial inoculation of plant growth-promoting rhizobacteria (PGPR, Azospirillum brasilense) and arbuscular mycorrhizal fungus (AMF, Glomus mosseae) and co-inoculation (AMF+PGPR) under well-irrigated (100% field capacity) or drought stress (50% field capacity) conditions were investigated. This study was conducted in 2020 in the greenhouse of Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran as a factorial experiment based on a completely randomized design with five replications. The results of the present study showed that drought stress by reducing the relative water content (RWC, 17.8%), declined transpiration rate (E, 62.2%), stomatal conductance (gs, 36.8%), intercellular CO2 concentration (Ci, 22.5%), and net photosynthesis (Pn, 48.5%) of the plant compared to control plants. Drought stress also induced oxidative stress by increasing the accumulation of hydrogen peroxide (2.1-fold) and methylglyoxal (2-fold), resulting in damage to bio-membranes and photosynthetic apparatus and reduced growth of lemon balm. However, microbial inoculation, especially co-inoculation of PGPR and AMF, by improving the proline content and RWC, restored Ci, E, gs and Pn under drought stress. Microbial treatments by increasing the activity of antioxidant enzymes and the glyoxalase system reduced the level of hydrogen peroxide and methylglyoxal and alleviated drought stress-induced oxidative stress, which increased the growth of lemon balm under drought stress by protecting bio-membranes and photosynthetic pigments. Therefore, the results showed that the application of G. mosseae and A. brasilense alleviated the negative effects of drought stress on lemon balm.

In order to simulate yield, leaf area, and nitrogen content in rice plant by using the ORYZA2000 model under different nitrogen fertilizer amounts and various splitting approaches, a factorial experiment based on a randomized complete block design with three replications was carried out at a research farm located in the Mazandaran Province (Babol) during 2017-18.

The first factor comprised four nitrogen fertilizer rates (50, 90, 130, and 170 Kg n ha−1, supplied as urea) and the second factor comprised various fertilizer splitting appraoches (T1: 70% basal+ 30% in tillering stage; T2: 33.33% basal+ 33.33% in tillering stage+ 33.33% in panicle initiation stage; T3: 25% basal+ 50% in tillering stage+ 25% in panicle initiation stage; T4: 25% basal+ 25% in tillering stage+ 50% in panicle initiation stage).

 The results demonstrated that the model successfully simulated grain yield, biomass, grain nitrogen, and total nitrogen with RMSEn of four, four, nine, and six percent in calibration, and five, four, four, and eight percent in validation, respectively. The mean square error for the leaf area index was 0.5 and 0.4 in the model’s calibration and validation, respectively.

Based on the results obtained, the ORYZA2000 model can be used as a suitbale simulation model for selecting the best strategy for enhancing rice yield under different nitrogen fertilizer management in the rice-rich regions of northern Iran.

Lead (Pb) not only negatively alters plant growth and yield but may also have potentially toxic risks to human health. In the present study, the effects of different concentrations of Pb (150 and 300 μM) on growth, physiological and biochemical attributes of rice under hydroponic conditions were investigated. The results showed that Pb treatments with negative effects on chlorophyll metabolism reduced photosynthetic pigments and, consequently, diminished the growth and biomass of rice plants. Pb stress induced oxidative stress and damage to bio-membranes by increasing the accumulation of hydrogen peroxide and methylglyoxal. The activity of antioxidant enzymes and glyoxalase cycle was upregulated in rice leaves under Pb toxicity. Pb treatments altered the levels of non-enzymatic antioxidant compounds (glutathione (GSH) and ascorbic acid (ASA)) in the leaves of rice plants by reducing the ratios of reduced ASA to oxidized ASA and reduced GSH to oxidized GSH compared to control plants. Therefore, concentrations of 150 and 300 μM Pb in the soil can induce negative effects on important physiological and metabolic processes of rice, which reduce plant growth and biomass.

A new dimension in agricultural science has been opened up by the rapid development of computer-based information systems. Physiological processes of plant growth and development can be represented mathematically with a plant simulation model. Many studies have used simulation models to quantitatively analyze the effects of different environmental and management factors on the processes of agricultural plants due to the capability to simulate different processes. Since there is limited data on the ability of CERES-Maize to simulate maize under different nitrogen management treatments in Mazandaran, It took place in Qaemshahr city, and involved recalibration of the CERES-Maize model based on graphical representations and statistical analyses of the performance and physiological traits of this crop.

In order to simulate the physiological traits of maize using CERES-Maize model in different nitrogen treatments, an experiment was carried out in Qarakhil, a research farm of Mazandaran Agricultural Research Center, during 2017 and 2018 as randomized completely block design in four replications. The 10 treatments used in this research included: N1: not use of nitrogen (control), N2: use of 60 kg n ha-1 before planting, N3: use of 120 kg n ha-1 before planting, N4: use of 180 kg n ha-1 before planting, N5: Use of 60 kg n ha-1 in two stages (50% before planting + 50% in stage R1), N6: Use of 120 kg n ha-1 in two stages (50% before planting + 50% in R1), N7: use 180 kg n ha-1 in two stages (50% before planting + 50% in R1), N8: 60 kg n ha-1 in 3 stages (one third before planting + one third in stage R1 + one third in stage R3), N9: 120 kg n ha-1in 3 stages (one third before planting + one third in stage R1 + one third in stage R3), N10: 180 kg n ha-1in 3 stages ( One third was before planting + one third at R1 stage + one third at R3 stage).

It was shown that the model had an acceptable accuracy in simulating the yield, biomass and nitrogen level of a shoot at harvest time. It has also been shown that the trait model does not accurately simulate the leaf area index as well as other traits. According to linear regression analysis, R2 coefficients for the calibration and validation data of the model were 0.69 and 0.57, respectively,. Model validation showed a coefficient of explanation of 0.81, while calibration showed a coefficient of explanation of 0.79. Based on the two-year data, the simulated nitrogen value does not differ significantly from the measured value at 0.95 probability level. The model provided a 0.87 explanation coefficient for the difference between simulated and measured shoot nitrogen, thus indicating its accuracy in simulating total shoot nitrogen over the two-year period.

As a result of this research, the highest yield was achieved in the years 2017 and 2018 with 120 kg n ha-1 applied to the soil as 50% of the base + 50% in R1 stage. In view of the obtained results, the CERES-Maize model can be used as a suitable simulation model to find the optimal nitrogen fertilizer management strategy for maize. For generalizable results, this model can also be applied to interpreting climate data in the northern region of the country in terms of potential production, limitations, and reduction of long-term field experiments.

In order to investigate the effect of soil amendments on yield components, yield and oil percentage of rapeseed (Brassica napus L.), a field experiment was conducted as a randomized complete block design with three replications at the farmer's field located in Amol during 2021. The experimental treatments include the application of soil amendments at eight levels of control or non use of amendments, biochar, silicon nanoparticles, zinc nanoparticles, biochar + silicon nanoparticles, biochar + zinc nanoparticles, silicon nanoparticles + zinc nanoparticles, and the application of biochar + silicon nanoparticles + zinc nanoparticles. The results indicated that the application of all soil amendments improved the yield components, yield and oil content of rapeseed compared with the control treatment or non-use of amendments. In general, the combined application of amendments had better impacts on the studied traits than the individual application of each amendment. Also, among the individual treatments, the application of zinc oxide nanoparticles had the greatest effect in improving yield components and seed yield. The highest plant height (144.33 cm), number of silique per plant (240) and seed yield (3263.7 kg.ha-1) were obtained when all three amendments were used simultaneously. No statistically significant difference was observed between individual and combined treatments of amendments in terms of seed oil content. According to the results of the present study, the simultaneous use of soil amendments can have an effective role in improving the quantitative and qualitative characteristics of rapeseed.

A factorial experiment was performed as a randomized complete block design with three replications in Sari Research Farm during 2016-2017. Three levels of stress, including drought stress on the time of tillering initiation (15 days after transplanting), in remobilization stage (the end of flowering and the beginning of grain filling stage), and no drought stress (control), were considered as the main factors. Four fertilizer sources, including vermicompost, Azolla compost, humic acid, and chemical fertilizers of nitrogen, phosphorus, potassium, along with two local Tarom and Shirodi cultivars, were considered as the sub-factor. The maximum paddy seed yield was obtained in the non-stress condition using humic acid in Shirodi and local Tarom cultivars. The highest harvest index in the first year under non-stress conditions was obtained from the use of humic acid fertilizer resources in the Shirodi cultivar (54.08%), and the maximum concentrations of chlorophylls a, b, and total chlorophyll were obtained under non-stress conditions. With applying stress, especially drought stress at the complete heading stage, the chlorophyll concentration significantly reduced, so that under drought stress at the heading stage, chlorophyll a, b, and total chlorophyll concentrations reduced by 3.8, 2.6, and 3.3, respectively, compared with the control. the use of humic acid is recommended to obtain the maximum functional and physiological traits of the studied rice cultivars under drought stress.

Arsenic (As) toxicity can be a hazardous threat to sustainable agriculture and human health. In order to investigate the effect of As (0, 25 and 50 µM) on growth, physiological traits and expression of As and Fe transporters in Tarom hashemi and Fajr rice cultivars, a factorial experiment based on a completely randomized design was conducted in 2020 in greenhouse conditions at Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran. As treatments included 0, 25 and 50 μM. The results showed that As stress enhanced the uptake and accumulation of As in the roots and leaves of both rice cultivars by increasing the expression of Lsi1, Lsi2 and Lsi6 genes. As toxicity downregulated the expression of genes involved in Fe translocation to the shoot, declined the Fe accumulation in the leaves and, consequently, reduced chlorophyll content in both rice cultivars. As stress induced oxidative stress by inducing the accumulation of hydrogen peroxide and reducing the ascorbic acid and glutathione content, resulting in lessened growth in both rice cultivars. However, higher activity of antioxidant enzymes in T. hashemi reduced the level of hydrogen peroxide and malondialdehyde compared to Fajr. Higher expression of Lsi1, Lsi2, Lsi6, YSL2 and FRDL1 genes in T. hashemi caused lower As uptake and higher Fe accumulation in leaves than Fajr, which can play an important role in improving T. hashemi growth under As toxicity. Our findings showed that T. hashemi showed more tolerance to As phytotoxicity than Fajr cultivar with a more effective defense system and regulation of the expression of genes involved in the uptake and translocation of As and Fe.

Optimum use of fertilizer plays a key role in enhancing the yield of rice and other crops. The use of nano-fertilizers can be an effective strategy in optimizing fertilizer use in croping systems and achieving sustainable agriculture. This research was carried out to study the effect of nano-fertilizers spraying compared with common chemical N.P.K fertilizers use on morphological traits, yield and yield components of rice in Sari, Mazandaran province for two years (2016 and 2017). A split plot experiment, based on randomized complete block design with three replications was conducted. The main factors were two rice cultivars (Tarom and Shiroudi) and a sub plots including fertilizer treatments in 10 levels, consisting of control (without fertilizer), common fertilizers of nitrogen (N), phosphorus (P), potassium (K) and NPK, and nano-fertilizers of nitrogen (Nano-N; chelated nitrogen 17%), phosphorus (Nano-P; chelated phosphorus 17%), potassium (Nano-K; chelated potassium 27%) and NPK (Nano-NPK), plus simultaneous application of NPK and Nano-NPK (NPK+Nano-NPK). The results showed that, use of conventional fertilizers and nano-fertilizers, including the use of NPK and Nano-NPK, increased the yield and yield components of both rice cultivars. Most of the fertilizer levels (N, K, NPK fertilizers in Tarom and P, K and NPK fertilizers in Shiroudi), the use of nano-fertilizers was more affective than conventional fertilizer and increased seed yield. Application of Nano-NPK increase yield of Tarom and Shirodi cultivars by 22.54% and 12.12%, respectively as compared to the use of NPK. Since the application of chemical fertilizers is indispensable for obtaining proper yield in plants, the use of nano-fertilizers, especially Nano-NPK treatments, can be a good strategy to optimize the use of fertilizers in rice fields.

The major problem of paddy fields in Mazandaran province is the low solubility and uptake of phosphorus. This essential macro-element for plants is added to the soil as phosphorus fertilizer; but, the major part of this element is immobilized due to fixation in the soil and is unavailable for the crop plant (Zhu et al., 2011). The consequence is that farmers are turning to intensive farming and high consumption of chemical inputs (Ramezani & Hanifi, 2011). Therefore, to solve this problem, the plant growth promoting rhizobacteria (PGPB) and plant growth promoting fungi (PGPF) in the rhizosphere as well as insecure phosphate solubilizing bacteria (PSB) and phosphate solubilizing fungi (PSF) can be considered as a solution for providing consuming phosphorus for the crops (Lavakush et al., 2014). Other key solutions to solving this problem is the consumption of silicon fertilizer sources, which can be very beneficial. In fact, silicon increases phosphate uptake due to convergence with phosphorus. In addition, silicon consumption reduces plant lodging index and pests and diseases of crops (Datnoff, 2011). Therefore, this research was conducted with the aim of investigating the interaction of silicon and phosphorus fertilizer resources on the lodging indices and quantitative and qualitative parameters of rice.

The experiments was conducted as split plots based on a randomized complete blocks design (RCBD) with three replications in Amol region during 2017 and 2018. Four levels of silicon fertilizer including control (non-consumption), spray of nano-silicon, soil consumption of potassium silicate and soil consumption of calcium silicate were used as main plots and four levels of phosphorous fertilizer including control (non-consumption), chemical fertilizer (100 kg P2O5 ha-1), 50 kg P2O5 ha-1 + Herbaspirillum seropodicae bacteria inoculation and 50 kg P2O5 ha-1 + mycorrhiza fungi (Gholusmosseae) inoculation were used as sub plots. During the growth period, after the removal of marginal effect, traits were randomly measured according to the Standard Evaluation System (SES) of the International Rice Research Institute (IRRI). All statistical analysis was performed using the SAS software. A two-way analysis of variance (ANOVA) was used by GLM procedure and the least significant difference (LSD) test was used to compare the differences among treatment means at a 5% probability level.

In order to investigate the effect of silicon and phosphorous consumption on rice in the two years, firstly the data were measured by using the Bartlett method of variance homogeneity test. The results demonstrated that all the investigated traits were non-significant in the Bartlett's test, for which combined analysis of variance was performed. The lowest lodging index was obtained by spraying nano-silicon. But, the lodging index with phosphorus treatment was vs silicon usage that the highest lodging index was obtained by using chemical fertilizer + bacteria inoculation. The highest paddy yield (5147 kg ha-1) was obtained at interaction of nano-silicon spraying and using chemical fertilizer + bacteria inoculation, in this regard, chemical fertilizer treatment along with using chemical fertilizer + fungi inoculation got ranks next, respectively. Spray of nano-silicon leads to higher uptake of nutrient (Si, N, P and K) and improving qualitative and quantitative product compared to soil consumption of potassium silicate and calcium silicate, in this regards potassium silicate and calcium silicate stood ranks second and third, respectively. In addition, combined consumption of phosphorus + bacterial inoculation had higher positive effect on nutrients (Si, N, P and K) uptake than chemical phosphorous uptake along with phosphorus + fungi inoculation.

According to findings, it can be concluded that spray of nano-silicon along with consumption of chemical fertilizer + seed inoculation with bacteria can increase the quantitative and qualitative yield of rice and control the blast disease in the paddy fields.

In order to investigate the effects of chemical and organic nutritional systems on yield, water utilization in rice cultivars under irrigation stress, a split Plot factorial experiment was conducted in a randomized complete block design with three replications at Dasht-e Naz Agricultural Company, located in the city of Sari in 2016 Irrigation stress treatments were performed in three levels: the stress at the time of the beginning of the tillering (15 days after the installation of the work), the developmental stage of the transfer (the end of flowering and grain filling start) and the lack of stress (controls) as the main factor, through irrigation cut and irrigation again after the appearance of surface cracks The type of feeding system was considered in four levels of Vermicompost and compost azolla (6 and 8 t.ha-1 respectively), humic acid (4.5 L.ha-1) and the common chemical fertilizers Nitrogen, Phosphor, Potassium and cultivars were considered on two levels (Shirodi and local Tarom) in factorial form as a subagent The results variance analysis showed that there was a significant difference between Shiroudi and Tarom cultivars in terms of rice paddy yield in different levels of irrigation stress and nutritional systems. Under common irrigation conditions, the most biological functions of Paddy yield in the varieties of Shirodi and local Tarom, was obtained 6577.9 and 3776.4, Kg.ha-1, Respectively. Low irrigation stressin the developmental stage of the beginning of the tilleringreduced the rice paddy yield by 6.87 and 1.67 andin the remobilization stage, reduced the rice paddy yield by 17.65% and 2.97%, compared to non-stressed conditions With application of humic acid nutrition system, improvement of rice yield was observed in Shiroudi (6563.1 Kg.ha-1) and local Tarom (3878.77 Kg.ha-1) in compared with other nutrition systems.by using the humic acid, azolla compost and Vermicompost in Shirodi variant, the rice paddy yield increased 16.12, 9.02 and 3.62 Percent and in local Tarom 7.85, 3.47 and 2.21 percent respectively, compared with the chemical fertilizer. The highest Water Use Efficiency in the cultivars was observed with the average of 0.1050 and 0.8016 Kg/m3No rainfall, outlet runoff and tillage water were observed under conditions of non-stress. Totally, the results showed highest yield of Paddy was obtained for both Shirodi and Tarom cultivars under non-stress conditions in the humic acid nutrition system.

This experiment was conducted at Rice Research Institute of Mazandaran in 2014 & 2015 as a factorial based on randomized complete block design with three replications, the factors were nitrogen amount (40, 80, 120 and 160 kg ha-1) and splitting time application (T1: 50% basal+ 50% tillering stage); (T2: 33.33% basal + 33.33% tillering stage+ 33.33% panicle initiation stage); (T3: 25% basal+ 37.5% tillering stage+ 37.5% panicle initiation stage); (T4:25% basal + 25% in maximum tillering stage + 50% in panicle initiation). Results showed a significant effect of treatments on flag leaf all morphophysiological and evaluated traits. Also, the chlorophyll index, plant biomass, and grain yield influenced significantly by the interaction of nitrogen amount and splitting time. Most flag leaf chlorophyll index (35.9) was obtained through application of 160 kg N ha-1. Least grain yield (5490 kg ha-1) was obtained at the T1 splitting and nitrogen application of 40 kg ha-1. According to results, use of 120 kg N ha-1 with splitting time application of T3 and T4 were recommended for obtaining the best desired morphophysiological traits of flag leaf and higher yield in Shiroudi cultivar.

In order to investigate tillage system and fertilization management in improving the quantitative and qualitative traits of corn, a split-plot experiment was laid out in the base of RCBD with four replications in Darrehshahr (Ilam province) during 2016 – 2017. Experimental treatments consisted of three levels of tillage [zero-tillage (direct sowing), conservative tillage (using compound and furrower), conventional tillage (Moldboard plow + double discs + pellets furrower)] and nitrogen, phosphorus, potassium (NPK) in three levels [included not use of chemical fertilizer (NPK)0, 50% recommended NPK (NPK)50, 100% recommended NPK (NPK)100]. The results of mean comparisons showed that the highest nitrogen yield per grain (30.15 kg.kg-1) was obtained in conservative tillage which is more than the no-tillage system with the use of (NPK) 100. The highest grain yield (8401 kg.ha-1) was obtained in conservative tillage treatment with use of (NPK)100 while least grain yield (5239 kg ha-1) was obtained in no-tillage with use of (NPK)0. It can be concluded that conservative tillage improves the absorption of elements which has increased the nutrient use efficiency. Conservative tillage against no-tillage system had a positive effect on yield, yield components, and nutrient efficiency while in some traits, this increase was more than a conventional system.

Rice (Oryza sativa L.) is the staple food of more than half of the world’s population and has an important role in feeding, income and job creation in the world, especially Iran. Yield gap analysis provides little estimation of increased production capacity which is an important component in designing food-providing strategy in regional, national and global scales. The existing heated discussions regarding food security have increased the number of necessary studies that estimate the quantity of yield gap and the reasons behind it through appropriate statistical methods in Iran and the rest of the world. It seems that by defining the effectiveness of each management parameter regarding the amount of presented yield gap and, consequently, the farmer’s knowledge on that matter the distance between actual yield and attainable yield can be reduced. In this research, estimation of potential yield, yield gap, and determining yield restricting factors and each of their portions in creating rice yield gap have been investigated.

Research was done in 100 paddy fields in Amol and Rasht regions in 2016 and 2017. All managerial practices from nursery preparation to harvest for local rice cultivars were recorded through fields monitoring. Field selection was done in a way that included all main production procedures with variation in management viewpoint. To define yield model, the relationship between all measured variables and the final model was designed by controlled trial and error method, which could quantify the effect of yield limitations. The average yield was calculated by placing the observed average variables (Xs) in the fields under study in the yield model. Thereafter, by putting the best observed value of the variables in the yield model the maximum obtainable yield was calculated. The difference between these two has been considered yield gap. Different procedures of the software SAS version 9.1 were used for analysis.

Data analysis revealed that from 155 variables under study, the final model in Amol and Rasht regions with seven and six independent variables was chosen. In Amol yield model, maximum and average yield were 4798 and 6505 kg ha-1, respectively that estimated yield gap was 1707 kg ha-1. In Rasht yield model, maximum and average yield were 4443 and 6377 kg ha-1, respectively, which estimated that yield gap was 1934 kg ha-1. In Amol region, the amount of increased yield related to transplanting date, top-dressing and nitrogen after flowering variable was 364, 292 and 416 kg ha-1 which equals to 21, 17 and 24 percent of total yield increase. In Rasht region, the yield increase related to the effect of potassium and nitrogen before transplanting, and N after flowering was 644, 325 and 730 kg ha-1 which equals to 33, 17 and 38 percent.

According to the findings, we suggest that the model precision is appropriate and can be applied for both estimating the quantity of yield gap and determining the portion of each constraints yield variables. Furthermore, considering the fact that the calculated yield potential is reached through actual data in each paddy field, it is suggested that this yield potential is attainable.