جستجوی مقالات مرتبط با کلیدواژه « کلروفیل b » در نشریات گروه « آب و خاک »

Soil salinization is known as one of the most important reasons for soil degradation in arid and semi-arid regions, which leads to a decrease in the stability of the soil, soil fertility, and plant production, and increased dust emission. However, the use of soil microorganisms as soil inoculants improves the quantitative and qualitative components of the soil. As well as, their role in soil erosion controlling and soil management has been approved, but their success in creating biocrusts in soils with high salinity has not been considered. Therefore, this study was planned to evaluate the cyanobacteria inoculum capability for biocrust formation in the high salinity soils of the dried-up beds of Lake Urmia at laboratory conditions.

In November 2022, the soil samples were randomly taken from 10 cm above the ground in the Seporghan area, west of Lake Urmia, and transported to the laboratory of the Faculty of Natural Resources of Urmia University and kept at 4 °C. Then, the experiment trays with dimensions of 5x10x15 cm were filled with saline soil (EC= 27 dS m-1); which was taken from the dried-up beds of the west of Lake Urmia. Afterward, 225 mg of the dominant and native cyanobacteria (Nostoc sp. and Oscillatoria sp.) were identified, extracted, purified, and proliferated from the study was water-inoculated uniformly on the soil surface of each tray (or any experimental unit with an area of 0.15 m2) with three replications. On the other hand, for control treatment, the distilled water (without cyanobacteria biomass) was sprayed on the soil. After 120 days, the important indicators of the soil biocrust, such as the chlorophyll-a content, polysaccharide concentration, and activity indicators of L and a components were measured to evaluate the cyanobacteria biocrusting capability. Statistical analysis of data was done in SPSS 23 software.

The results showed that the inoculation of cyanobacteria affected the biocrust development in a high saline soil; in such a way that the cyanobacteria led to a 53.92% increase in soil chlorophyll-a compared to the control treatment. The L and a in the inoculated treatment also decreased by 21.80% and increased by 73.35%, respectively, in compared to the control, these results show the change in soil surface color to darkening and green due to the increases of cyanobacteria biomass. The L and a values confirmed the growth and activity of cyanobacteria in saline soils.

Finally, we found that cyanobacteria can grow in high-saline soils, and it is possible to propose the inoculation of cyanobacteria as a bio-based strategy. This approach is known in line with the soil conservation goals in the biocrust formation of saline soils to prevent the spread of erosion.

The study of the climatic condition of Iran shows that arid and semi-arid areas are often scattered in the central areas of Iran, and salinity in these areas is one of the limiting factors for crop production. Fenugreek is a genus of Fabaceae family and one of the important products of semi-arid regions. This medicinal plant is used in the treatment of a wide range of diseases such as diabetes. Fenugreek seeds and its leaves are rich in minerals, protein and carbohydrates. The expansion of fenugreek cultivation in the world has caused this plant to face abiotic environmental stresses during the growing season. Silica plays a role in reducing the amount of sweating and preventing the side paths of sweating. Therefore, this research was conducted with the aim of evaluating the effect of silica fertilizer in increasing salinity tolerance of fenugreek plants.

The present study was conducted in order to investigate the effect of silica fertilizer on some morphological and physiological characteristics of edible and medicinal fenugreek plant in the fall of 2022 in Behbahan city in the form of pots in the form of a completely randomized design with three replications in the open air. The treatments included salt stress at three levels (0, 75 and 150 mM sodium chloride) and silica fertilizer at two levels (0 and 3 g/l) and a total of 18 pots. Fenugreek seeds are obtained from a reputable seed store (Rahimi vegetable seed store in Behbahan city). Fenugreek seeds were planted in small plastic pots with a height of 7 cm and a diameter of 8 cm filled with garden soil, leaf soil and perlite (ratio 1:1:1) so that finally there were five plants in each pot.

The results showed that in the fenugreek plant, the maximum root length (6.95 cm) and the dry weight of the aerial parts (0.046 g) in the treatment without salt stress (control) and without the use of silica fertilizer and the lowest root length (2.63 cm) ) and the dry weight of aerial organs (0.03 g) was observed in the treatment of 150 mM salinity stress and without the use of silica fertilizer. Also, the decrease in chlorophyll fluorescence (Fv/Fm ratio) in response to salinity stress was lower than the decrease observed in salinity stress without using silica fertilizer. In the salinity stress of 150 mM and the use of silica fertilizer 3 g/liter, the amount of chlorophyll fluorescence (Fv/Fm ratio) was 0.09 more than in the treatment of salinity stress of 150 mM and no silica fertilizer. The highest value of greenness index (SPAD) was obtained in the condition without salinity stress (11.60) and the lowest value was obtained in the salinity stress of 150 mM (2.30), which was significant at the five percent level. Stress causes disturbances in the path of electron transfer and destruction of tissues related to photosynthesis, and in this way, it prevents the optimal energy consumption of the plant. In this study, silica treatment reduced the negative effects of severe salinity on root length, wet and dry weight of shoot and chlorophyll fluorescence, and reduced the harmful effects of salinity on fenugreek plants.

In this experiment, it was observed that the application of silica fertilizer in severe salinity stress significantly reduced the amount of chlorophyll fluorescence in comparison with its non-application. The present study showed that adding silicone fertilizers to saline soils reduces the negative effects of salinity stress in fenugreek plants.

In order to determine the nitrogen requirement of rice (cv. Guilaneh) using the nitrogen nutrition index and chlorophyll meter, an experiment was conducted as a randomized complete block design with three replications in the research field of the Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran in 2016. Experimental treatments consisted of six nitrogen fertilizer levels (0, 60, 120, 180, 240, and 300 kg N. ha-1; Urea source). Evaluation of the relationship between nitrogen nutrition index and chlorophyll-meter readings at three stages of plant growth (maximum tillering, booting, and heading) to predict grain yield in response to nitrogen fertilizer showed that the equation of the critical nitrogen concentration in Guilaneh was Nc = 3.99W -0.36. The correlation between chlorophyll-meter readings and nitrogen nutrition index was positive and significant at each plant growth stage. The results showed that the mature lower leaves were more sensitive than the younger higher leaves in response to nitrogen fertilizer and were more suitable for detecting plant nitrogen status, especially during the booting and heading stages. The highest correlation was found between the nitrogen nutrition index and chlorophyll-meter (r=0.95*) and relative chlorophyll-meter (the ratio of chlorophyll-meter readings in each treatment to nitrogen saturated treatment) (r=0.96**) in the third leaf and booting stage. The overall results of this experiment showed that the nitrogen nutrition index and chlorophyll meter may consider reliable indicators for evaluating the nitrogen status of rice (cv. Guilaneh) during the growing season.

With the increase of population, migration to cities and expansion of urbanization, improvement of living standards, and expansion of industries have caused a large volume of sewage to be produced in limited areas that the environment can not be refined. However, this high volume of wastewater can be considered a source of water, materials, and energy. Today, many countries make optimal use of water resources and advance their national development programs by recycling them. The use of wastewater in agriculture should not be based on a general rule. Still, it should be based on water, soil, and environment characteristics and establish a proportion between the quality of the wastewater and the type of wastewater application according to economic issues. This subject requires access to executable standards, instructions, and criteria for each of the different sections to be used to observe environmental standards. Of course, wastewater as a stable water source in irrigation of agricultural products and obedience to ecological considerations should be considered part of sound management for the water crisis.

A factorial experiment was conducted in a complete randomized design with 15 treatments and four replications in the research greenhouse of the Faculty of Agriculture, Ferdowsi University of Mashhad. For this experiment, 60 pots, 6 kg containing sandy loam soil were used. Treatments include urban water (W), treated wastewater (TWS), untreated wastewater (WS), combined urban water and treated wastewater ratio of 50:50 (W + TWS), and combined urban water and untreated wastewater (W + WS) (50:50) as irrigation water and three levels of irrigation were 100, 70 and 40% of the plant's water requirement. First, treated wastewater samples, untreated wastewater, and urban water were taken to the laboratory for water quality analysis. The seedlings were transferred to the desired pots in the three or four-leaf stage. After 150 days, the plants were harvested from the pools, and traits such as leaf number, leaf area, chlorophyll a, chlorophyll b, carotenoids, and proline were measured.

According to the analysis of variance tables, the results show that the simple effect of water quality treatment on the leaf number, leaf area, chlorophyll a and b at the level of one percent probability have a significant difference, but there was no significant difference in proline and carotenoid traits. In simple effect of deficit irrigation treatment, all measured characteristics have a considerable difference at the level of one percent probability. But, in the interaction effect of water quality and deficit irrigation, leaf number, leaf area, chlorophyll a and b, and carotenoids trait were significant at the level of one percent probability, and proline trait was not significantly different. Therefore, due to the interaction of water quality and deficit irrigation treatments, the most leaf number related to the treatment of 100% of the plant's water requirement with untreated wastewater, and the least leaf number belongs to the treatment of 40% of the plant's water requirement with urban water. In the leaf area, the most amount is related to 100% of the plant's water requirement with untreated wastewater. The least amount is related to 40% of the plant's water requirement with urban water. In chlorophyll-a trait, the most amount of chlorophyll a is associated with the treatment of 100% of the plant's water requirement with untreated wastewater. The least amount of chlorophyll is associated with 100% of the plant's water requirement with treated wastewater. In chlorophyll b, the most amount is related to the interaction treatment of 100% of the plant's water requirement, and the combination of urban water and untreated wastewater in the ratio of 50:50 and the least number is related to the treatment of 100% of the plant's water requirement with treated wastewater. Also, in the carotenoid trait, most carotenoids were related to 100% of the plant's water requirement with untreated sewage. The least amount of carotenoid was linked to 40% of the plant's water requirement with untreated wastewater.

According to the results, it can be concluded that the leaf number, leaf area, chlorophyll a, and chlorophyll b in the treatment of urban water with untreated wastewater was more than the control, and the quality of irrigation water on proline was not significantly different. Also, it is concluded that the plant's natural response to drought stress depends on the amount of water and can be short-term or long-term physiological responses. Thus, the lack of access of tomato plants to enough water reduces physiological traits such as leaf number, leaf area, and photochemical traits such as chlorophyll a, chlorophyll b, and carotenoids. But deficit irrigation increases the amount of proline, and with the drought stress intensifies, the number of proline increases. Thus, in conditions of deficit irrigation, the plant reduces its osmotic potential to absorb more water by accumulating potential osmotic regulators such as proline and soluble carbohydrates in the leaf.

In this study, the effect of water stress and nitrogen on quantitative parameters of Carla was investigated. The experiment was performed in greenhouse in a factorial manner and in a completely randomized design with three replications. Treatments included three irrigation water treatments and three levels of nitrogen fertilizer (100, 125 and 200 kg/ha, N1, N2 and N, respectively). Levels of water stress during the growing season and the weight of the pot and soil water shortage to field capacity in irrigation water by adding the amount was applied to them. Harvesting was done once a week. In each harvest, the parameters of number, weight, diameter and length of fruit and the amount of chlorophyll a and b in each pot were carefully measured. Also, yield and water use efficiency were calculated at the end of the growing season in each treatment. The results showed that the effects of irrigation water and nitrogen levels at the level of one and five percent probability on the measured parameters were significant. With decreasing irrigation water, the amount of quantitative parameters and plant yield decreased. The highest value of parameters was obtained from 100% irrigation water treatment, which was not significant in this regard with 75% irrigation water treatment. Under full irrigation conditions, the use of 100% nitrogen fertilizer increased yield and greenery indices. The highest yield was obtained in N3 treatment (full nitrogen consumption) of 15.4 tons per hectare and the highest water productivity was obtained from N3 treatment (2.12 kg / m3). Also, the interaction of nitrogen fertilizer and water stress showed that in severe water stress levels, full use of nitrogen fertilizer (N3 treatment) reduced the yield of Carla plant. Therefore, in severe water stress levels (50% irrigation water treatment), the amount of nitrogen consumption should be reduced to 75%.

Todays in agriculture, the effective use of limited soil and water resources and cultivation of new crops, resistant to environmental challenges, such as quinoa have been considered. In order to investigate the interaction effect of different levels of irrigation water and nitrogen fertilizer on yield and yield components of quinoa (cv. Titicaca), a field experiment was conducted on March 2017 during four months at Shiraz University in the Bajgah area of Fars province. A factorial experiment was conducted in a randomized complete block design with twelve treatments and three replications. Experimental Factors include: Nitrogen (N) fertilizer treatments in four levels of zero, 125, 250, 375 kg N ha-1 and the irrigation water strategies in three levels of full irrigation (FI), 75% and 50% full irrigation (0.75FI and 0.5FI. After tillage operations, quinoa seeds planted with a density of 20 plants per square meter. After plant establishment, irrigation treatments applied with basin irrigation method. Nitrogen fertilizer was given to the field in two steps of vegetation and grain filling.). Reduction Irrigation level up to 25% had no significant effect on seed yield in zero, 125 to 250 kg N ha-1 nitrogen fertilizer application levels. Increasing nitrogen fertilizer application levels from 250 to 375 kg N ha-1 under deficit irrigation (0.75FI and 0.5FI) did not make a significant difference in grain yield and the total dry matter of quinoa. Generally, the recommended irrigation regime and optimum nitrogen fertilizer application rate in the study area (Bajgah) for quinoa, based on the yield, total dry matter, harvest index, 1000-seed weight, water productivity were 0.75FI and 250 kg N ha-1 nitrogen fertilizer. Moreover, the chlorophyll index (SPAD) threshold value was 55 for the optimum nitrogen fertilizer application rate.

The application of biochar in the soil in order to improve soil quality and also waste management, has received considerable interest in recent years. Success of such management requires expert knowledge about the impact of a given biochar on soil and plant properties, before its field application. For this purpose, the effect of five different levels of biochar (0, 1, 2, 3 and 5% w/w), produced from residual of pistachio, on growth and water productivity of maize plants in a sandy and a silt loam soil was investigated. The study was performed in 2018 as a greenhouse experiment with a completely randomized design. The results showed that the effect of biochar on plant growth is strongly soil dependent. The biochar application had a negative effect on the growth of maize in the sandy soil. Root and shoot dry biomass as well water productivity were reduced more than 90% by application of 2 and 3% of biochar as compared to the control (0%), and the plant growth was hindered by further increase of biochar (at 5%). Consequently, water productivity was also reduced significantly. This negative effect of biochar application in sandy soil was attributed to an induced salinity as a result of biochar application and the low water holding capacity of the soil. In contrast, the effect of biochar on salinity of silty loam soil was not remarkable and only at application rate of 5%, it was increased significantly as compared to the control. Although the application of biochar in silty loam soil did not show a significant effect on root biomass, plant height, and chlorophyl index but shoot biomass and water productivity were increased till the application rate of 2% compared to the control. In conclusion, the results showed that i) one should be cautious with application of biochar (originated from pistachio residual) in coarse-textured soils, ii) and also the efficient application rate of each biochar should be determined in each soil before its application.

Pistachio (Pistacia vera L.) is one of the most important horticultural products and of particular economic importance. Most of pistachio orchards are irrigated with saline and low quality water which reduced production in recent years especially in the gardens of Kerman pistachio in recent years. Salinity stress is one of the important factors reducing the land ability in agricultural production and impairing the plant physiological processes and reduced growth and yield eventually. Although research on the effect of natural zeolite on some on some plant characteristics, but information about the effect of enriched zeolite as a slow release fertilizer or soil conditioner on pistachio plant under saline conditions, there are no resources. The aim of this study is to evaluate the effect of calcium enriched zeolite on some physiological characteristics of pistachio seedlings under salinity stress.
In order to investigate the response of pistachio seedlings to salinity and zeolite levels, a factorial experiment was carried out in a completely randomized design in perlite medium with three replications in the greenhouse of agriculture college, Vali-e-Asr University of Rafsangan. Treatments consisted of three levels of zeolite enriched by calcium (0, 10 and 20 % W) and four levels of NaCl (0, 75, 150 and 225 mM). 5 germinated seeds were planted in each pot at a depth of 3 cm. Hoagland solution was used for pots irrigation. Pots leaching was carried out with distilled water in the ninth week after planting and according to plan, treatments of sodium chloride (0, 75, 150 and 225 mM) was prepared as a solution added to pots in two phases and once a week. fluorescence Chlorophyll index (Fv/Fm) at 3 times (weeks twelfth, nineteenth and twenty-fourth after planting), concentration of chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, proline and protein were measured.
The results showed that, with increasing salinity the concentration of chlorophyll a, chlorophyll b and total chlorophyll decreased significantly. Application of 10 % W zeolite increased chlorophyll b by 68 percent. Salinity also decreased the fluorescence chlorophyll index and protein, so that with increasing salinity to 225 mM, fluorescence Chlorophyll index by 8 percent and protein by 37 percent decreased compared to control. Salinity increased leaf proline. Application of zeolite enriched by calcium increased mentioned parameters, so that with increasing 10 % W zeolite enriched by calcium to medium, the concentration of proline and protein, increased by 100 and 19.5 percent respectively.
In total it is concluded that the calcium-enriched zeolite (10 % W), increased the ability of pistachio seedlings in resistance to salinity stress.

Olive (Olea europaea L.) trees are mainly cultivated in the Mediterranean area and are grown for their oil or processed as table olives. Despite the fact that olive is known to be resistant to drought conditions due to its anatomical, physiological, and biochemical adaptations to drought stress, reports indicate that the olive can be adversely affected by drought stress, which has a negative effect on the growth of olive trees. In the absence of adequate supplies of water, the demand for water can be met by using improved irrigation methods or by using reclaimed water (RW). Reports have shown that recycled water has been used successfully for irrigating olive orchards with no negative effects on plant growth.Attention has been paid to reclaimed water as one of the most significant available water resources used in agriculture around large cities in arid and semi-arid regions. On the other hand, irrigation efficiency is low and does not meet the demands of farmers.In order to investigate the possibility of irrigating olive orchards with subsurface leakage irrigation (SLI) in application of reclaimed water, an experiment was carried out with the aim of investigating the effect of reclaimed water on photosynthetic indices and morphological properties of olive fruit. Research was conducted using a split-plot experimental design with two factors (irrigation system and water quality) on the campus of Isfahan University of Technology in Isfahan, Iran, on a sandy-clay soil with a pH of 7.5 and electrical conductivity (EC) of 2.48 dSm-1.PVC leaky tubes were used for the SLI system. The SLI system was installed 40 cm from the crown of each tree at a depth of 30 - 40 cm.At the end of the experiment fruit yield, weight per fruit, volume, length and firmness were calculated. A portable gas exchange system (Li-6400., LICOR, Lincoln, NE, USA) was used to measure the net rate photosynthesis (A), the internal partial pressure CO2 (Ci), and stomatal conductance (gs) between (09.30 – 11.30 h) on a fully expanded current season leaves situated at mid canopy height. Statistical assessments of differences between mean values were performed by the LSD test at P = 0.05. Results and Discussion The results revealed that reclaimed water enhanced fruit yield, weight (15%), volume (23%) and leaf photosynthesis (22%) in plants compared with clear water. Recycled water was found to supply more nutrients than clear water. High nutrient concentrations in RW, compared to those in clear water, result in nutrient accumulation in the soil, making them available to plant roots to promote overall plant growth and fruit production. Improved N, P, K nutrition of wastewater-irrigated plants has been reported (Farooq et al, 2006). Olive leaves and stems represent storage organs for N and release it in response to the metabolic demands of developing reproductive and vegetative organs (Fernandez-Escobar et al., 2004). However, Al-Abasi et al. (2009) found no statistical differences. Irrigation with SLI systems increased the photosynthesis (33%), and stomatal conductance (57%) when compared with surface irrigation systems. The results showed that reclaimed water had a significant effect on photosynthesis and stomatal conductance. However, fruit length and firmness had no significant difference. Substomatal CO2 decreased when the SI systems were used for irrigation. Also SLI system could enhance fruit yield (65%), weight (17%), photosynthesis (32%) and chlorophyll Fluorescence (Fv/Fm) (18%). The SLI systems with recycled water induced greater shoot growth, total leaf surface area, and transpiration during the entire growing period. This led to an overall positive effect on mean fruit weight and total fruit production per tree. The SLI system applying RW led to more photosynthesis by 34% as compared to the SI system. In the present study, the SLI system delivered water directly in the root zone and improved water availability, which enhanced photosynthetic assimilation rates and plant growth to a great extent. David et al. (2003) showed that subsurface drip irrigation versus other irrigation methods reduced evaporation and improved growth and production in peach trees. As a conclusion, the results from this research show that recycled water could be a promising resource for irrigation of olive trees and acted as a source of nutrients and irrigation water.In addition, SLI irrigation system is more efficient in irrigation of olive trees when compared to surface irrigation system and proved beneficial for olive growth.

To study the effect of Aquazorb super absorbent polymer (SAP) on reducing Drought stress of Acacia victoriae seedling, a split plot experiment based on the completely randomized design was conducted. In this research, stressed treatment as the main plots and amount of superabsorbent were considered as sub plot. Treatments were applied consisted of four levels of drought stress (15, 30, 60 and 100% of field capacity) and four levels of superabsorbent (0, 0.2, 0.4 and 0.6 wt%) Were studied. The results showed that survival of seedlings at the end of growth season between different treatments was the same, but the Acacia growth was responsed to the water stress and reduced growth traits were found. Using of the superabsorbent polymer had a significant effect on collar diameter, seedling height, fresh and dry root weight, relative water content of leaf and proline. According to the comparison of the means simple effects, in all of growth indices except the leaf area and root fresh weight the most means was obtained in 0.2% superabsorbent polymer treatment and also, in comparison the effect of diferent factors in most of the traits the highest means compared with 100% irrigation level without applying SAP related was to 60% irrigation level with 0.2 % SAP. That represents water savings is about 40%.

Nitrogen fertilizer application for corn (Zea mays L.) based on available N of soil can decrease the need to N fertilizer and, consequently, reduce the risk of environmental pollution, especially that of groundwater and drinking water. The objectives of this study were i) determining soil N03-N critical level at 4 to 6 leaf stage, ii) to study soil nitrate distribution, iii) determining N rate required for maximum corn grain yield, iv) measuring soil residual nitrate nitrogen after harvesting, and v) using hand chlorophyll meter to evaluate N status of corn. The experiment was conducted under field conditions in Bajgah and Kooshkak research stations (Fars Province) in 1996 using a split plot randomized complete block design with four replications. Main plots were control, 60, 120, and 180 kg N ha-1 as urea. At 4 to 6 leaf stage each main plot was divided into two sub-plots and N was applied at 60 kg N ha-1 rate to one sub-plot and the other sub-plot was left as control. Results showed that critical soil N03-N level at 4 to 6 leaf stage in 0-30 cm depth for 90 percent relative yield in Bajgah was 12-14 and for Kooshkak was 8-10 mg kg-1 soil. The highest coefficient of determination between corn grain yield and soil N03-N in 0-30 cm depth for Bajgah was in furrow sample and for Kooshkak was in furrow and shoulder composite sample. In both sites, maximum corn grain yield, with 15.5% moisture content, was about 14 mg ha-1 that was obtained through the application of 120 kg N ha-1 as preplant plus 60 kg N ha-1 as sidedress which is about 1/2 of the application rate used by local farmers. The highest residual soil N03-N after harvesting was 24 and 18 and the lowest was 2.6 and 3 mg kg-1 soil for Bajgah and Kooshkak soils, respectively. When maximum corn grain yield was obtained, chlorophyll meter reading at the middle of leaf blade at dough stage, was 49 for both sites. It seems that N fertilizer application rate by local farmers is excessive.