جستجوی مقالات مرتبط با کلیدواژه "سولفات پتاسیم" در نشریات گروه "کشاورزی"

In producing medicinal plants, it is critical to use plants with a high percentage of active ingredients and consume low amounts of water. Thymus daenensis Celak is a tolerant Thymus species for rainfed cultivation. In addition, using complementary irrigation regimes and applying anti-stress compounds at critical stages of plant growth are suitable programs for sustainable production and optimal water consumption under dry farming conditions. For this purpose, this experiment was to evaluate the effect of different complementary irrigation regimes along with sodium nitroprusside (SNP) as a nitric oxide donor, kaolin, and potassium spraying on yield and some biochemical characteristics of T. daenensis under rainfed conditions. This experiment was designed and implemented as a split plot based on a randomized complete blocks design with three replications in the research field of the Research Institute of Forests and Rangelands-Homand Rangelands Research Station (Damavand) for three years (2017-2019 crop years). The experimental treatments included complementary irrigation as the main factor at three levels: control (no irrigation), one and two complementary irrigation, and spraying of stress-modulating substances as a secondary factor with three compounds of SNP (200 µM), kaolin (5%) and potassium (75 kg/ha from a potassium sulfate source). Cultivation was indirect and through seedlings. To prepare seedlings, the seeds were planted in the cultivation trays in the greenhouse at the end of September. After growing in the greenhouse, the seedlings (8-10 leaves) were transferred to the field in November with rain monitoring. Complementary irrigation and different foliar spraying treatments were done twice in the pre-flowering and 10 % flowering stages. Treatments were applied in the third year of plant growth to increase economic yield. After applying the treatments, the plant's flowering branch was sampled to measure malondialdehyde (MDA). After measuring the morphological characteristics (plant height and canopy diameter) in the full flowering stage, plant shoots were harvested to determine the dry matter yield per square meter and hectare. Percentage and yield of essential oil, total phenol, total flavonoids, and antioxidant capacity were also determined. The results showed that increasing the number of complementary irrigations increased the crown diameter, plant height, and dry matter yield per plant and hectare. Kaolin treatment under two complementary irrigation regimes had the highest height (31.6 cm), and the control treatment under no irrigation had the lowest height (19.3 cm). Also, using kaolin and two complementary irrigations showed the highest dry matter yield per m2 (77.2 grams) and per hectare (771.4 kg). In addition, MDA content was lower in the double complementary irrigation treatment with kaolin foliar spraying (1.22 μmol/g of fresh weight). Foliar spraying of kaolin, potassium, and SNP under rainfed conditions (without irrigation) increased the amount of essential oil (by 1.83, 1.67, and 1.6 percent, respectively) compared to the control treatment (1.4 percent). In contrast, the maximum essential oil yield per hectare was related to the double complementary irrigation regime with potassium foliar spraying (10.6 kg/ha). Foliar spraying with potassium in the regimes of without irrigation (rainfed) and one-time complementary irrigation had the highest content of total phenols and flavonoids, respectively. The highest antioxidant capacity was obtained without irrigation and foliar spraying (control). This experiment showed that complementary irrigation increased dry matter yield per plant and hectare. On the other hand, foliar spraying with anti-stress compounds, especially kaolin, and potassium, along with complementary irrigation, increased essential oil yield per hectare. In general, based on the results of this experiment, it is suggested to use complementary irrigation regimes according to the available water sources. In addition, it is suggested to use kaolin or potassium foliar application under rainfed conditions for T. daenensis.

Food security is one of the basic needs of any society. Studies have been conducted on the foliar application of elements, especially silicon, calcium, and potassium, to reduce the adverse environmental effects on the physico-mechanical properties of cereals and improve their growth and development in order to maintain food security. Lodging, which is caused by a decrease in the mechanical properties of the plant stem's flexural strength, is characterized by bending or fracture that changes the angle of the grain stem from the vertical position. Due to the important factors involved, an important aspect of performance is directly and indirectly related to the occurrence of fungal diseases and nutrient-related issues affecting the physico-mechanical properties of the plant, such as flexural strength. The efficacy of silicon, calcium, and potassium in addressing these concerns is notable.

This research was conducted at the research farm of the Faculty of Agriculture, Shahroud University of Technology, located in Bastam. The seeds of the Reyhan cultivar, a high-yielding and early spring-type barley plant suitable for regions with mild winters and short springs, were used in this study. Planting operations followed agricultural principles, and irrigation was carried out using atmospheric and ridge methods. The first irrigation took place after planting, and subsequent irrigations were performed aeight-day intervals. Harvesting was done manually at the end of the growing period, specifically 115 days after planting.The experiment followed a factorial design and utilized a randomized complete block design with three replications. On July 11 (115 days after planting), a harvest sample measuring 50 cm2 was taken from each experimental plot, accounting for the margins, to determine the yield.For the barley stem bending test, a three-point bending test was conducted using a material testing machine. The probe applied a loading speed of 5 mm.min-1. A specially designed jaw was used for the barley stem cutting test, taking into consideration the characteristics of the barley plant. The incision test was performed on the second median, and the loading speed was set at 20 mm.min-1.

The main axial stem serves as a storage organ, supporting the filling grains through stock re-transference. A desirable trait is having a higher dry weight in the stem. Among the treatments, foliar application of 6 mM calcium chloride, along with sodium silicate at all three levels and spraying with 12 mM silicon at concentrations of 150 and 300 mg.L-1, showed statistically superior results.Stem diameter is an important attribute related to plant strength, stability, resistance to lodging, and certain fungal diseases. The control plants had a stem diameter of 2.63 mm, which significantly improved with the treatment compounds. Barley stem wall thickness increased significantly with both 150 and 300 mg.L-1 levels of calcium chloride, combined with all three levels of sodium silicate spraying. These factors play a role in determining the ultimate photosynthetic destination, as well as the efficiency and economic production of the target seed cultivar or crop.The results indicated a significant increase in grain yield when simultaneously applying 10 mg.kg-1 silicon with 6 mM calcium chloride, showing a 65% improvement compared to the control. Treatment with three potassium sulfate variations, combined with either 6 or 12 mM calcium chloride, or 12 mM calcium chloride alone, enhanced the flexural strength of the stem by 75%, 60%, and 62%, respectively. Among the treatment compounds studied, the shear strength of barley stems ranged from 2.63 MPa to 5.43 MPa. Plants treated with sodium silicate at concentrations of both 150 and 30 ml.L-1, in conjunction with 6 mM calcium chloride foliar application, exhibited higher shear strength compared to other treatments.

This study demonstrated the tripartite effect of the treatments. The treatment composition derived from a surface area of 300 ml.L-1 of sodium, combined with 6 and 12 mM calcium chloride without potassium sulfate, had the greatest impact on flexural strength and stem diameter.

 Drought is the most important limiting factor for the yield and quality of products in the world. Fertilizer application can mitigate drought stress in plants. Most farmers prefer to use inorganic (chemical) fertilizers because of their fast impact on plant growth. The reasonable cost of inorganic fertilizers and their availability are the other reasons. However, the long-term effects of organic fertilizers on plant growth and soil fertility has been proved. The grapevines are one of the most important garden products in the world as well as in Iran. It has been reported that the application of biochar has significant effects on soil fertility as well as plant growth. Biochars have properties such as highly porous structure, high specific surface area, higher water holding capacity of the soil, the long-term stability in the soil. In addition, our previous study indicated that it could decrease the hazard of sodium in soil compared with compost. In Iran, the cultivation area of grapevines was the second grade after the pistachio cultivation area in 2019. According to statistical data on agriculture in 2019, the cultivation area of irrigated and rain-fed grapevines in Kermanshah province was 7710 and 1515 ha, respectively. According to this report, the production of irrigated and rain-fed grapevines in Kermanshah province in 2019 was 82718 and 1763 tons, respectively. The effect of application of some inorganic and organic fertilizers under drought stress on yield, water use efficiency, and some biochemical characteristics of the grapevine leaves cultivar Bidane-Ghermez has been previously studied. In this research, the effect of drought stress and the application of potassium sulfate, compost, and biochar on antioxidant activities of the grapevine leaves cultivar Bidane-Ghermez was investigated.
 
A greenhouse study with a factorial experiment based on a block of randomized completely design was conducted with fertilizer treatments including control, potassium sulfate (1250 mg kg-1), compost (5% w/w), and biochar (10% w/w) without and with drought stress conditions (80 and 40% FC, respectively) during 2017-2018. For this research, the biochar was produced from apple tree pruning under low oxygen conditions by slow pyrolysis at 400 ◦C. The compost was purchased from the municipal compost factory of Kermanshah province. To evaluate drought stress and inorganic and organic fertilizers' application on antioxidant enzymes activities, the superoxide dismutase and peroxidase activities and total soluble protein of grapevine leaves were determined. The data were analyzed by ANOVA and the mean of studied characteristics was compared by Duncan’s test at 5% probability level using SAS software.
the results indicated that the interaction effect of fertilizers treatments and drought stress on the superoxide dismutase and peroxidase activities as well as total soluble protein was significant (P<0.01). Under drought stress conditions, among fertilizers’ treatments, the activity of superoxide dismutase for potassium sulfate was significantly lower than compost and biochar treatments (P<0.01). The results also showed that the peroxidase activity for compost was significantly higher than potassium sulfate and biochar treatments (P<0.01). Besides, the highest total soluble protein amount was found for biochar treatment (P<0.01).
 
 according to the results of this study, it can be concluded that the increase of total soluble protein of grapevine leaves under drought stress conditions by biochar application contributed to the increase of superoxide dismutase and peroxidase activities also increasing the bioavailability of macro-and micronutrients. Biochar application increased significantly the potassium concentration of the leaves of the grapevines. Potassium regulates water movement at the plant and also provides a higher relative water content of grapevine leaves. Moreover, potassium decreases the non-stomatal effects are also attributed to stomatal closure during drought stress conditions. Furthermore, potassium contributes to protein synthesis. Biochar application also increased the phosphorus, copper, and magnesium of the leaves of the grapevine. Higher concentration of phosphorus under drought stress conditions caused the grapevine leaves to suffer less from phosphorus deficiency. Copper exists in superoxide dismutase and is considered a key player in superoxide detoxification. Under drought stress conditions, higher manganese concentration by biochar application resulted in more protection of the cellular membrane against Reactive Oxygen Species (ROS). For fertilizer recommendation in order to reduce drought stress effects on some antioxidant enzymes activities of Bidane-Ghermez grapevine leaves, the application of biochar is recommended first then potassium sulfate and compost.

Crop residue management is one of the main pillars of production in agriculture and in the long run plays an important role in increasing or decreasing crop yields. Adequate amount of potassium sulfate fertilizer in the soil modulates the osmotic pressure in the soil. in this way, the plant's ability to withstand drought increases. Due to the fact that sour tea is one of the most important medicinal plants in Sistan, so it needs more study and research. Therefore, this experiment was conducted to investigate the effect of tillage systems combined with crop residue management and application of potassium fertilizer on yield and some physiological characteristics of sour tea in Sistan climate.

In order to investigate the effect of tillage systems with crop residue management and application of potassium fertilizer on yield and some physiological characteristics of sour tea, an experiment was conducted in the research farm of zabol university agricultural research institute in 2018-2019 as a split plot-factorial in the form of complete block design. randomization was performed in three replications. experimental factors including tillage systems at three levels without tillage, reduction tillage (disc) and conventional tillage (plow + disc) as the main factor and the combination of plant residues at three levels (zero, 30 and 60%) with potassium sulfate fertilizer at three levels (no fertilizer, 75 and 150 kg  ha-1) were considered as secondary factors. measurements were: economic yield, biological yield, harvest index, chlorophyll a, b and carotenoids, anthocyanins, flavonoids and protein.  statistical analysis of data was done with SAS software version 9.1 and mean comparison with duncan test was conducted at 5%.

The results showed that the use of tillage systems and their interaction on the studied characteristics were significant, However, plant residue treatments and their interaction on the studied characteristics except harvest index and anthocyanin were significant, Potassium sulfate treatment and its interaction on the studied properties except harvest index and flavonoids were significant. The highest economic yield of sour tea was equal to 3221.7 kg  ha-1 in the reduced tillage system with 60% of crop residues and 150 kg  ha-1 of potassium sulfate and The highest amount of sepal anthocyanin was obtained from conventional tillage treatment and combined use of 30% residues and 75 kg  ha-1 of potassium sulfate and Conventional tillage and combined use of 30% residues and 75 kg  ha-1 of potassium sulfate increased chlorophyll a, b and carotenoids. Also, non-tillage and conventional tillage treatments increased the amount of flavonoids and protein at the branches. The results of comparing the means of interaction of tillage systems with crop residue management and application of potassium sulfate show that the highest increase in chlorophyll a and carotenoid content of conventional tillage is + 30% of crop residues and 75 kg  ha-1 of potassium sulfate And the highest increase in chlorophyll b was the simultaneous use of conventional tillage + 60% of crop residues and 150 kg  ha-1 of potassium sulfate. the highest amount of protein was related to conventional tillage treatment with zero percent of crop residues and potassium sulfate, the results of comparing the means on the interaction of the treatments showed that the simultaneous application of no-till treatment with zero percent of crop residues and potassium had the best effect on the amount of flavonoids.

The results indicate that the effect of tillage systems combined with crop residue management and application of potassium sulfate in increasing quantitative and qualitative characteristics has had the best results. Under conservation tillage, by reducing tillage operations and maintaining a sufficient amount of plant residues in the soil surface, while improving soil structure and increasing water efficiency and nutrient efficiency, that increased quantitative and qualitative characteristics. Despite the dry climate in the country and the limitations and shortages of water and reducing soil fertility on the one hand and increasing environmental pollution on the other hand, the need to use conservation agricultural systems to maintain yield and stability and ultimately stability and balance of environmental factors is necessary it seems.

Potassium is the most abundant inorganic cation in plant tissues that plays a major role in physiological processes, especially in growth and metabolism. Although there is substantial evidence about the effects of potassium fertilizer on increasing the qualitative and quantitative yield of plants, little is known about the effects of applied potassium on saffron and the improvement of the quality and yield of the saffron flower. The purpose of this study was to evaluate the effects of biological and chemical potassium fertilizer and corm weight on some physiological traits and yield of saffron (Crocus sativus L.).  An experiment was conducted as factorial based on a randomized complete block design with three replications and eight treatments at the saffron research field of the College of Aburaihan, the University of Tehran during 2015-2016. Experimental treatments included two levels of potassium sulfate fertilizer (0 and 200 kg. ha-1) as the first factor, two levels of Potabarvar-2 biofertilizer (0 and 100 g. ha-1) as the second factor, and two corm weights including small (3-5 g) and big (8-10 g) were the third factors. Potabarvar-2 biological fertilizer used in the research has a set of the most effective potassium-releasing bacteria called Pseudomonas spp. Strain s19-1 and Pseudomonas spp. strain s14-3, which was inoculated with corms before cultivation. Potassium chemical fertilizer treatment of potassium sulfate type and in the amount of 200 kg per was used as pre-planting in the soil of the desired plots. The corms were planted at a distance of 10 cm on the row at a depth of 15 cm at the end of June. In order to increase the colonization of bacteria around the corm, irrigation was done after planting and then summer irrigation was done on the first of September, the appearance of the first flower was at the beginning of November and the end of flowering was in the middle of December. In this research, functional traits including the number of flowers, flower fresh weight, stigma dry weight, and physiological traits including petal anthocyanin, leaf soluble protein, and total leaf soluble carbohydrate were measured.  the results of this experiment indicated that the application of potassium, especially in the form of biofertilizer, had positive effects on improving flowering and increasing the number of flowers in both groups of saffron corms, especially small corms (3-5 grams). Also, the increase in the fresh weight of flowers was evident in the combined application of biological and chemical fertilizers, especially in large corms (8-10 grams). Stigma dry weight increase as an important component of saffron performance was affected by the application of chemical fertilizer, although biological fertilizer also caused a significant increase in this functional trait compared to the control. The application of potassium sulfate in combination with biological fertilizer had the greatest effect on increasing the concentration of total carbon hydrates, total leaf protein, and petal anthocyanin content. Therefore, in most of the measured traits, biofertilizer has positive effects, and to achieve the maximum flower yield and quality of saffron per unit area, biofertilizer alone (100 grams per hectare) or in combination with smaller amounts of potassium sulfate chemical fertilizer should be used. Applied fertilizers led to increasing in flower yield through an enhancement in the number of flowers, fresh weight of flower, and dry weight of stigma. Application of biological fertilizer alone led to an increase of three times the number of flowers in a big corm in comparison with a small corm and normal. There was a significant difference between normal treatment and application of both mixed fertilizers on the concentration of total carbohydrate and protein of the leaf and anthocyanin of the petal.  In summary, the results of this experiment indicated that the application of big corms by inoculating them with biological fertilizer of potassium, in addition to using smaller amounts of potassium sulfate chemical fertilizer before sowing would be affected the increase of flower yield and improve physiological traits effectively growth. Therefore, the use of biological potassium fertilizer led to a decrease of using of chemical fertilizers and will be promising for sustainable agriculture and reducing the environmental pollution.

Leaching and ammonia volatilization are known as the main pathways of nitrogen loss as well as the cause of low nitrogen use efficiency. The present study aimed to study the interaction of five nitrogen fertilizer sources (ammonium sulfate, ammonium nitrate, urea, sulfur coated urea and potassium nitrate) and three soil salinity levels (ECe = 2, 8, and 12 dS/m) on daily as well as cumulative ammonia volatilization. The results showed that salinity and nitrogen fertilizer sources had significant effect on cumulative and daily ammonia volatilization rate. At soil salinity of 2 dS/m, nearly 51%, 44%, 45%, 6% and 0.01% of ammonium sulfate, ammonium nitrate, urea, sulfur coated urea, and potassium nitrate were lost through ammonia volatilization, respectively. These values at soil salinity level of 12 dS/m significantly increased to 73.7%, 54%, 57%, 8%, and 0.01% for ammonium sulfate, ammonium nitrate, urea, sulfur coated urea and potassium nitrate, respectively. In general, the results showed that potassium nitrate had the minimum ammonia loss through volatilization and was followed by sulfur coated urea, urea, ammonium nitrate, and ammonium sulfate, respectively. Regarding the highest nitrogen uptake efficiency and minimum nitrogen loss, potassium nitrate is recommended as the most efficient source of nitrogen fertilizer.

In order to investigate the effect of foliar application on some physiological indicators of growth of barley cultivars, a study in the form of split plots in the form of complete randomized block design with three replications was performed at Kabutar Abad Agricultural Research Station in Isfahan in 2017-2018 cropping year. Treatments included five levels of foliar application ie: no foliar application, zinc sulfate, potassium sulfate, salicylic acid and superoxide dismutase in the tillering phase with an interval of seven days and in three turns, in the main plots and cultivar factor including Goharan, Mehr and Armaghan were placed in the sub-plots. Irrigation was complete and limited. The results showed that foliar application of zinc sulfate increased the leaf area index (50%), relative growth rate (11%), leaf area ratio (54%) and grain yield (18%) compared to the control and the highest leaf area index and leaf area ratio were obtained by the Armaghan cultivar. The highest total dry matter (1027 g.m-2) content and crop growth rate (24.17 g.m-2.day-1) were obtained by salicylic acid and the highest net absorption rate (10.99 g.m-2.day-1) was obtained by control solution. During the growing season, the highest amount of total dry matter, crop growth rate, net absorption rate and relative growth rate were produced by Goharan cultivar compared to other cultivars, which indicates the optimal use of environmental conditions and higher yield production.

Halophytes are one of the essential parts of haloculture that do not compete for the occupation of lands and freshwater resources. Salicornia persica Akhani grows naturally in the southern coastal and desert areas of Iran. This study was conducted to evaluate the effect of two irrigation water quality treatments (seawater and shrimp farm waste-water with electrical conductivity of 64.5 and 66.4 dS m-1 m, respectively) and potassium sulfate fertilizer treatment (with three levels of 0, 100 and 200 kg ha-1) on the amount of forage produced (yield) and height of this plant was investigated in factorial experiment based on randomized complete blocks. The results showed that the yield of Salicornia dry forage under irrigation with seawater and shrimp field waste-water irrigation was 1136.92 and 740.8 kg ha-1, respectively, with significant differences. Investigation of the interaction effects of irrigation treatment (two levels) and potassium sulfate fertilizer (three levels) showed that the highest forage production yield was related to the treatment of 100 kg ha-1 of potassium sulfate fertilizer irrigated with seawater at the rate of 1538.8 kg ha-1 of dry forage .There was no significant difference between plant height related to irrigation treatments and potassium fertilizer application. The results showed that the production of Salicornia under irrigation treatments with seawater and shrimp farm waste-water is possible and consumption of 100 kg ha-1 of potassium sulfate increases yield. Further research was proposed to improve the production potential of this saline plant through agricultural operations and selection of superior germplasms using seawater and shrimp farm waste-water.

 the lack of water resources in arid and semi-arid regions is one of the most important limiting factors of the growth of plants, especially fruit trees. Grapevines are one of the most important horticultural products in the world as well as in Iran. The water content of plant tissues, their growth, and the availability of different nutrients in the soil are significantly reduced under water stress conditions. Therefore, the successful production of the plant under water stress conditions depends on the management of plant nutrition. By application of organic and chemical fertilizers, the physical, chemical, and biological properties of soil can be improved. Besides, it can reduce the adverse effects of drought stress conditions.    

 To evaluate the effect of compost, biochar, and potassium sulfate application on dry matter, relative water content (RWC), chlorophyll a, b, total, and carotenoid contents, as well as the concentration of macro-and micronutrients of leaves of grapevines ‘Bidane-Ghermez’ under two drought stress conditions, this experiment, was conducted in the research greenhouse during 2017-2018. The experiment was carried out as a factorial experiment based on a randomized complete block design (RCBD) with two factors and four replications. The first factor, without drought stress conditions (80% field capacity (FC)), and drought stress conditions (40% FC), and fertilizer treatments included potassium sulfate (1.25 g.kg-1), compost (5 % w/w), and biochar (10% w/w).
  

 The results of the analysis of variance (ANOVA) showed that the interaction effect of drought stress ×fertilizers application was not significant for dry matter, and RWC (P>0.05). Also, the results of ANOVA indicated that the simple effect of drought stress conditions was not significant for dry matter but the simple effect of fertilizer application was significant for leaf dry matter (P<0.01). Without drought stress conditions, there were no significant differences in leaf dry matter between different fertilizer treatments. However, under drought stress conditions, the highest dry matter of grapevine leaves was observed in biochar, compost, and potassium sulfate, respectively. Also, there were no significant differences in leaf dry matter of grapevine between biochar treatment under drought stress conditions and all fertilizer treatments without drought stress conditions. The simple effect of drought stress conditions was significant for leaf dry matter (P<0.05). The results of ANOVA revealed that the interaction effect of drought stress ×fertilizer application was not significant for chlorophyll a, b, total, and carotenoid contents of grapevine leaves. However, the simple effects of drought stress conditions and fertilizer application were significant for chlorophyll a, b, total, and carotenoid contents of grapevine leaves (P<0.01). Relative water, chlorophyll a and carotenoid contents of grapevine leaves were not significantly different among fertilizers treatments. The increase of chlorophyll a/b ratio compared with control was changed in order biochar>potassium sulfate>compost. Moreover, the interaction effect of drought stress ×fertilizer application was significant for nitrogen (N), magnesium (Mg), ferrous (Fe), zinc (Zn), and copper (Cu) concentrations of grapevine leaves (P<0.01). The ANOVA indicated that the simple effects of drought stress conditions and fertilizer application had a significant effect (P<0.01) on macro- and micro-elements concentrations of grapevine leaves. By application of biochar, the concentration of P, K, Mg, and Cu of grapevine leaves significantly were higher than compost and potassium sulfate applications. This consequently resulted in higher chlorophyll a/b ratio and dry matter of grapevine leaves in biochar treatment for control under drought stress conditions.

 Based on the results of this research, it can be concluded that the application of fertilizers reduced drought stress effects on biochemical characteristics and dry matter of grapevine leaves. According to the results, at first the application of biochar is recommended, then potassium sulfate and compost. Our previous results indicated that by application of compost, the available sodium (Na) of soil was increased 8.53 and 60.52 % for potassium sulfate and compost treatments compared to control, respectively. While, by application of biochar, the available Na of soil reduced 3.73 % in comparison with control. This finding is so important regarding the Na effects on soil structure, the toxicity of Na for plants as well as the interaction between Na and K. Considering K is a critical element to regulate the water content of plant tissue and reduces the hazards of water stress conditions, the higher concentration of Na prevents K uptake from the soil solution by plant.

In order to evaluate the effect of deficit irrigation and certain types of potassium fertilizers on some physiological characteristics and antioxidant enzymes activity in rice (cv. Tarom Hashemi), two field experiments were conducted in the Amol and Savadkouh stations. Treatments were different irrigation methods at two levels (flooding, flooding after falling water depth under 10 cm of soil surface) and the application of different potassium fertilizers including potassium sulphate, potassium chloride and potassium biofertilizer at nine levels. Based on the results, relative water content (RWC) and soluble leaf proteins significantly decreased under deficit irrigation in both two stations as compared to flooding irrigation treatment. Also, the accumulation of proline and the activity of antioxidant enzymes such as catalase, ascorbate peroxidase (APX) and guaiacol peroxidase in both two stations, and the amount of hydrogen peroxide and malondialdehyde in the Amol station increased under deficit irrigation. Results demonstrated a positive effect of potassium fertilizer application through significant increment in soluble leaf proteins in both two stations.  Also, RWC and APX activity were increased in Amol station under limited irrigation condition. The highest amounts of grain yield was obtained from the50% of potassium sulfate (as basal) and 50% of potassium chloride (as top dressing) treatment under deficit irrigation that was around 22.8 and 21.5% higher than the control treatment in both Amol and Savadkouh stations, respectively. Generally, results showed an optimal effectiveness of potassium sulfate and potassium chloride application reducing undesirable effects of water deficit stress on rice grain yield.

One of the cultivars of table grape in Iran is Vitis vinifera cv. Askari. But the smallness and non-uniformity of berry size have reduced its yield and attractiveness for consumers. Application of gibberellic acid, nutrients such as potassium as well as 2,4-D at the correct time can enhance the plant growth and fruit development. This study aimed to determine the most suitable gibberellic acid, 2,4-D, and potassium resources on quantitative and qualitative characteristics of Askari grape. This study was conducted on a research farm, on 30-year-old grapevine vines in the Koshkak region of Fars province of Iran in 2016. This experiment was arranged in a randomized complete block design with nine treatments and four replicates. Gibberellic acid at 50 mg/L, 2,4-D at 5, 10 and 20 mg/L, 10 mg/L 2,4-D + 50 mg/L GA3, 50 mg/L GA3 + 10 mg/L 2,4-D + 15 g/L K2SO4, 50 mg/L GA3 + 10 mg/L 2,4-D + 15 g/L KNO3, 50 mg/L GA3 + 10 mg/L 2,4-D + 15 g/L KCl and Distilled water as a control were used. The highest berry and cluster weights and lowest soluble solids content and total phenol were obtained in the treatment of 50 mg/L GA3+10 mg/L 2,4-D+15 g/L K2SO4 with mean of 2.58 g, 214 g and 14.25 ᵒBrix and 58.77 mg/kg, respectively. The lowest berry and cluster weights (1.70-118 g) were obtained from the 20 mg/L 2,4-D treatment. Also, the highest soluble solids content and anthocyanin were obtained from treatment of 20 mg/L 2,4-D with an average of 18.5 ᵒBrix and 41.71 mg/kg, respectively. Results have shown that the use of 50 mg/L of GA3 with 10 mg/L 2,4-D and the use of potassium sources, especially K2SO4 increased the yield and uniformity of the cluster and berry size.

The current study was conducted to investigate the effect of different levels and sources of potassium (K) on seed and oil yields and K uptake of sunflower (Helianthus annuus L.) var. Azargol. The experiment was laid out in randomized complete block design under split plot arrangement with three replications at two locations in West Azerbaijan province during two consecutive years (2017-18). Sunflower sources (K2SO4 and KCl) were arranged in the main plots, accommodating five K doses 0 (control), 100, 200, 300 and 400 kgha-1 in sub-plots. The results indicated that treatment of 100 kgha-1 K from K2SO4 source increased the seed and oil yields by, respectively, 44.8% and 38.6%, which did not differ from the same treatment using KCl. The highest straw weight and biomass were obtained by 300 kg.ha-1 K from K2SO4 source, which increased by 58.9% and 51.8%, respectively, compared to the control. K uptake by straw was 2.93 times more than the grain. Sunflower reduced native available potassium (Kava) by 32 mg.kg-1. K uptake in grain was 141.2 kg.ha-1, which enhanced with increasing potassium level treatments. The soil Kava was proportional to potassium level treatments. The maximum soil Kava was 410 mg.kg-1, with application of 400 kg.ha-1 of K. In this connection, K sourcaes had the same effect. The results suggested that by application of 100 kg K.ha-1  from K2SO4 or KCl in oil-seed sunflower cultivation, in addition to producing a suitable product, Kava of the soil is maintained in optimum range.

Grapes are one of the most important garden products in the world as well as in Iran. The management of plant nutrition under water stress conditions is one of the important issues in the production of the plant. When the plant has adequate nutrition, it will result in higher resistance to environmental conditions. The use of organic and chemical fertilizers as amendments of the physical, chemical and biological properties of soil can be one of the strategies to reduce the adverse effects of drought stress.

In order to evaluate the effect of potassium sulfate, compost and biochar on some soil properties and grapes nutritional status under water stress conditions, a greenhouse experiment were carried out as a factorial experiment based on a block of randomized completely design with two factors and four replications. Water stress had two levels (40, 80 % FC) and fertilizers’ treatments included potassium sulfate (10 g pot-1), compost (5 % w/w) and biochar (10% w/w). The macro- and micro-elements’ contents of grapes’ leaf and soil properties included the macro and micro-elements, pH, EC, OC. were also measured.

The results showed that the interaction effect of water stress and fertilizers’ treatments was significant for nitrogen(N), magnesium (Mg), ferrous (Fe), zinc (Zn) and copper (Cu) concentrations of grapes’ leaves (P<0.01). ANOVA indicated that the simple effects of water stress and fertilizers’ application had a significant effect (P<0.01) on macro- and micro-elements’ concentrations of grapes’ leaf. The results also showed that under water stress conditions, the highest N concentration was observed for compost and potassium sulfate applications. Without water stress conditions, there was no significant difference between treatments. Under the water stress conditions, the highest concentration of Mg of grapes’ leaves was achieved with biochar application. While without water stress conditions, the lowest concentration of Mg was observed for biochar treatment. With and without water stress conditions, the concentration of Fe and Cu was higher for organic treatments compared to potassium sulfate application. With and without water stress conditions, the highest concentration of Zn was achieved for potassium sulfate application. The ANOVA results showed that the interaction effect of water stress and fertilizers’ treatments was not significant for soil properties except soil calcium. The water stress caused a significant decrease in soil phosphorus (P) and Mg (P<0.05) as well as calcium (Ca) (P<0.001). The effect of fertilizers’ treatments was significant on electrical conductivity, organic carbon, N, P, potassium (K), and sodium (Na) (P<0.01), Ca and Mg (P<0.001) concentrations of soil. The application of potassium sulfate and compost increased the Na concentration of soil as 8.53 and 60.52 percent, respectively. While the Na concentration of soil decreased as 3.73 percent with the biochar application.

Under water stress conditions, the application of compost and biochar in comparison with potassium sulfate enhanced the nutritional status of grapes because of the improvement of soil fertility status. The highest K concentration and uptake of grapes’ leaves and soil were observed with biochar application. Under water stress conditions, in comparison with no fertilizer application, K uptake increased as 69.85, 36.21 and 178.97 percent by potassium sulfate, compost and biochar applications, respectively. Since K is a critical element to regulate the water content of plant tissue and reduces the hazards of water stress, the application of compost and biochar is recommended for the improvement of plant resistance under water stress conditions. However, biochar is suggested due to properties such as highly porous structure, high specific surface area, higher water holding capacity of the soil, the long-term stability in the soil and the reduction of Na hazards in soil.

Fertilization is one of the most important management tools in horticulture playing an important role in nutrition of fruit trees in order to improve the yield and quality. A factorial randomized complete block design experiment with 3 replications was conducted to investigate the effects of potassium sulphate (0, 50, 100 and 150 g/tree) and iron chelate (0, 10, 20 and 30 ml/tree) during Red Delicious apple tree growth. Some traits including branch length, chlorophyll index, fruit length and width, fruit weight, fruits number, leaf area index and concentration of some nutrients in leaves were measured. The results showed that potassium sulfate and iron chelate improved all growth traits. Potassium sulfate and iron chelate showed a positive and significant increase in yield. With increase in concentration of potassium sulfate, the amount of phosphorus and potassium in leaves was increased, while iron chelate decreased the amount of phosphorus. The highest amount of magnesium was observed in the absence of potassium sulfate treatment and treatment with 30 cc of iron chelate. The highest amount of iron was observed in the case of treatment with 20 and 30 cc of iron chelate with no potassium sulphate application. Also, with the application of potassium sulfate fertilizer, the amount of calcium and copper in the leaves was decreased. Fertilization had no significant effect on the concentration of nitrogen, zinc and manganese in the leaves.

Water deficit in soil is a common phenomenon in plant cultivation and can have significant negative effects on their growth. Potassium is an element that increases the resistance of plants to dehydration, salinity stress. If the amount of potassium is reduced, the apertures will not function properly and will disrupt the photosynthesis process and the rate of growth of the crop.The use of biological fertilizers composed of bacteria and fungi can help to optimize the use of fertilizers. These fertilizers, by dissolving the mineral compounds of the soil, facilitate the absorption of the elements by the plants. Therefore, the present study was conducted to investigate the effect of the combined use of potassium chemical and biological fertilizers in order to modify the effects of soil moisture deficiency on yield and yield components of wheat. In order to modify the effects of soil moisture shortage on yield and yield components of wheat, an experiment was carried out based on factorial with completely randomized block design with three replications during 2015-2016 in Ahvaz region. The first factor was irrigation regimes on basis of evaporation from evaporation pan at three levels include: 60 mm (common area), 90 mm and 120 mm. The second factor including combination of chemical and biological of potassium include, 1-completely through potassium sulfate fertilizer (without bio-fertilizer) (control), 2-75% potassium sulfate+Potabarvr2, 3-50% potassium sulfate+Potabarvr2 and 4-25% potassium sulfate+ Potabarvr2.The application of irrigation treatments started at the beginning of the tillering and continued the final harvest. To fertilize the seeds with bio-fertilizer Potabarvar 2, the seeds were first wet, then spread on plastic surfaces, and with Pb-2 biofertilizer, 100 grams per hectare per hectare were seeded on the basis of the manufacturer's recommendation. Potassium fertilizer was used as the basis for the treatment of 100 kg of pure potash per hectare from the source of potassium sulfate as a base and before planting. The results showed that the effect of irrigation was significantly different on ear number per square meter, grain number per spike, 1000-grain weight, grain yield, biological yield and harvest index. The effect of combined application of fertilizer on all traits was significant except harvest index. The maximum number of spikes per square meter, grain number per spike, 1000 grain weight, and harvest index belonged to irrigation based on 60 mm evaporation pan and the lowest was 120 mm evaporation pan. Also, the maximum number of spikes per square meter, number of seeds per spike, 1000 grain weight and harvest index were 75% potassium sulfate + Potabarvr2.In regard to grain yield , the maximum was obtained under 60 mm evaporation and 75% potassium sulfate + Potabarvr2 by 5970 kg/ha. The minimum grain yield was under 120 mm evaporation and 25% potassium sulfate + Potabarvr2 by 2994 kg/ha. The overall results of this study showed that: 1- With increasing moisture stress, traits such as grain yield, yield components, harvest index and biological yield decreased. Reduction in grain yield was higher than biological yield, indicating greater sensitivity of reproductive organs to vegetative organs under moisture stress conditions. 2. With the application of potassium sulfate, conditions can be established for plant establishment and ultimately increased yield. The best yield and yield traits were observed in 75% potassium sulfate + Potabarvr2. The use of bacteria seems to have affected the plant by increasing the potassium bioavailability or by producing growth regulating hormones. On the other hand, due to the fact that in all three irrigation regimes, grain yield increased by 75% potassium + Potabarvr2 sulfate in comparison with non-use of biological fertilizers (control) (all through potassium sulfate). Therefore, this fertilizer combination can be recommended in the moisture stress and without stress conditions in the region.

Rice is an important cereal in the diet of many people in the world and Iran. An overuse of chemical fertilizers in rice fields also causes environmental problems so that the use of biofertilizers as an appropriate alternative is important for producing healthy crops and reducing environmental hazards. Therefore, in order to evaluation of the effect of Pantoea ananatis and Piriformospora indica on yield, yield components and potassium uptake of rice(cv. ‘Tarom Mahalli’), a field experiment was carried out in Joybar city in 2016. The experiment was conducted in a split plot arrangement based on randomized complete block design with three replications. Four levels of potassium sulfate fertilizer (PSF: 0, 60, 120 and 180 kg.ha-1) were used as the main plot and four levels of inoculation (non-inoculation as control, rice root seedling inoculation with P. ananatis and P. indica, separately, and co-inoculation treatment) served as the sub-plots. The results indicated that all studied traits such as panicle number per hill (PN), panicle length (PL), number of filled (NFG) and empty (NEG) grain per panicle, paddy yield (PY), biological yield (BY), harvest index (HI) and potassium uptake (PU) in the grain of rice were significantly affected by PSF and various inoculation treatments and also the interaction effect between them were statistically significant in more studied traits. Co-inoculation treatment significantly increased PN, PL, NFG, PY, BY, HI and PU by 4.52, 4.65, 15.7, 19.4, 6.85, 11.7 and 22.1 percentage, respectively, and the NEG was decreased by 41.8 percentage as compared to the control. Furthermore, values of all studied traits increased with the addition of PSF from zero to 180 kg.ha-1, except for NEG. According to the results of regression analysis, consequently, the co-inoculation treatment as the best, reduced the application of PSF ~55.5 kg.ha-1 (about 40%) and increased PY ~790 kg.ha-1 (about 18.6%), compared to the control which can be used in the sustainable rice system production as well as.

To study the effect of potassium source and application rate on qualitative characteristics of sugar beet, a field experiment was conducted at county of Jovein, Khorasan Razavi, during 2010-2011. Experiment was carried out as split factorial in a randomized complete block design with three replications. Experimental factors included two irrigation regimes (full and deficit irrigation), two potassium sources (potassium sulfate and potassium chloride) and three potassium application rates (0, 50 and 100 kg K2O ha-1). Results showed that deficit irrigation increased sodium content of root by 16.8 percent compared with full irrigation. However, other qualitative characteristics of sugar beet were not influenced by irrigation treatments. Application of potassium chloride, increased root dry matter percent and decreased root nitrogen content compared with potassium sulfate. The sugar percent, white sugar percent, sugar purity and root alkalinity increased and molasses sugar percent, root potassium, sodium and nitrogen content decreased with increasing potassium application rate. The highest sugar percent (19.92), white sugar percent (17.96), sugar purity (90.70%) and root alkalinity (2.77) and also the lowest molasses sugar percent (1.82), root potassium (5.03 meq/100 g root) , sodium (1.35 meq/100 g root) and nitrogen content (2.39 meq/100 g root) were observed in 100 kg K2O ha-1 treatment. According to the results, in similar climatic conditions, the use of large amounts of potassium, particularly in the form of potassium chloride, is recommended for improving the qualitative characteristics of sugar beet under full and deficit irrigation conditions.

In order to study the effect of humi potas and potassium sulfate on some morphological traits of Stockflower, this research was conducted at Research Farm of Shahid Chamran University in Ahvaz in 2015. This experiments was performed as factorial bassed on RCBD with three replications. Treatments included humi potas with 3 levels of 0, 500 and 1000 mg l-1 and potassium sulfate fertilizer with 3 levels 0, 50 and 100 kg / h. During growth period, Evaluated vegetative indices (length and diameter of stem, number and leaf area) In 6 stage at intervals every 21 days once and reproductive characteristics (Flower durability, number of days to flowering and seed yield per square meter) at the end stage of plant growth.Treatments with Humi potas were effective on the vegetative properties of stem diameter, leaf number and leaf area, and on the reproductive characteristics of days to flowering and Flower durability. Treatment with potassium sulfate was significant only on stem length and diameter characteristics. the interaction of Humi potas fertilizer and potassium sulfate also showed a significant effect on the growth characteristics of stem diameter, number and leaf area, Flower durability and seed yield. The highest stem diameter, number of leaves, leaf area and Flower durability were related to interaction treatment (1000 mg/l Humi potas and 100 kg/ha potassium sulfate). Overall, it can be said that the use of Humi potas fertilizer in combination with potassium sulfate fertilizer, in addition to improving the growth characteristics of Flower, can play a positive role in decreasing the use of chemical fertilizers and reducing environmental pollution.

One of the aims of Iranian farmers is self-sufficiency in rice production. To purpose this aim according to the sustainable agricultural laws, it is important to use an appropriate agronomic management such as improving use of chemical fertilizers and or application of biofertilizers in both method; alone and or along with declined chemical fertilizers. Also, use of renewable inputs such as plant growth promoting microorganisms (PGPM; with the ability of biological nitrogen fixation, solubilize insoluble minerals like phosphorus and potassium, phytohormone production and or production of enzymes and organic acids) with high ecological benefits and low environmental damages is necessary today. Therefore, this study aimed to evaluate the efficiency of two PGPM on some vegetative characteristics and grain yield (GY) of rice (cv. ‘Tarom Mahali’) at different amounts of potassium sulfate fertilizer (PSF). A field experiment was conducted in a paddy field of Mazandaran province (Juybar city) as a split plot based on a randomized complete block design with three replications in 2016. Four levels of PSF (zero, 60, 120 and 180 kg ha–1) were used as the main plot and four levels of inoculation with PGPM (Pantoea ananatis and Piriformospora indica were applied individually and a co-inoculation with Pa. ananatis and Pi. indica (50:50) and non-inoculated as control) served as the sub plots. Based on the results of soil test, 50 kg ha–1 of triple super phosphate and all levels of PSF were used before transplanting time and 150 kg ha–1 of urea was applied twice (100 and 50 kg ha–1 at transplanting and heading stage, respectively). At anthesis stage, some vegetative characteristics including plant height (PH), total number leaves hill-1 (TNL), leaf area index (LAI), total tillers numbers hill-1 (TTN) and the time of beginning anthesis stage (BAS) were measured. GY was also determined at harvesting time by removing of 1 m–2 of rice plants from each plot. The results of this study indicate that all studied traits significantly affected by the simple effect of PSF and PGPM inoculations and also their interactions was significant at 0.01 and 0.05 probability level. As PSF increased from 0 to 120 kg ha-1, the significant increase in PH (from 142.1 to 150 cm), TTN (from 9.2 to 11.0 count), TNL (from 64.2 to 65.4 count), LAI (from 3.9 to 5.6) and GY (from 448.8 to 585.7 gr m-2) was 6, 20, 2, 41 and 30%, respectively, as compared to the control. In addition, BAS decreased significantly by 2.3% (from 57.6 to 56.2 days after transplanting), as compared to the control (without PSF). Although, an increasing of PSF from 120 to 180 kg ha-1 resulted in an increase in all studied traits, but differences were not statistically significant among treatments. In addition, single inoculations with Pa. ananatis, Pi. indica and co-inoculation treatment significantly increased PH by 4.4, 4.1 and 3.4%, TTN by 8.7, 8.7 and 22.7%, TNL by 2.8, 2.4 and 4.4%, LAI by 13.1, 15.0 and 27.2% and GY by 11.2, 11.2 and 19.4% and decreased significantly BAS by 2.0, 2.0 and 3.3%, as compared to the control (non-inoculation), respectively. Based on our finding the co-inoculation with Pa. ananatis and Pi. indica as the best treatment, improved the values of all studied traits when compared with the control condition. In general, application of this treatment resulted in decreasing PSF about 55 kg ha-1 (40 % lower than the control) and increasing GY about 79 gr m-2 (18.6% more than the control). Consequently, these PGPM can be used along with lower values of PSF as well as, particularly in sustainable rice cultivation systems.

Persian walnut is one of the most important nut crops originated from central Asia particularly Iran. According latest statistics of FAO Iran with 65,000 hectares under cultivation and produce 170,000 tons of walnuts is fourth largest producer of walnut in worlds. Adding the correct nutrients to the soil has been the highest effect on the growth and yield of walnuts. In order to, factorial experiment in a randomized complete block design with three levels of N (0, 200 and 400 N kg ha-1 Ammonium sulfate) and three levels of Potassium (0, 150 and 300 K kg ha-1 Potassium in four replications was evaluated in the bondar gardeshgari village. . The results showed that Increase of Nitrogen significantly affected concentration of Nitrogen, Phosphorus, Calcium and Micro elements in the leaves. By Increasing Nitrogen application significant increase of Nitrogen, phosphorus, Iron, Manganese, copper and Zinc concentration in the leaves but decreased Calcium and Potassium concentration. By increasing application of Potassium sulfate fertilizer application significant but decreased Calcium and Nitrogen concentration. That’s indicating Antagonist Relationship of these elements.By Increasing Nitrogen application significant increase of Nitrogen, phosphorus, Iron, Manganese, copper and Zinc concentration in the leaves but decreased Calcium and Potassium concentration. By increasing application of Potassium sulfate fertilizer application significant but decreased Calcium and Nitrogen concentration. That’s indicating Antagonist Relationship of these elements.