Plant Nutrition, Soil Fertility and Fertilizers
Amir Rahimi; Behnam Doulati; Saied Heydarzadeh
Abstract
Introduction Nutritional deficiencies (e.g. Iron, Zinc, Manganese and Boron) account for almost two‐thirds of the childhood death worldwide. Most of those afflicted are dependent on staple crops for their sustenance. Declining soil fertility in many countries, duo to continuous cropping systems, has ...
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Introduction Nutritional deficiencies (e.g. Iron, Zinc, Manganese and Boron) account for almost two‐thirds of the childhood death worldwide. Most of those afflicted are dependent on staple crops for their sustenance. Declining soil fertility in many countries, duo to continuous cropping systems, has reduced soil production capacity affected by depletion of soil nutrient without proper replacement. Soil application of prepared humic substances is not economical, but the response to foliar sprays has the potential to be economical because the relatively small quantities are needed. Foliar application is one of the swift response methods for plants to add fertilizer, which leads to dispel of nutrients deficiency and providence in the use of chemical fertilizers. The solubility of nutrients decreases in soils with high acidity or undesirable chemical composition and can be possibility of ionic competition (Antagonism) or the accumulation of nutrient in soilcanlee resulthed. Therefore, adsorption of nutrients and root growth will be inappropriate. On the other hand, the application of humic substance with improving physical, chemical and biological conditions causes an increase in adsorption and soil fertility. Using humic substances is another benefit of the reduction of environmental pollution in order to achieve sustainable agriculture. A sugar beet is a plant whose root contains a high concentration of sucrose and which is grown commercially for sugar production. Sugar beet is one of the strategic crops and is widely cultivated in the West Azerbaijan region. So, the aim of this study was to investigate the application of humic substances and micronutrient on some quantitative and qualitative characteristics of sugar beet. Material and Methods This study was carried out as a randomized complete block design with six levels of humic substance (0, 200, 300, 400, 500, 600 kg ha-1) and foliar application of micronutrients including Fe, Zn, B, and Mn with 3 replications. Physicochemical properties of soil (calcium carbonate equilibrium, pH, OC, EC, micro and macro elements, soil texture) were determined by standard methods. There fore, quantitative and qualitative characteristics of sugar beet including total sugar content, pure sugar content, and molasses sugar content, Na, K and N content in root, alkalinity, sugar extraction coefficient, root yield and pure sugar and total sugar yield were determined in sugar beet samples. Results The results showed that the application of humic and micronutrient was significant in qualitative and quantitative characteristics of sugar beet. Maximum root yield (68.96 ton ha-1) was obtained in the Mn treatment. The highest of pure (16.30%), gross sugars (18.68%) and sugar extraction coefficient (87.25%) was observed in B and 500 kg ha-1 of humic asid treatment. Humic acid application increased nitrogen (27.58%) and root yield (29.08%) compared to control. Also, micronutrient and humic substance application reduced the molasses sugar content and increased potassium in the root of sugar beet. So that the highest (3.48%) and lowest (2.37%) amounts of molasses sugar were obtained in control and 500 kg ha-1 humic acid plus B treatment respectively. Boron is much required for cell division and development in the growth regions of the plant near the tips of shoots and roots. It also affects sugar transport and appears to be associated with some of the functions of calcium. Conclusion According to the results of this study, foliar application of humic substance and micronutrient improved qualitative and quantitative characteristics of sugar beet. The root and refined sugar yields are among the most important components in sugar beet production. Also, treatment of 600 kg ha-1 of humic acid and Mn spraying had the greatest effect on the root and gross sugars yield in sugar beet. Also, the amount of molasses sugar decreased with increasing sugar content and replacing potassium instead of harmful elements. Application of Mn and B may need to be considered for sugar beets. Foliar fertilization with Mn has the beneficial effect mainly on such features like White sugar yield, root, gross sugars yield, and the number of leaves per single sugar beet plants. It can be concluded that the contemporary use of humic substance and micronutrient is recommended in order to achieve adequate yield and preserve the environment.
Plant Nutrition, Soil Fertility and Fertilizers
Faranak Ghasemi; ُSaeid Hojati; Ahmad Landi; Roya Zalaghi
Abstract
Introduction Clay minerals are considered as the main source of ion exchange and storage of nutrients in the soil. Knowledge of change and transformation of minerals, in relation to plant nutrition, fixation and release of elements is important. Sepiolite and palygorskite are fibrous clay minerals widely ...
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Introduction Clay minerals are considered as the main source of ion exchange and storage of nutrients in the soil. Knowledge of change and transformation of minerals, in relation to plant nutrition, fixation and release of elements is important. Sepiolite and palygorskite are fibrous clay minerals widely distributed in arid and semi-arid soils. Both minerals are rich in Mg and therefore, their weathering can significantly affect the chemistry of Mg in soil. Biological weathering which is carried out by living organisms (i.e. plant roots, soil fungi and bacteria) plays an important role in providing nutrients to plants. Hence, the use of microorganisms such as mycorrhizal fungi in the rhizosphere of agricultural crops has become more widespread. In recent years several studies have been conducted in relation to the weathering of minerals in the rhizosphere soil. However, few studies in terms of mycorhizal symbiosis with plant roots were carried out on release of Mg from sepiolite and palygorskite. Therefore, a pot experiment with a factorial arrangement through a completely randomized design was conducted to identify how symbiosis of sorghum roots with Glomus mosae mycorhizae affects release of Mg from sepiolite and palygorskite. Materials and Methods Pots containing sterile quartz sand and sepiolite or palygorskite (25-53 µm) were prepared and fungal treatments including presence or absence of fungus Glomus mosae were applied to the pots and then sorghum seeds were sown. Johnson nutrient solutions containing magnesium and without magnesium were used to feed plants during 70 days of experiment. After harvesting, the chlorophyll content, plants height and stem diameter were measured by SPAD, tape measure and caliper, respectively. Afterwards, the roots and shoots were separated and plants biomass and the percentage of roots colonization determined. Then, plants were oven-dried, ground, and the magnesium contents of them after extraction with 1M hydrochloric acid were determined using Agilent 7000 ICP analyzer. The chemical composition of palygorskite, sepiolite, and quartz sand was determined using X-ray fluorescence (XRF) and their mineralogical composition was determined using X-ray diffraction (XRD) approach. Results and Discussion Analysis of variance for the main effect of treatments on plant height, stem diameter, shoot dry weight and root dry weight showed that the effect of different sources of magnesium on plant height, stem diameter and shoot dry weight was significant (P < 0.01). The highest and lowest height, stem diameter, root and shoot dry matter were found in treatments fed with complete Johnson solutions and the palygorskite, respectively. The results also illustrated that application of Glomus mosae symbiotic mycorhizae significantly increased plant height, stem diameter, and root and shoot dry matter compared with non-mycorhizal treatments. This could be attributed to the fact that Mycorrhizal fungi (Glomus mosae) absorb more water and nutrients through increased photosynthesis and plant growth, consequently leading to improved plant characteristics when compared with non-mycorhizal crops. The results also showed the highest percentage of root colonization in palygorskite treatments and the lowest one in control. In general, a symbiotic relationship is created to improve low nutrition of elements that the amount of them in the soilwith a little mobility. Therefore, anything that exacerbates this deficiency, leads to an increase in symbiosis between plants and fungi. On the other hand, When plant is faced with more nutrient deficiencies, the demand for a symbiothic fungusGlomus mosae increases. Besides, the greatest magnesium concentration and chlorophyll contents were found in control, sepiolite and palygorskite treatments, respectively. In all treatments, magnesium intake was sufficient to grow sorghum, but as the results show, the amount of magnesium in the control and that of sepiolite was much more than palygorskite. These results clearly show that sepiolite mineral is able to release more Mg than palygorskite. The results also showed that the presence of the fungus Glomus mosae has significantly affected the release of Mg from both minerals. Conclusion In both sepiolite and palygorskite treatments, magnesium and chlorophyll content increased in symbiosis with fungi. This shows the positive effect of Glomus mosae fungus on release of Mg from these two minerals, especially sepiolite. Although, both sepiolite and palygorskite were able to provide enough amounts of Mg for sorghum plants, however, it seems that in long-term Mg released from sepiolite can more easily meet the need of plants when compared with palygorskite.
Plant Nutrition, Soil Fertility and Fertilizers
Soraya Taheri; abdolmajid ronaghi; Reza Ghasemi; Sedigheh Safarzadeh Shirazi
Abstract
Introduction Zinc deficiency is aggravated mainly in arid and semi-arid regions, due to low organic matter and soil moisture as well as high levels of pH and salinity. Maize which serves as staple food is sensitive to Zn deficiency. One of the mechanisms by which plants can adapt to nutrient deficient ...
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Introduction Zinc deficiency is aggravated mainly in arid and semi-arid regions, due to low organic matter and soil moisture as well as high levels of pH and salinity. Maize which serves as staple food is sensitive to Zn deficiency. One of the mechanisms by which plants can adapt to nutrient deficient soils has suggested producing and secreting organic substances, including aliphatic low molecular weight organic acids, into the rhizosphere for mobilization and uptake of nutrients. Under Zn deficiency, plants tend to modify rhizosphere in order to increase Zn phyto-availability. Zinc mobilization efficiency is dependent upon the amount and type of organic acids exuded by plant roots and physiochemical properties of soil. Therefore, the objectives of the present study were to investigate the influence of Zn deficiency on the shoot and root dry matter yields and the release rate of organic acids (malic, citric and acetic acids) commonly identified in root exudations of maize under Zn deficiency conditions. Materials and Methods Seeds of maize (SC703 and SC704) were surface sterilized and germinated in perlite moistened with distilled water. After seven days, the seedlings were transferred to 5-L containers with continuously aerated nutrient solution. Three Zn levels (0, 0.5, and 1 µM) were added to nutrient solutions. Ten weeks after maize emergence, intact plants were removed from nutrient solution and after two hours of the onset of the light period, roots samples were in opaque vessels containing fresh solution. The volume of collected solution was sufficient to submerge the whole maize roots samples. After three hours, roots samples were removed from the vessel and solution containing roots exudates was filtered and frozen at −20 ◦C until analysis of organic acids was performed. Organic acids were analyzed using high performance liquid chromatography (HPLC). Organic acids in the samples were identified by comparison with the retention time and absorption spectra of pure standards including malic, citric and acetic acid. The 1-cm washed root segments were placed in a beaker containing 10 mL deionized water and then root samples were immersed at 30◦C for three h, and then conductivity of solution was measured. The samples were boiled for 2 min, cooled to room temperature (25◦C) and then EC samples were measured. The electrolyte leakage was calculated as follows: Where C1 and C2 are electrical conductivities measured before and after boiling, respectively. Roots and shoot samples were ignited at 580 ◦C in an oven for 5 h and Zn concentration measured using atomic absorption spectroscopy (AAS). Results and Discussion In both genotypes shoot dry matter yield (SDMY) was significantly improved with increasing Zn concentration in nutrient solution. The highest value of SDMY was 19.8 g and belonged to Zn-adequacy level (1 µM) in SC703 genotype which had no significant difference with SC704 under the same treatments. There was no significant difference between Zn-sufficient and Zn-deficiency (0.5 µM) in SDMY in genotype SC703 whereas, a significant difference was observed at the same treatments in genotype SC704. The lowest value of SDMY was 14.7 g and belonged to the Zn-free treatment for genotype SC704. Root dry matter yield (RDMY) significantly increased with increasing Zn concentration in nutrient solution in both genotypes. The highest value of RDMY was 9.6 g and belonged to the treatment of Zn-adequacy for SC703 genotype which had no significant difference with SC704 genotype under the same treatment. The lowest value of RDMY was 4.8 g which was observed in Zn-free treatment for SC704 genotype. Results showed that the rate of organic acid exudation in both Maize genotypes decreased with increasing Zn levels in nutrient solution. The highest rate of MA exudation (6.6 mg /g root dry weight) was observed in Zn-free (Zn0) treatment in SC703 genotype and the lowest rate (1.98 mg g RDW-1) was observed in 1µm Zn treatment in SC704 genotype. Similar to MA, the rate of citric acid (CA) exudation rate significantly decreased with increasing Zn levels in nutrient solution. The highest rate of CA exudation rate was 1.06 (mg gRDW-1) and observed in Zn-free (Zn0) SC703 genotype. The lowest rate of CA was observed in 1µm Zn treatment SC704 genotype 0.2 (mg gRDW-1). The concentration of acetic acid (AA) was below the detection limit of HPLC in Zn sufficient and Zn deficiency treatments. However, AA concentrations in Zn-free were 0.66 and 0.25 (mg gRDW-1), respectively in SC703 and SC704 genotypes. The rate of MA was significantly higher than CA (4times) and AA (15 times higher). All organic acids exudation rate decreased with increasing Zn concentration in nutrient solution. There was a negative relationship between root and shoot Zn concentration with MA and CA exudation rate. MA, CA and AA exudation rate decreased as the concentration of Zn increased in root and shoot of maize. Roots membrane permeability decreased with increasing Zn concentration in nutrients solution which led to the reduction in root exudations. In both maize genotypes, the highest rate of root membrane permeability belonged to the Zn-free treatment (Zn0) which had the highest root exudation of organic acid and the lowest rate was observed in1µM Zn level with the lowest rate of organic acid exudation. It seems that Zn concentration in maize shoot control the release of root exudation of organic acids. In general, based on the results it can be concluded that SC703 genotype was more tolerant to Zn-deficiency compared to SC704 genotype partly due to the higher release rate of root organic acids. Further investigation is required to fully understand the physiology of organic acids release under Zn deficiency conditions.
Plant Nutrition, Soil Fertility and Fertilizers
Ali Abdolahi; Mehdi Taghavi; Mojtaba Norouzi masir; Abdolamir Moezzi
Abstract
Nanotechnology has created a range of new applications in different stages of agriculture. The application of Nano-fertilizers for plants is of vital importance because of its unique properties, such as the specific surface and high reactivity. Many studies have investigated the effect of metal nanoparticles ...
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Nanotechnology has created a range of new applications in different stages of agriculture. The application of Nano-fertilizers for plants is of vital importance because of its unique properties, such as the specific surface and high reactivity. Many studies have investigated the effect of metal nanoparticles on yield and concentration of elements in the plant. The present study was conducted with the aim of investigating the effects of Functionalized Iron Oxide Nanoparticles (FIONPs) on plant yield, concentration and uptake of Zinc in root and shoots of wheat under greenhouse cultivation in a calcareous soil. Materials and Methods This study was conducted in the greenhouse condition as a randomized complete design with three replications. Treatment consisted of functionalized iron oxide nanoparticles (Hydroxyl: OH, Carboxyl: COOH and Amine: NH2) each at three levels (100, 200 and 300 mg.kg-1), ZnSO4 (40 kg.ha-1) and Control. During the experiment, some parameters such as the plant height and chlorophyll index were measured. At the end of the cultivation period, dry weight and Zn concentration of root, shoot and grain was determined using Atomic absorption apparatus (Perkin elmer A_Analyst 200 model). Likewise, content of soil available Zn was measured using DTPA. Results The amount of available zinc in all levels of iron oxide nanoparticles, except Amine iron oxide nanoparticles (at levels of 200 and 300 mg / kg), was significantly (p < 0.01) increased compared to control. The maximum amount of soil available Zn were observed in levels of 300, 200 and 100 mg.kg-1 Carboxyl iron oxide nanoparticles with 83.64, 70.91 and 63.64% increment compared to control, respectively. Effect of treatments of functionalized iron oxide nanoparticles and zinc sulfate on chlorophyll content, plant height and dry weight of shoots was significant (p < 0.01). The maximum yield of root and shoot was obtained at the level of 300 mg.kg-1 of Carboxyl iron oxide nanoparticles with 34.74 and 25.1% increment compared to control, respectively. The maximum grain yield was observed at the level of 300 mg.kg-1 of Carboxyl iron oxide nanoparticles with 36.51% increment compared to control. The maximum chlorophyll content was obtained in Carboxyl iron oxide nanoparticles (at level of 300 mg. kg-1) with 11.38% increment compared to control. The maximum of Zinc concentration in root, shoot and grain was observed at the level of 300 mg.kg-1 carboxylic oxide nanoparticles with 103.62, 159.26 and 26.87% increment compared to control, respectively. Conclusions The results showed that application of FIONPs improved soil pH and subsequently available zinc of soil. Also, nanoparticles increased the yield, concentration and uptake of zinc in root, shoots and grain of wheat. Therefore, based on the obtained results from this study, it can be said that use of new strategies such as nanoparticles can be useful in improving soil conditions and bioavailability of Micronutrient like Zinc and reducing chemical fertilizers.
Plant Nutrition, Soil Fertility and Fertilizers
Esmaeil Dordipour; Zeinab Bastamikojour; Mojtaba Baranimotlagh; Abdolreza Gharanjiki; Mohsen Olamaee
Abstract
Introduction The most important constraint in maize crop yield in developing contries worldwide, and especially among resource-poor farmers, is soil infertility. Therefore, maintaining soil quality can reduce the problems of land degradation that decreases soil fertility and rapidly declining production ...
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Introduction The most important constraint in maize crop yield in developing contries worldwide, and especially among resource-poor farmers, is soil infertility. Therefore, maintaining soil quality can reduce the problems of land degradation that decreases soil fertility and rapidly declining production levels that occur in large parts of the world which needing the basic principles of good farming practice. For optimum plant growth, nutrients must be available in sufficient and balanced quantities. After nitrogen, phosphorus is the most limiting nutrient for crop yields, and is essential for maize growth and development. Large quantities of chemical fertilizers are used to replenish soil N and P, resulting in high costs and severe environmental contamination. Maize quantity and quality are increased by utilization of fertilizers, which has become the most important objective of these products worldwide. Phosphorus, is the second most important macronutrient required by the plants, next to nitrogen, and is reported to be a critical factor of many crop production systems due to its limited availability in soluble forms in the soils. The low availability of P to plants is because the vast majority of soil P is found in insoluble forms, and plants can only absorb P in two soluble forms, the monobasic (H2PO4-) and the dibasic (HPO42-) ions. Crop plants can therefore utilize only a fraction of applied phosphorus, which ultimately results in poor crop performance. To rectify this and to maintain soil fertility status, frequent application of chemical fertilizers is needed, though it is found to be a costly affair and also environmentally undesirable. Moreover, phosphorus (P) is an essential nutrientionl element for plant growth. Calcareous soils are frequently characterized by the low availability of P for plant uptake due to the low solubility of P compounds present in soils at high pH and the formation of relatively insoluble complexes, e.g., Ca-P. Many soils in Iran have received large amounts of P fertilizer and consequently contained a high level of available P. On the other hand, the root exudation of organic acids has been suggested to increase P availability in calcareous soils. The most common low-molecularweight organic acids (LMWOAs) identified in soils include oxalic, succinic, tartaric, fumaric, malic, and citric acids and are derived from the decomposition of soil organic matter in the upper soil horizons, microbial metabolites, canopy drip, and root exudation. The concentrations of organic acids in the rhizosphere or in soil solutions vary greatly and range from 10-2μM to over 80 mM. The ability of organic acids to release inorganic anions, such as P, has been reported and has been attributed to desorption of inorganic anions and solubilization of phosphate compounds. LMWOAs and their corresponding anions play a very important role to increase P bioavailability. Many studies have been conducted about the role of organic acids in increasing P availability, but these studies focused on acid soils in which Fe- or Al-bound P is the main P fraction. For calcareous soils where Ca-bound P is the main P fraction, questions that whether organic acids can mobilize P or not still exist. Although, a number of results show that addition of organic acids, especially citric and oxalic acids to soils can solubilize significant quantities of fixed P and reduce the sorption of newly applied fertilizer P. However, there are few studies on the transformations of P fractions induced by organic acids or organic anions, which are important for understanding the mobilization mechanisms of P and for exploring better ways of using different forms of P in soils. The objective of this study is to examine the effects of some organic acids and anions on the solubilization and plant uptake of soil P in some calcareous soils of Golestan province, Iran. Material and Methods For this purpose, a factorial pot experiment in a completely randomized design with three replications was conducted on maize. The first factor was comprised of 6 soil types from various areas of the province and the second factor was consisted of a combination of phosphorus fertilizer and organic acids (1) control, (2) 50 mg P kg-1, (3 and 4) 50 mmol kg-1 of organic acids (oxalic and malic acids), (5) P + oxalic acid and, (6) tomato fruit residue (25% w). After 10 weeks, plants were harvested and the parameters such as plant height, fresh and dry weights, phosphorus concentration and its uptake were determined. Results and Discussion Results indicated that soil type effect was statistically significant on the plant fresh and dry weights (P≤ 0.05), height, concentration and uptake of P (P≤ 0.01), respectively. Results also showed that the tomato fruit residue treatment in comparison with P fertilizer and malic acid treatments results in a significant increase in P taken up, and fresh and dry weights (P≤ 0.05). There was a significant difference between P fertilizer + oxalic acid and oxalic acid alone treatments in only plant height (P≤ 0.05). Also, no significant differences in terms of measured plant parameters were observed between malic acid and blank treatments (P≤ 0.05). Conclusion Application of tomato fruit residue rather than P fertilizer can help to take up residual soil P, to grow plants and to decrease of environmental pollution, and to be also affordable economically.
Soil Biology, Biochemistry and Biotechnology
M. Soliemanzadeh; H. Khademi; M. Sepehri
Volume 37, Issue 2 , March 2015, , Pages 59-72
Abstract
Microorganisms play an important role in providing nutrients for plants and also in soil development. This study was carried out to investigate the effect of two strains of Bacillus cereus on the release of potassium and iron from micaceous minerals. An experiment was set up with a completely randomized ...
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Microorganisms play an important role in providing nutrients for plants and also in soil development. This study was carried out to investigate the effect of two strains of Bacillus cereus on the release of potassium and iron from micaceous minerals. An experiment was set up with a completely randomized design and factorial arrangement with three replications. Treatments included two types of mineral (phlogopite and muscovite), two strains of bacteria (PTCC 1247 and PTCC 1665), control and eight time periods. The results indicated that released potassium and iron were highly dependent on the strain of bacterium and also the mineral type. Strain PTCC 1665 could release a higher amount of potassium as compared to PTCC 1247. The amount of released iron increased at the beginning of the experiment but decreased and then increased as time passed. In general, the amount of released iron from phlogopite was higher than that from muscovite.
Soil Biology, Biochemistry and Biotechnology
A.R. Fallah Nosratabad; S. Momeni; S. Shariati
Volume 37, Issue 2 , March 2015, , Pages 73-86
Abstract
The present investigation was designed to compare the effect of combination biofertilizer of nitrogen fixing free-living bacteria and plant growth promoting bacteria of Azotobacter. It also aimed to compare the effect of Azospirillum alone and in combination with other plant growth promoting bacteria ...
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The present investigation was designed to compare the effect of combination biofertilizer of nitrogen fixing free-living bacteria and plant growth promoting bacteria of Azotobacter. It also aimed to compare the effect of Azospirillum alone and in combination with other plant growth promoting bacteria of Pseudomonas fluorescens and Bacillus subtilis with five nitrogen fertilizer levels on the wheat growth indices and yield.The experiment including biofertilizer and different amounts of nitrogen fertilizer was carried out as factorial in completely randomized design with three replications. At the end of plant growth period, some plant indices such as spike and grain number, crop yield, grain to straw weight ratio, straw yield, and grain nitrogen percentage were measured. The results showed that in the simple effect of bio fertilizer, the most effective factor was related to the biofertilizer consortium containing Azotobacter, Azosprillum, Pseudomonas and Baillus subtilis which respectively increased 8, 22.5, 26.5 and 23.3 % the amounts of grain nitrogen, spike number, straw yield and plant yield in comparison with control treatment. Although in the simple effect of chemical fertilizer on studied indices, 100 kg/ha of nitrogen had the most effect, it didn’t demonstrate any significant difference in comparison with the fertilizer level of 75 kg/ha. The highest amounts of measured indices were related to the interaction of bio fertilizer including Azotobacter, Azosprillum, and Pseudomonas and Bacillus subtilis with nitrogen level of 75kg/ha that could respectively increase 25, 100.4, 53.5, 100.6 and 92.6% of grain and spike number, the nitrogen content of grain, straw and plant yield compared to control plant.
Plant Nutrition, Soil Fertility and Fertilizers
G. Roshani; A. Gharanjiki
Volume 37, Issue 2 , March 2015, , Pages 87-99
Abstract
The fertility maps are useful tools to know about the land resources. These maps are essential to do a correct fertilizer recommendation, monitoring the changes of soil fertility level and also to do prediction of toxicity or deficiency of necessary plants nutritional elements in the soil. The present ...
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The fertility maps are useful tools to know about the land resources. These maps are essential to do a correct fertilizer recommendation, monitoring the changes of soil fertility level and also to do prediction of toxicity or deficiency of necessary plants nutritional elements in the soil. The present research was carried out to digital mapping of macro and micro elements as well as some important physical and chemical properties of the soil for agricultural service centers of Golestan province to optimize the use of chemical fertilizers in operating plan pattern. The studied areas were under irrigated and rain-fed wheat cultivation and the total surface area was about 520000 hectares. Using based maps with the scale of 1: 50,000, the area was divided into 5200 grids each having one kilometer square area. Using Global Positioning System (GPS) instrument a composite soil sample was taken from the center of any grid and analyzed for major macro- and micronutrients as well as physical and chemical properties of the soil namely; pH, EC,TNV, sand, silt and clay contents. At the time of sampling, some additional information like latitude, longitude, elevation, owner's name, date of sampling, kind of water resources, possibility of water logging, crop history (present and previous) was collected and recorded. After getting the laboratory results, for the above stated data sets, an electronic layer was created for any particular parameter and after doing interpolation, the layers were polygonized. Anisotropy of the data sets in different directions was evaluated by the help of variogram surface operation. Then spatial correlation of each data set was calculated. After variogram analysis, spatial variation of the data sets was studied and a suitable model was selected. Finally, through point interpolation using kriging technique, the digital map of each parameter was established.
Soil Biology, Biochemistry and Biotechnology
S. Shariati; H. Alikhani; A. Pourbabaei; F. Shariati
Volume 37, Issue 1 , September 2014, , Pages 93-107
Abstract
In order to determine the effect of plant growth promoting bacteria Pseudomonas fluorescens on yield and nutrient availability in corn some special materials like mesoporous silica nanoparticles, vermicompost, bentonite and a mixture of all were inoculated by the bacteria and preserved for six months. ...
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In order to determine the effect of plant growth promoting bacteria Pseudomonas fluorescens on yield and nutrient availability in corn some special materials like mesoporous silica nanoparticles, vermicompost, bentonite and a mixture of all were inoculated by the bacteria and preserved for six months. Soil and seeds were treated by the inoculants. The experiment was set up in a randomized complete block design with three replications. The treatments comprised of three inoculants and two fertilizers including diammonium phosphate, single super phosphate and control (without any phosphorus fertilizer). After 60 days of corn emergence, some plant growth indices and the concentration of some elements in plant shoots were measured. The results demonstrated that Pseudomonas fluorescens inoculant significantly increased phosphorus shoot content, total yield and chlorophyll by 74, 46 and 22.1%, respectively compared to the control treatment (P<0.05), but it did not show any significant difference with phosphorus fertilizer treatments (P>0.05). The vermicompost inoculants could significantly (P<0.05) increase zinc and iron contents of shoots by 114 and 53.6%, respectively in comparison to the control treatment. Orthogonal comparisons of the two methods of seed and soil inoculation showed the efficiency of seed inoculation on shoot phosphorus at 5% level, but no significant difference was observed between these two methods for other measured characteristics (P>0.05).
