A. Rahimi; B. Doulati; S. Heydarzadeh
Abstract
Introduction Lamiaceae, formerly called Labiatae, the mint family of flowering plants with 236 genera and more than 7,000 species, the largest family of the order Lamiales and many species are cultivated for their fragrant leaves and attractive flowers. Thymus daenensis is native to Iran and growing ...
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Introduction Lamiaceae, formerly called Labiatae, the mint family of flowering plants with 236 genera and more than 7,000 species, the largest family of the order Lamiales and many species are cultivated for their fragrant leaves and attractive flowers. Thymus daenensis is native to Iran and growing in many parts of Iran, the plant is extensively used in folk medicine and has a wide variety of essential oils. Medicinal and aromatic plants have antioxidant compounds such as polyphenols which decrease oxidative stress in cells of plants and animals. In recent decades, excessive use of chemical fertilizers in order to increase the yield of agricultural products has caused many problems in economic and environmental aspects. The biofertilizer plays an important role in nitrogen fixation, iron sequestration, and phosphate solubilization, thus making these complex organic molecules available for utilization by the plants. Biofertilizers are the microbial inoculants that colonize the rhizosphere and improve plant growth by enhancing nutrient accessibility to plants. However, biofertilizers perform more than one mechanism for accomplishing plant growth enhancement. These abilities are of great agriculture importance as far as crop yield and soil fertility improvement is concerned, thus decreasing the ill effects of chemical-based fertilizers in our environment. For instance, excessive use of chemical N fertilizers causes soil acidifcation and, thus, groundwater and atmospheric pollution. Nonetheless, synthesis of chemical fertilizers is highly energy-consuming processes. Chemical based fertilizers impose long-lasting effects on the atmosphere in terms of carbon footprint, eutrophication, and soil fertility decline. However, the control of chemical and biological properties of soil is important in the quantity and quality of agricultural crops. Few reports reveal that in case of controlled soil conditions, signifcant enhancement in crop production was achieved through biofertilizer applications. Thus, this research was carried out with the aim of studying the effect of independent and combined use of biological and chemical fertilizers on quantitative and qualitative properties of thyme. Materials and Methods The aim of this study was to investigate the effect of biofertilizers (phosphate Barvar-2 and Azotobacter), manure (cow manure), and chemical (NPK) on quantitative and qualitative characteristics of Thymus daenensis. Physicochemical properties of study soil (calcium carbonate equilibrium, pH, OC, EC, micro and macro elements, soil texture) and was determined by standard methods. A factorial experiment based on randomized completely design was carried out with eight treatments including chemical fertilizer (100%), biofertilizers (phosphate Barow-2 and Azotobacter) (100%), cow manure (100%), combined treatment: chemical + biofertilizer 50%, chemical + cow manure 50%, biofertilizer,+ cow manure 50%, biofertilizer + chemical + cow manure 50% and control at three replications. Seeds of Thymus daenensis were treated before cultivate with biofertilizers (phosphate Barvar-2 and Azotobacter) with 100 g ha-1 based on the recommended guidelines (10^8 active bacteria g-1 of biofertilizer). Seeds were cultured in perlite and pit moss culture beds. Transplant was transmitted to the farm at the end of April. Thymus product was harvested at flowering stage. Economic performance of thymus including leaf and inflorescence weight was calculated after drying of bushes. Essential oil content was measured using clevenger. Physiological and antioxidant propertiese including chlorophyll a and b, total chlorophyll, cartenoids, total phenolic content and flavnoieds were measured (Lichtenthaler and Wellburn, 1987; Horwist, 1984). Essential oil yield was obtained from essential oil percentage in dry matter yield of thymus. Results The results showed that the integrated application of biofertiliizers was significant in qualitative and quantitative characteristics of Thymus daenensis. Based on the results, shoot dry yield (156.26 g m-2), essential oil yield (5.36 g m-2) and economic yield (74.72 g m-2) in 50% chemical fertilizer + biofertilizer + cow manure treatment were higher as compared to other treatments. Integrated application of organic and chemical fertilizers improved the content of photosynthetic pigmentation and increased the concentration of iron (Fe), zinc (Zn) and copper (Cu) in thymus. Aso, combined application of 50% chemical fertilizer + biofertilizer + manure increased total phenol (30.12%), flavonoids (22.26%) and antioxidant activity (15.95%) of thymus compared to control treatment. Conclusion The results showed that the chemical fertilizers to start production and compensate for the fertilizer source and biofertilizers for the continuous of the presence of nutrients in soil are important. Consequently, the combination of chemical fertilizer (NPK) and biofertilizers could be recommended as a suitable nutrition source for plant as well as the improvement of soil physical and chemical properties. Accordingly, chemical fertilizers consumption are hazardous for human severely affect ecological balance in the environment. Therefore, the success related to biofertilizers depends on inventions of innovative strategies which are related to the functions of different beneficial bacteria and their proper application to the fields through advanced and improved techniques.
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.