Ali Rezaei; Mohammadtaghi Ebadi; Hassan Pirani
Abstract
Introduction: Organic production is one of the important aspects in the medicinal plants industry and the use of organic fertilizers is very important in this topic. Seaweeds are important marine living resources with tremendous commercial applications and many commercial products from seaweed extract ...
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Introduction: Organic production is one of the important aspects in the medicinal plants industry and the use of organic fertilizers is very important in this topic. Seaweeds are important marine living resources with tremendous commercial applications and many commercial products from seaweed extract are used in agriculture and horticulture. Seaweed extracts can be used in liquid form as a foliar spray, soil drench or in powder and granular forms as soil conditioners and manure. Using seaweed extracts as fertilizers can improve plant productivity, because they contain growth-promoting hormones. Several studies have also shown that the seaweed extracts can suppress plant diseases and insect pests. Nowadays, seaweed extract is used as an organic fertilizer in order to increase the quantitative yield of medicinal plants and also resistance to environmental stresses. Summer savory is one of the medicinal and spice plants that has a high area under cultivation in our country for food and medicine. Various studies on its essential oil had been shown that it contains high amounts of phenolic compounds like Carvacrol, γ-Terpinene, Thymol, p-Cymene, β-Caryophyllene, Linalool, and other terpenoids.
Materials and Methods: In order to study the effect of different levels of seaweed fertilizer on the growth characteristics, plant material yield, essential oil percentage of summer savory, an experiment was conducted as a randomized complete block design with 3 replications at the Faculty of Agriculture, Tarbiat Modares University (TMU) during 2017. The treatments included: 0 (control), 2.5, 5 and 10 ml/liter seaweed fertilizer that they were used as a foliar application for three times in the growing season. According to the meteorological data, the area had an average rainfall of 246 mm and a semi-arid climate. In order to determine the physical and chemical properties of the soil, soil sampling and testing were done. To prepare the field, the soil tillage operation was carried out using a 40 cm depth plow. Then, plots with a 2 × 2 meters at a distance of half a meter from each other were prepared. The seeds used in this experiment were prepared from Varamin landrace, which is mainly cultivated by farmers in Tehran and Alborz provinces. Sowing operation was carried out manually. In each plot, 7 rows (30 cm spacing between rows) were cultivated and all of the plots were irrigated in the same conditions. The organic fertilizer (Bioalgax) used in this experiment was based on an extract of seaweed (Ascophyllum nodosum), which was obtained from the Kimitec company, Spain. This fertilizer is a natural source of phytohormones such as cytokinins, auxins, and gibberellins and also, it has some minerals. After reaching the height of 20 cm (eight weeks after planting), spraying of the fertilizer solutions was applied three times during the growing season at intervals of 10 days. The foliar application was carried out at sunset time by using a manual sprayer. The harvest was carried out at full flowering stage and 3 plants of each plot were harvested. The studied traits were: plant height, stem diameter, the number of branches, leaf length, and width, shoot fresh and dry weight, root fresh and dry weight, SPAD index, essential oil yield and content.
Results and Discussion: The results showed that different concentrations of seaweed fertilizer had a significant effect on the number of branches, shoot dry weight, root fresh and dry weight, leaf width and plant height at 1% probability level. They also had a significant effect on the shoot fresh weight, essential oil percentage, and yield at 5% probability level. On the basis of the results, the highest number of branches (35.44), leaf length and width (43.22 and 8.07 mm), stem diameter (5.00 mm), root fresh and dry weight (15.17 and 6.42 g), shoot fresh and dry weight (181.01 and 37.69 g) and SPAD index (48.13) were obtained from 10 ml/liter seaweed fertilizer and the lowest amounts were observed in control treatment. The maximum plant height (54.66 cm) and the highest percentages and the yield of essential oil (2.51% and 6.28 g/m2) were also obtained from 5 ml/liter seaweed fertilizer. According to the results, the response of summer savory to the use of seaweed fertilizer was positive and it could be placed in the fertilization program of farmers.
Hossein Sabourifard; Azim Ghaesmnezhad; Khodayar Hemmati; Aboutaleb Hezarjaribi; Mahmoodreza Bahrami; Fahimeh Nosrati
Abstract
Introduction: One of the most important requirements in planning production and processing of medicinal plants in order to obtain high yield and high-quality is the initial assessment of the physical and chemical properties of soil, which reduces the production cost by avoiding the use of unnecessary ...
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Introduction: One of the most important requirements in planning production and processing of medicinal plants in order to obtain high yield and high-quality is the initial assessment of the physical and chemical properties of soil, which reduces the production cost by avoiding the use of unnecessary soil analysis. Summer savory (Satureja hortensis L.) is one the most widely used medicinal plants that quality index of plant is related to the quantity and the constituent of its essential oil content. Understanding the relations between the quantity and quality of medicinal plants with the very physical and chemical properties of soil is very complex and the estimation of parameters changes of medicinal plants affect by soil quality characteristics is more difficult. Today, with the arrival of multivariable regression models and artificial lattice models in the research, many complex relationships found in nature is understandable. Hence the need for estimation the biomass yield of savory using fast, cheap and with acceptable accuracy is feeling.
Materials and Methods: The present study was performed at the Agricultural Research Station Neyshabur as pot experiment based on a completely randomized design with three replications. Around 53 soil samples were collected from different parts of Neyshabur city, and soil texture, organic matter, pH, salinity, phosphorus, potassium, nitrogen and carbon content were selected as the easily available parameters. Before planting the parameters were measured in laboratory. Approximately 90 days after planting seeds in pots containing soil samples, the sampling of plants was done based on the treatments. For drying, samples were placed for 24 hours in an oven at 40 °C. Finally, the relationship between the biomass yield and easily available soil parameters was determined using artificial neural network by Matlab7.9 software.
Results and Discussion: The results showed that soil variability, is a key element in the management of valuable information on soil properties within a field and valuable information on soil properties within a field nature puts at our disposal. In yield modeling with 10 parameters for 53 soil samples, the best makeup hidden layer with Levenberg-Marquardt algorithm training as a hidden layer, 58 neurons, logsig threshold function for hidden layer and Tansig for the output layer were selected. High values of R2 and low levels of RMSE mentioned the proximity of the forecast data with measurement data and high accuracy of the model in summer savory biomass yield estimation. To obtain the most sensitive parameters, the sensitivity analysis was calculated using no-sensitive coefficient. So that, if the coefficient of a sensitive parameter is more than 1.0, the mentioned parameter, is one of the critical parameters of model. Accordingly, the parameters of organic carbon, nitrogen, phosphorus, organic matter, potassium, pH, salinity, clay, silt and sand respectively were selected as the most sensitive parameters. The addition of input parameters increases the value of R2 and reduces the RMSE during training, validation and test stages. This represents an increasing in the accuracy of model in estimation of biomass yield via increasing the input parameters. Models 1(soil texture) and 2(carbon) are not enough strong for biomass yield estimation. With increasing the experiment from 1 to 2, the potency of the neural network model 3(soil texture + carbon) significantly increased. Thus with an overview, the model No. 3 suggested as an improved model because with the minimum number of imputes produced equal output comparing the models with more inputs.
Conclusions: Based on the obtained results, it seems that with the improvement of artificial neural network models and determining appropriate parameters, results to understanding the soil factors involved in the formation of savory plant biomass and better planning. Till leads to a cheaper and better product. Also, results showed that the artificial neural network has high accuracy in estimating the biomass plant Summer Savory. So that, the 80% of yield variability of the study area, presents by using the data of 10 readily available properties of the soil. Yield biomass of savory, largely depends on the soil texture, organic matter, carbon and the minerals of the soil. Since, this study is the first work to estimate the biomass of medicinal plants using artificial neural network, therefore recommended to use this method to estimate the yield and essential oil of other medicinal plants.
