Agricultural Engineering

Research Paper Soil, Water and Plant Relationships

Estimation yield and water use efficiency of tomato using spectroscopy under deficit irrigation regimes and Silica nanoparticle in greenhouse conditions

Anahita Hadighanavat; Abdolrahim hooshmand; Parvaneh Tishehzan; Naser Alemzadeh ansari,; Kazem Rangzan

Volume 47, Issue 4 , December 2024, Pages 445-466

https://doi.org/10.22055/agen.2024.47342.1736

Abstract

Introduction Nowadays, the management of water resources has become one of the major challenges in the world due to recent droughts and water shortages. Therefore, timely and non-destructive monitoring of Water use efficiency (WUE) and yield of plants to screen cultivars with high water use performance ... Read More Introduction Nowadays, the management of water resources has become one of the major challenges in the world due to recent droughts and water shortages. Therefore, timely and non-destructive monitoring of Water use efficiency (WUE) and yield of plants to screen cultivars with high water use performance and efficiency and rational allocation of water has become one of the important goals in agriculture. Compared with traditional crop Yield and WUE monitoring and diagnostic tools, hyperspectral remote sensing technology has made it possible to obtain water use efficiency and Yield by taking advantage of large amounts of continuous data on a large scale. Therefore, this study aimed to create a model capable of estimating the WUE and Yield of tomato plants based on hyperspectral remote sensing data by establishing a relationship between common spectral indices and WUE and Yield in greenhouse conditions.Materials and Methods The research was carried out during the growing season of 2021 from January to June at the research greenhouse of the Department of Water and Environmental Engineering, Shahid Chamran University, Ahvaz, Khuzestan Province, The main factor was irrigation treatments in three levels including full irrigation, 20%, and 40% deficit irrigation, and the sub-main factor was silica nanoparticles with concentrations of 0 and 100 mg/lit. The pot experiment plot was laid out in a split plot in a randomized complete design (RCD) with four replications (120 pots in total). Then Tomato yield and WUE under the various treatments, were calculated. Canopy hyperspectral reflectance was measured using a portable spectrometer (ASD FieldSpec 3) operated in the spectral range of 350-2500 nm. The spectral data acquisition was conducted in four stages of plant growth during the growing season and the data were used to calculate spectral indices NWI5, WI3, WI4, NDVI, NDVI, and OSAVI. Then the ability of spectral indices to evaluate the water use efficiency and yield of tomato plants in different irrigation regimes and nanoparticles was investigated. Analysis of variance (ANOVA) was performed on spectral indices and WUE and yield of tomato plants using a split plot design. The PROC GLM method of SAS software (version 9.4, SAS Institute, Inc., Cary, NC, USA) was used for this analysis. Then, in order to compare the averages and whether they have a significant difference with each other at the 0.01 and 0.05 levels, the least significant difference (LSD) test was used.Results and Discussion The results showed that the Water use efficiency (WUE) under deficit irrigation treatments is increased with increasing water stress but the yield of tomato decreases with increase of water stress. In addition, the WUE and yield of tomato increases with increasing the concentration of silica nanoparticles (from 0 to 100 mg/liter). The value of NDVI and OSAVI indices decreased with the increase of water stress, while the value of RDVI, WI3, WI4 and NWI5 indices increased. The amount of NDVI and OSAVI spectral indices in the treatment containing 100 mg/liter nanoparticles was higher than the treatment without nanoparticles. Also, the amount of spectral indices RDVI, WI3, WI4 and NWI5 in nanoparticles with a concentration of 100 mg/liter was lower than the control treatment (zero concentration). The results also showed that the coefficient of determination between the different spectral indices and the WUE and Yield index was 0.55**Furthermore, among the six spectral indices, three spectral indices (NWI5, WI3, and WI4) jointly met most of the criteria used to determine the accuracy of the models for predicting yield and WUEConclusion Maintaining existing water resources through improving irrigation management and increasing water use efficiency and Yield of plants is the main goal for the sustainable development of water agriculture. As a result, rapid and non-destructive monitoring of water use efficiency and Yield is of great importance in improving irrigation management of crops and saving water consumption. significant relationship with yield and WUE index of tomato plants in greenhouse conditions. In conclusion, Spectral indices studied in this research could be useful and non-destructive assessments of the water use efficiency and yield of tomato in greenhouse conditions.Keywords: Deficit Irrigation, Spectral indices, spectroscopy, Tomato Plant, Water use efficiency

Research Paper Plant Nutrition, Soil Fertility and Fertilizers

Effect of co-application of zinc enriched biochar and foliar application of zinc on some physiological traits and the zinc uptake in wheat (Triticum aestivum L.)

Narges Sousaraei; Mojtaba Barani Motlagh; Seyed Alireza Movahedi Naeini

Volume 47, Issue 4 , December 2024, Pages 467-490

https://doi.org/10.22055/agen.2024.46559.1719

Abstract

Introduction: When the supply of micronutrients needed by the plant is insufficient, not only the yield of the product but also the quality of plant products are affected. Application of organic amendments is one of the ways to increase the nutrients such as zinc uptake by plants for. Biochar can be ... Read More Introduction: When the supply of micronutrients needed by the plant is insufficient, not only the yield of the product but also the quality of plant products are affected. Application of organic amendments is one of the ways to increase the nutrients such as zinc uptake by plants for. Biochar can be used as a raw material for the preparation and synthesis of mineral or metal composites due to its high specific surface area, porous structure and oxygen bonding groups on its surface. In these composites, biochar is used as a good porous structure to support and host metals. Biochar can have a significant impact on soil properties, the availability of nutrients, and the dynamics of the nutrients in arid and semi-arid soils, Depending on the feedstock and pyrolysis conditions However, very limited studies have examined biochar use as a nutrient carrier in the synthesis of organic-mineral compounds. Therefore, the present study was done to investigate the efficiency of zinc-enriched biochar pellets using two pre-pyrolysis and post- pyrolysis methods, and their effect on some physiological traits (chlorophyll a, b and total) and bioavailability of zinc in soil and plant.Methods and Materials A zinc deficiency Soil was collected from 0-30 cm depth under arable lands of Seyed Abad located in Azadshahr township, Golestan Province, Iran. To achieve the objectives of this study, a factorial experiment in a completely randomized design with three replications and 18 treatments (54 pots in total) was performed in the greenhouse of Gorgan University of Agricultural Sciences and Natural Resources. Factors included three types of zinc fertilizers (zinc sulphate, zinc-rich biochar prepared using pre-pyrolysis and post-pyrolysis methods) in three levels (0, 10 and 20 mg kg-1 zinc) and foliar spraying (distilled water and 3:1000 zinc). Zinc foliar spraying was done during the 6-10 leaf stage in the early hours of the morning before sunrise. Irrigation and weeding operations were performed manually. At the end of the growing period (vegetative and reproductive), some physiological traits (chlorophyll a, b, total and carotenoid), concentration and zinc uptake in shoots in the two stages of flag leaf emergence and seed maturity, and available concentration of zinc in the soil after wheat plant harvest were measured. The statistical results of the data were analyzed using SAS software and LSD test (at 5% level) was used for comparing the mean values.Results and Discussion: Based on the results, the interaction of type and levels of treatments was significant on all the studied traits at P<0.01, except for carotenoid. The means comparison showed that both zinc-enriched biochar pellets and zinc sulfate increased physiological traits in wheat plants. The highest amount of chlorophyll a, b, and total was obtained with an average of 4.99, 3.36, and 8.35 mg g-1 of fresh weight of the plant from the treatment of a pre-pyrolysis pellet with a concentration of 20 mg kg-1 with zinc sulfate foliar spraying, respectively. The highest zinc uptake in both the flag leaf emergence and seed maturity stages was obtained with an average of 120.33 and 86.62 mg kg-1 of dry weight of the plant from the pre and post-pyrolysis pellet treatment with a concentration of 20 mg/kkg with zinc sulfate foliar spraying, which had an increase of 20 mg kg-1 of zinc sulfate foliar spraying, respectively, equivalent to 27.69 and 30%. The pre-pyrolysis pellet treatment with 20 mg kg-1 zinc and zinc sulfate foliar spraying gave the most zinc extracted with DTPA, at an average of 3.41 mg kg-1. This was compared to the 10 mg kg-1 and 0 mg kg-1 pre-pyrolysis biochar pellet treatments, which gave an average of 2.39 mg kg-1 and 0.92 mg kg-1, respectively, which is an increase of 29.91 and 73.02 percent. The amount of DTPA extractable Zn with the amount of chlorophyll a (r = 0.87**), chlorophyll b (r = 0.81**), total chlorophyll (r = 0.87**), and carotenoids (r = 0.89**) had a positive and significant correlation. The results showed that between DTPA extractable Zn with zinc concentration (r = 0.91**) and zinc uptake (r = 0.90**) in the stage of flag emergence and zinc concentration (r = 0.87**) and zinc uptake (r = 0.86**) in the stage of seed maturity in the wheat plant, there was a positive and significant correlation.Conclusions: In general, the results showed that the positive role of biochar-zinc pellets in increasing the concentration and zinc uptake in wheat plants. Nevertheless, supplemental zinc foliar application with biochar pellets rich in zinc in the amount of 20 mg kg-1 in the form of post-pyrolysis had the greatest effect on the physiological characteristics and Zn bioavailability for wheat plants.

Analytical and Applicable Papers Plant Nutrition, Soil Fertility and Fertilizers

Seasonal changes in nutrients of three date (Phoenix dactylifera L.) varieties in Ahvaz weather conditions

Fatemeh Foroozesh fard; Shohreh Zivdar; Esmaeil Khaleghi; Edris Shabani

Volume 47, Issue 4 , December 2024, Pages 491-510

https://doi.org/10.22055/agen.2024.47849.1741

Abstract

Background and Objective: One of the important aspects of nutrition physiology in fruit trees is the study of seasonal changes in leaf elements, because the seasonal pattern of absorption and distribution of nutrient elements is very important in estimating the fertilizer requirement of fruit orchards. ... Read More Background and Objective: One of the important aspects of nutrition physiology in fruit trees is the study of seasonal changes in leaf elements, because the seasonal pattern of absorption and distribution of nutrient elements is very important in estimating the fertilizer requirement of fruit orchards. The movement of nutrients in fruit crops has been reported a lot, and the plants' need for a specific element is influenced by a specific growth stage in the plant. Research has shown that nutrient accumulation occurs as a continuous process throughout the growing season. In plants, the change process of elements is different in the seasons. By examining the dynamics of elements during different seasons and having the necessary information about these changes, it is possible to examine the relationship between the demand for nutrients during the periods of vegetative and reproductive growth.In Iran, many research has been done on the nutritional requirements of different commercial fruit cultivars, and many studies have reported the dynamics of nutrients in fruit trees during the growing season, but in the case of dates, despite the relative diversity Regarding the cultivars of this plant and Iran's presence in the international competitive markets, there was no report on measuring the dynamics of nutrient elements during the seasons. In the upcoming research, the seasonal evaluation of the concentration of some macronutrients and micronutrients in the leaves of three date varieties has been done.This study was carried out in order to evaluate the seasonal changes in nutrients in the leaves of three date varieties.Materials and Methods: This experiment was conducted in the date palm research garden in the northern part of Shahid Chamran University of Ahvaz, in a randomized complete block design with four replications, during 2022 on the leaves of ten years old date palm cultivars (Berhi, Estamaran, and Zahedi). In this experiment, the trend of seasonal changes in macro nutrients (nitrogen, phosphorus, potassium and calcium) and micro nutrients (iron, copper, boron, zinc and manganese) concentration, were investigated throughout the four seasons.After collecting the data, the data was statistically analyzed using SAS 9.1 statistical software, and Duncan's test was used to compare the average data at the level of one and five percent.Results: The results showed that the seasons have a significant effect on the concentration of the elements except nitrogen and manganese. Also, the interaction of season and cultivar had a significant effect on the concentration of all nutrients. In terms of macronutrients, Berhi had a better condition, especially during the growing season (spring and summer). The highest difference in terms of element concentration was observed between the winter and growth seasons for date cultivars. The minimum concentration of nitrogen (0.94%) was for Zahedi in spring and winter and the maximum concentration was 2.01% for Barhi (winter). Phosphorus concentration was recorded from the lowest (0.13%) in winter and spring to the highest (0.36%) in summer for Barhi. The range of potassium changes ranged from 1.01% (Estamaran, autumn) to 1.18% (Zahedi, winter). The seasonal changes in calcium concentration was recorded between 0.76 and 0.92%. Also, the range of changes in iron concentration during the year was from 65 to 130 mg/kg and during the growing season to mid-summer from 87 to 117 mg/kg. Bades on the results, leaf iron concentration was estimated to be less than optimal in all seasons. Also the concentration of nitrogen, potassium and copper in leaves decreased during the growth season, especially in summer, and can be due to the consumption of these elements for reproductive growth.Conclusion: The concentration of minerals in plants depends on the interaction of several factors including soil, plant species, climate, growth stages, plant production and management and the interaction of elements during absorption. The successful growth of plants and trees requires suitable soil and the presence of sufficient amounts of usable elements and the relationship between them, among which nitrogen, phosphorus and potassium elements are among the main essential elements required by the plant.The results showed that there is a significant seasonal variation in macronutrients and micronutrients in three date varieties. Also, different seasonal changes patterns were observed among cultivars regarding elements. In such a way, potassium and calcium are more stable than nitrogen and phosphorus during different seasons of the year. Macronutrients (phosphorus and calcium) and micronutrients (zinc, boron and manganese) were at the optimal level. But, the amount of nitrogen, potassium, iron and copper was evaluated as less than the optimal level, which suggests the use of fertilizers containing the mentioned elements at the end of winter..

Applicable Plant Nutrition, Soil Fertility and Fertilizers

Improving the nutritional management and yield of Ricinus communis L. using Arbuscular mycorrhizal fungus and organic fertilizers

Hadi Ahmadian; Shiva Khalesro; Gholamreza Heidari

Volume 47, Issue 4 , December 2024, Pages 511-531

https://doi.org/10.22055/agen.2024.46395.1716

Abstract

Introduction: A decline in soil organic matter is a key facet of soil degradation, leading to the loss of soil fertility and the capacity to produce crops. The intensive use of synthetic inorganic inputs, such as chemical fertilizers, has resulted in soil organic matter depletion, groundwater contamination, ... Read More Introduction: A decline in soil organic matter is a key facet of soil degradation, leading to the loss of soil fertility and the capacity to produce crops. The intensive use of synthetic inorganic inputs, such as chemical fertilizers, has resulted in soil organic matter depletion, groundwater contamination, air pollution, and reduced production quality in arid and semi-arid regions. Therefore, sustainable techniques, such as organic fertilizers and natural inputs, are becoming increasingly important to enhance soil organic matter and plant yield in sustainable agricultural systems. The use of organic fertilizers and soil amendment like biochar and wood vinegar can significantly improve soil organic matter. Much of the world's interest in biochar stems from the worsening condition of agricultural soils and the depletion of water resources. Additionally, biochar has attracted researchers’ interest mainly due to its long-term soil carbon sequestration potential, role in greenhouse gas mitigation, phytoremediation, and ability to improve soil fertility. Biochar and wood vinegar can be made from various biomass materials/residues such as wood waste, crop and refinery residues, animal manures, and municipal wastes. Biofertilizers also play a vital role in sustainable agriculture systems. Mycorrhiza is one of the most important biofertilizers. Mycorrhizal associations help plants obtain water and nutrients in dry and nutrient-poor conditions by increasing the root surface area for water and nutrient uptake. Castor bean (Ricinus commonis L.) is a valuable annual herb belonging to the Euphorbiaceae family. It is an important oilseed crop widely used in industry and medicine today. Numerous studies have underlined the beneficial effects of organic fertilizers on soil fertility and crop yield. However, no study has evaluated the impact of organic fertilizer, biochar, wood vinegar, and mycorrhiza on Ricinus commonis L. This research aims to discover the main effects and interactions of these treatments on the quantitative and qualitative traits of Ricinus commonis L.Materials and Methods: The field experiment was conducted at the Research Field at the University of Kurdistan (35° 19' N, 47° 18' E) during 2022 growing season. The research was designed as a factorial experiment using a randomized complete block design with three replications. Treatment included five fertilizer types: control, organic fertilizer (800 kg ha-1), biochar (3000 kg ha-1), wood vinegar (90 kg ha-1) and chemical fertilizer (urea 200 kg ha-1, and TSP 100 kg ha-1). Additionally, two mycorrhiza levels (Rhizophagus irregularis) were tested: no-inoculation and inoculation. Each experimental plot consisted of six rows, each 6 meters long and spaced 75 cm apart. The seeds were sown on 10 May 2020. Agronomic traits such as plant height, number of capsules per plant, and 1000-seed weight were randomly measured from five plants at full maturity in each plot. In the center rows of each plot, 2.25 m2 of area was harvested at the end of each growing season to evaluate biological and seed yield. Other studied traits included harvest index, seed oil content, seed oil yield, and the nitrogen, phosphorous, and potassium concentration of the seeds.Results and Discussion: The results showed that the effect of mycorrhiza inoculation on the plant height, capsules number per plant, seed number per plant, and 1000-seed weight was significant. Furthermore, the fertilizer impact on the mentioned traits except of 1000-seed weight was significant. Organic fertilizer, biochar, wood vinegar, and chemical fertilizer significantly increased the capsules number per plant. The highest number of capsules per plant and seed number per plant belonged to the organic fertilizer. Mycorrhiza inoculation enhanced the seed number per plant and 1000-seed weight by 16% and 23% compared to control, respectively. the interaction effects of different fertilizers and mycorrhiza inoculation improved the quantitative and qualitative traits of castor bean. The highest biological yield (3650.2 g/m2), seed oil content (50.5 %), and oil yield (588.3 g/m2) were observed in the integrated treatment of organic fertilizer and mycorrhiza inoculation. This treatment increased seed and biological yield by 36.5% and 24% compared to control, respectively. Mycorrhiza can enhance plant growth and yield by increasing the supply of phosphorus to the host plant. Mycorrhizal plants can absorb and accumulate several times more phosphate from the soil or solution than non-mycorrhizal plants. Organic fertilizer and biochar positively affected the morphological characteristics. Biochar reduces water consumption and improves soil properties under drought conditions. Compared to other amendment materials, biochar has the benefit of a large surface area and pore spaces, allowing it to absorb and retain water. The highest seed nitrogen and potassium content was observed in the organic fertilizer treatment. Organic fertilizers may promote root development by retaining more water and nutrients in the soil, secreting more plant hormones, and increasing the amount of inorganic material such as nitrogen, phosphorus, and potassium that plants can absorb.Conclusion: Therefore, it can be said that the integrated application of organic and biofertilizers not only improve the quantitative and qualitative traits of Ricinus commonis L. but also could be a key strategy in sustainable agricultural systems by reducing the consumption of chemical fertilizers.

Applicable Agricultural Machinery

Design, Manufacture, and Evaluation of Blades for a Rotary- Trencher Machine

Arash Khoshabari; Seyed reza Mousavi Seyedi; Sajad Kiani

Volume 47, Issue 4 , December 2024, Pages 533-549

https://doi.org/10.22055/agen.2024.47767.1739

Abstract

Introduction Two-wheeled tractors are used to disturb the topsoil in greenhouses and small gardens. These machines consist of a rotating shaft connected to a gearbox, on which a set of flanges is mounted. Blades are attached to each flange in a specific arrangement. When the flanges rotate, they come ... Read More Introduction Two-wheeled tractors are used to disturb the topsoil in greenhouses and small gardens. These machines consist of a rotating shaft connected to a gearbox, on which a set of flanges is mounted. Blades are attached to each flange in a specific arrangement. When the flanges rotate, they come into contact with the soil, lifting and throwing it backward, thus breaking up the soil and creating a suitable seedbed for planting agricultural products. A transmission system transfers the necessary and generated force from an engine to the blades for soil cutting. Notable features of these machines include reasonable prices, high operational speed, easy mobility due to lightness, and simple maintenance and repair. Rotary cultivators or rotary soil mixers are also used to prepare the soil bed and control weeds in fruit orchards. In this research, the most suitable blade for producing a double-purpose rotary-trencher machine equipped with a V-shaped gearbox was designed and produced.Materials and Methods Catia software (V5-6R2018) was used for the design and Abaqus software (6.14-4) was used for mechanical analysis of the designed blades. First, the blades were designed with three different surfaces 42.75, 38.53, and 35.39 cm2. The goal was to achieve a blade design that not only creates a suitable tilled soil surface but also maximizes soil displacement to ensure the device performs acceptably during furrow creation. The blade stress analysis was performed based on the Von Mises criterion and finite element analysis (FEA). After the design of the blades, to ensure their strength against the forces exerted from the soil surface, FEA and examination of the mechanical strength of the selected alloy (ST52) were performed in Abaqus software. Then, the blade spread design was cut using a CNC machine, forged using a blacksmithing mold, and bent with a 38-millimeter radius. After this stage, the surface of the blades was hardened. The evaluation of the device in the disturbing of the topsoil with three blade models at three blade shaft speeds (200, 300, and 400 rpm) was performed in three repetitions in the form of a factorial experiment in a completely randomized design using SPSS software. The disturbing of the topsoil and the depth of the created trench were considered as criteria for evaluating the rotation speed and dimensions of the blades.Results and Discussion The maximum force applied to blades showed that the maximum stress obtained with surfaces of 42.75 cm2, 38.53 cm2, and 35.39 cm2, based on the Von Mises criterion, was 0.74, 0.7, and 0.188 MPa, respectively. Also, the maximum principal stress in these three blade models was 0.27, 0.24, and 0.122 MPa, respectively. The results illustrated that the maximum stresses obtained are much lower than the yield stress or ultimate strength of the alloy used in the blade. To do the topsoil tillage operation 6 flanges of blades (18 blades) and to do trenching two flanges of blades (6 blades) were installed on the axis of the gearbox. The results from comparing Mean Weight Diameter (MWD) values of the disturbed topsoil showed that by increasing rotation of the blade shaft, the soil disturbing significantly increases. On the other hand, results showed that the increase in the surface of the blade was not significant in disturbing the topsoil particles. Also, the blades were evaluated by creating a trench. Two flanges of the blades (6 blades, Fig 1. b) are performed when the machine moves backward (Fig 9-a and Fig 11). The machine's reverse speed was kept constant at 2 km/h. The results clearly showed that the surface of the blades has had a significant effect on the performance of creating a trench, and with the increase of the blade's surface, the amount of soil transferred out of the trench has increased. However, increasing the blade surface increased the trench depth, but increasing the blade's axis rotation was not as significant as the blade surface because the backward speed of the machine is constant and slow.Conclusion In this research, a new type of blade for a dual-purpose rotary-trencher machine was designed, analyzed, produced, and evaluated. The results of the statistical analysis showed that the blade's surface has no effect on the tillage quality, but the rotation speed of the blades was significantly effective. On the other hand, in the operation of creating a trench, the surface of the blade was significantly effective, and with the increase of the surface, the depth of the created trench increased due to the movement of more soil particles. Finally, a blade with a surface of 42.75 cm2, made of ST52 alloy steel, with a forged and hardened edge, and a bending radius of 38 mm was proposed for this type of dual-purpose soil rotary-trencher machine. Therefore, this machine equipped with the designed blade model is suitable for both topsoil disturbing and trencher.

Applicable Post Harvesting Technology

Investigating factors affecting the density, strength and durability of pellets made from olive processing plant waste

Reza Tabatabaeekoloor; shaban ghavami jolandan

Volume 47, Issue 4 , December 2024, Pages 551-564

https://doi.org/10.22055/agen.2024.48055.1744

Abstract

Introduction Fuel pellets are one of the uses of biomass, which are made from agricultural waste, plant residue, and animal excrement. They produce more energy per unit volume. Various factors are effective in the pelleting process. Having information about them helps to optimize the pelleting process ... Read More Introduction Fuel pellets are one of the uses of biomass, which are made from agricultural waste, plant residue, and animal excrement. They produce more energy per unit volume. Various factors are effective in the pelleting process. Having information about them helps to optimize the pelleting process and to understand the compression mechanism and the design of compacting equipment. Materials and Methods Olive pomace raw material for making pellets was obtained from an olive processing factory in Rudbar city in Gilan province. The prepared materials were transferred to the laboratory in the necessary amount in nylon bags and dried in the oven at 105 degrees Celsius for 24 hours. The dried samples were powdered by a laboratory grinder and then passed through sieves in the range of 0.6-1.5 mm and used to make pellets. Before making pellets, the initial moisture content of the samples was obtained using the drying method. First, pre-tests were conducted to make pellets and the moldability and strength of the samples were checked. A palletization mechanism was used to compress the pellet. This system was designed and built in biosystem mechanics of Sari University of Agricultural Sciences and Natural Resources. The material was placed inside a steel mold with a cylinder inner diameter of 8.05 mm and a height of 150 mm with a blocked end. A piston with a diameter of 8 mm connected to the driving arm of the tension-compression test machine was used to compress the material. Loading by a piston with a quasi-static speed of 6 mm per minute is compressed. In this research, the effect of particle size treatments (600-900, 900-1200 and 1200-1500 μm), compaction pressure (75, 150 and 225 MPa) and temperature (50, 70 and 90 ͦC) on the density, strength and durability of the pellet were investigated.Results and Discussion The results indicated that the main effects of all three mentioned treatments on the strength, density and durability of the pellet are significant. Also, the mutual effects of some treatments are also significant on these characteristics. The interaction effect of particle size and compaction pressure on pellet compressive strength is significant at 5% level. With the increase in particle size, the pellet strength increased first, and then with the further increase in particle size, the pellet strength decreased slightly. On the other hand, with the increase in compression pressure, the pellet resistance increased. Pellet density is an important factor for storage and transportation as well as combustion efficiency. The mutual effect of compression pressure and particle size on pellet density is significant. Changes in pellet density were obtained in the range of 1.015 to 1.350 grams per cubic centimeter. The usual and recommended density for pellets made from agricultural and forest residues should be more than 0.8 grams per cubic centimeter. The interaction effect of compaction pressure and temperature on pellet durability is significant. The range of durability changes for pellets is between 81 and 95 percent. Increasing compaction pressure significantly improved the stability of the pellets, which indicates the role of compaction in bonding between particles and creating bridges for greater particle strength. The highest pellet strength was obtained in the combination of particle size of 900-1200 micrometers, temperature of 90 degrees Celsius and compaction pressure of 225 MPa. The highest density was obtained at a particle size of 600-900 and a compression pressure of 225 MPa and the best stability at a compression pressure of 150 MPa and a temperature of 90 degrees Celsius. In general, the physical and mechanical properties of the pellet were affected by all three factors: particle size, temperature and compaction pressure.Conclusion The results of this research showed that all three factors of particle size, compaction pressure and temperature have a significant effect on the physical and mechanical properties of pellets such as density, strength and durability. Choosing the right particle size plays an important role in making the pellet stronger. The temperature of the die during pelleting is also very important in the bonding of the pellet particles because at the right temperature, the bonding between the bridges strengthens the connection of the particles and as a result increases the strength and durability of the pellet. In general, the results of the research showed that to make pellets from olive processing factory waste, a suitable combination of particle size parameters, compaction pressure and die temperature is needed to make pellets with high strength and durability.

Applicable Agricultural mechanization

Presenting a schedule model for annual Massey Ferguson 399 tractors maintenance using GERT method, A case study: Dehkhoda Sugarcane Agro-industry Company

Mehdi Anafche; nasim monjezi

Volume 47, Issue 4 , December 2024, Pages 565-584

https://doi.org/10.22055/agen.2024.47154.1733

Abstract

Introduction Considering the high use of agricultural machines in sugarcane Agro-industry company; management of maintenance and repairs is necessary. The application of agricultural mechanization and the management of machines in agriculture is responsible for improving the way of working and correct ... Read More Introduction Considering the high use of agricultural machines in sugarcane Agro-industry company; management of maintenance and repairs is necessary. The application of agricultural mechanization and the management of machines in agriculture is responsible for improving the way of working and correct use of machines. Today, with the mechanization of agricultural systems, the timely performance of activities requires correct machine planning. For proper planning, one must know the reliability of the machines. Increasing efficiency and reliability of machines is an economic necessity. Any scheduled program to increase the reliability of machines can be effective in reducing time loss due to repairs and cause repairs to be completed on time. Therefore, in this research, according to the nature of the project of annual repairs of MF 399 tractors, in which the activities and the time of their completion are possible, the graphic evaluation and review technique (GRET) method was used. GERT's method is one of the possible network programming methods. In GERT's method, the occurrence of activities is considered possible and a percentage of probability is assigned for the occurrence of each activity.Materials and Methods This research was conducted in the Dehkhoda Sugarcane Agro-industry Company in the crop year of 2023-2024. Dehkhoda Sugarcane Agro-industry Company has 42 Messi Ferguson 399 double differential tractors. In this research, in order to schedule annual repairs, statistics and data related to the repairs of 22 MF 399 tractors were collected and the data of other machines were used to compare the actual repair time with the calculated schedule. The 13 repair items of MF 399 tractors used in the company include: engine, clutch, gearbox, differential and rear axle, brake, rear hub, body, front axle, hydraulics, electricity and battery, wheels, service and greasing. The work breakdown structure diagram and network model of annual MF 399 tractor repairs were drawn. To extract the time distribution density function of each activity, first the available information was collected for each activity, then the time distribution density function was determined for each activity. The time to perform the activities is fuzzy and they are expressed by triangular fuzzy numbers. In this research, after scheduling, the results obtained from GERT's method were compared with the actual time spent to perform annual MF 399 tractor repairs and the appropriateness of the estimates was determined. For this purpose, in order to determine the actual time of annual MF 399 tractor repairs, among the tractors available in the mechanical equipment department of Dehkhoda Sugarcane Agro-industry Company, in the crop year 2023-2024, a sample was randomly selected and the actual duration of repairs was determined. Then the actual time to complete the operation was compared with the expected time.Results and Discussion The time to complete the annual repairs of MF 399 tractors was estimated to be 225.93 hours using the classic GERT method. But in GERT's Fuzzy method, the time calculated for annual MF 399 tractor repairs was (295.30, 232.07, 168.73) hours. The actual duration of annual repairs for 20 tractors (out of a total of 42 tractors) in Dehkhoda Sugarcane Agro-industry Company, which were repaired during the 2023-2024 crop year, according to the information available in the technical office of the company's mechanical equipment, was determined. 29.12% of the real times for completing MF 399 tractor repairs were estimated outside the fuzzy time. Therefore, the manager of the repair unit can reduce the cost of time loss and manage the time to complete the operation in the optimal time frame by using correct planning and reducing the reasons for the delay in the operation.Conclusion Therefore, GERT F Fuzzy's method provides the possibility to the manager of the repair unit to set the completion time in the estimated range appropriately, taking into account other effective factors involved in the operation, so that there is no disruption in the implementation of activities and on the other hand, the costs to minimize when the work is not done. It also provides the possibility to create cuts at different times and control the operation process and modify it if needed. In the real world, due to existing uncertainties, there is not enough confidence in the duration of the annual maintenance of tractors, but nevertheless, the results obtained from GERT's method in this research are close to the actual time of completion of operations and make the estimates more appropriate.

Applicable Soil Genesis and Classification

Modelling and Digitally Mapping of Surface Soil Organic Carbon in Semirom County Employing Several Machine Learning Algorithms

Fatemeh Rahmati; ُSaeid Hojati; Kazem Rngzan; Ahmad Landi

Volume 47, Issue 4 , December 2024, Pages 585-605

https://doi.org/10.22055/agen.2024.47815.1740

Abstract

Introduction: Knowledge about the spatial distribution of soil organic carbon (SOC) is one of the practical tools in determining sustainable land management strategies. Estimation of carbon contents and stocks are important for carbon sequestration, greenhouse gas emissions and national carbon balance ... Read More Introduction: Knowledge about the spatial distribution of soil organic carbon (SOC) is one of the practical tools in determining sustainable land management strategies. Estimation of carbon contents and stocks are important for carbon sequestration, greenhouse gas emissions and national carbon balance inventories. Accurate mapping of SOC’s spatial distribution is a key assumption for soil resource management and land use planning. During the last two decades, the utilization of data mining approaches in spatial modeling of SOC using machine learning algorithms have been widely taken into consideration. The digital environment needs to have soil continuous maps at local and regional scales. However, such information is always not available at the required scale. Therefore, DSM approach is a key solution for quantifying and assessing the variation of soil properties such as SOC using remotely sensed indices and digital elevation model (DEM) as the most commonly useful ancillary data for soil organic carbon prediction. In this way, the data mining techniques is the pathway to create digital soil maps. Therefore, this study was carried out to compare the two common machine learning algorithms including random forest and multiple linear regressions in digital mapping of surface SOC in the Semirom County, Isfahan province. The digital maps of SOC using the two above-mentioned algorithms were also created and the most important variables affecting the distribution of SOC in the study area reported. Materials and Methods: A total number of 200 surface soil samples (0-10 cm) were collected from the Semirom area (51º 17' - 52º 3' E; 30º 42' - 31º 51' N), Isfahan, Iran. Based on the synoptic meteorological station reports, the annual average temperature was in the range of 7.5-12.5 ▫C, the annual precipitation ranged between 350-450 mm. Soil moisture and temperature regimes are Xeric and Mesic, respectively. Then, using the Global Positioning System (GPS), sampling was done from the soil surface layer (0-10 cm). The preparation of soil samples includes air drying, pounding and softening of the collected samples performed, and then the samples were passed through a 2 mm sieve. Then, the amount of organic carbon in the samples was determined utilizing the Walkley-Black method. Also, in order to evaluate the effect of other soil properties on the organic contents of the soils, laboratory analyzes including saturated soil moisture content, soil texture, soil pH in saturated pastes, electrical conductivity of the soil saturation extracts and the calcium carbonate equivalent of the soils were measured utilizing standard laboratory protocols.In this research, auxiliary variables including terrain parameters and vegetation indices were derived from digital elevation model (DEM) and the Landsat 8 OLI satellite images employing ArcMap version 10.4.10 and SAGAGIS version 6.0.4. Then, all auxiliary layers were converted to raster format using the “raster” package and merged with each other using the “Covstack” function. Afterwards, the values of the all environmental covariates at each sampling point were extracted in a single file using the “extract” function of the “sp” package in the RStudio environment. Then, using SPSS software v.19 and the principal component analysis (PCA) method, among the 29 auxiliary variables used in this research, the most important auxiliary covariates were used in the modeling process. The dataset were then split into two groups referred to as calibration (80%) and validation (20%) subsets. Finally, SOC contents of the soils were predicted and mapped using multiple linear regression (MLR) and random forest (RF) algorithms in RStudio environment. MLR and RF algorithms were run employing “lm” and “randomForest” packages, respectively. Five different statistics was used for evaluating the performance of each model including the coefficient of determination (R2), bias, root mean square error (RMSE), nRMSE, and mean bias error (MBE). Results and Discussion Based on the descriptive analysis of the soil samples, soils of the study area were characterized as non-saline, alkaline, and calcareous soils. The SOC contents of the soils ranged from 0.3 % to 2.2% with the mean value of 0.89 %. The coefficient of variation for the SOC contents was 21.7%, based on which soils of the study area are classified as soils with the moderate variability considering the values proposed by Wilding (1985). The results of PCA showed that the most important auxiliary variables could be used for the modeling process are slope aspect, channels network base level, catchment slope, total curvature, height, longitudinal curvature, mass balance index, modified catchment area, slope degree, slope length, topographic position index, vertical distance to channel network, soil adjusted vegetation index, transformed vegetation index, difference vegetation index, ratio vegetation index, and general curvature.These variables explained 80% of the total variance over the study area. The comparison of the two different SOC prediction models, demonstrated that the RF model (ntree =1000 and mtry =10) with the R2, RMSE, nRMSE, and bias values of 0.79, 0.12, 0.13, and 0.002 respectively, had a better performance rather than MLR model in this study. The first five very important variables detected by RF algorithm to predict SOC contents over the study area were transformed vegetation index, ration vegetation index, soil adjusted vegetation index, and slope degree. The final map of the surface SOC distribution over the study area shows that although the estimates made by the RF algorithm have provided better estimates compared with the MLR model, but caused overestimation and/or underestimation in predicting the minimum and maximum values of the surface SOC contents, respectively. Conclusion The results of this study showed the better performance of the RF regression algorithm due to its ability to take into account the nonlinear and complex relationships between SOC contents and the environmental covariates compared to the MLR method.

Effect of Tillage and Planting Methods in Hill Slopes on Soil Erosion and Wheat Grain Yield under Rain Fed Conditions in Kermanshah Province

Volume 35, Issue 2 , March 2012, , Pages 1-12

Abstract

The erosion in dryland causes decrease in yield and soil quality, especially in slope lands with conventional tillage. To investigate the effects of tillage and planting methods in slope lands on erosion and yield of rain fed wheat, an experiment was conducted in 2007-2008 at Kermanshah Province. The ... Read More

Ergonomic Evaluation of the Posture of Dates Packinghouse Workers by REBA Method

Volume 37, Issue 1 , September 2014, , Pages 13-22

Abstract

This study was conducted among dates’ packinghouse workers with the objectives of a) determining of MSDs prevalence and b) evaluating level of exposure to MSDs risk factors. The results of this study can be used to develop MSDs preventive strategies in the workplace and improve workers’ health. ... Read More

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Application of gypsum and manure on improving the amount of nitrogen, phosphorus and potassium in leaves and seeds of wheat under salinity stress

Volume 36, Issue 1 , September 2013, , Pages 1-11

Abstract

Salinity limited plant growth and will decrease the yield with decrease in solution osmotic pressure, nutrient imbalance and toxicity of some specific elements. Application of amendment materials such as gypsum and cattle manure can adjust the undesirable effects and increase the nutrient elements in ... Read More

The Effects of Different Sizes of Particles of a Superabsorbent Polymer on Water Holding Capacity of Two Different Soil Textures

Volume 36, Issue 1 , September 2013, , Pages 65-75

Abstract

Superabsorbent polymers are water containers that absorb and retain large quantities of water when applied to the soil. These materials release the absorbed water, allowing the plants to consume adequate amounts of water at all growth stages. One of the best options for increasing the irrigation efficiency ... Read More

Estimating Soil Erosion and Sedimentation Using Cesium-137 Method: A Case Study (Raymaleh Watershed, Lorestan)

Volume 35, Issue 2 , March 2012, , Pages 37-54

Abstract

The rate of soil erosion and sediment yield estimation in the catchment areas is considered as an important factor for soil and water conservation practices. Due to difficulties and restrictions in common soil erosion methods, applying a high accuracy method with lowest cost and time consuming would ... Read More

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Evaluation of the nutrient content of soil and wheat grain due to the integrated application of chemical and organic fertilizers

Ali Reza Jafarnejadi; Farhad Moshiri; Fatemeh Meskini-Vishkaee

Articles in Press, Accepted Manuscript, Available Online from 21 December 2024

https://doi.org/10.22055/agen.2024.48100.1746

Abstract

Introduction: Arid and semi-arid areas such as Khuzestan province has highly fragile ecosystems that are characterized by low soil fertility, and high organic matter decomposition rates. Moreover, according to the FAO, around 12% of world soils and 65% of Iran's soils are calcareous and more than 20 ... Read More Introduction: Arid and semi-arid areas such as Khuzestan province has highly fragile ecosystems that are characterized by low soil fertility, and high organic matter decomposition rates. Moreover, according to the FAO, around 12% of world soils and 65% of Iran's soils are calcareous and more than 20 % of the irrigated farms in the world is affected by salinity. Since soil carbon saturation is low in saline-calcareous soils, the use of organic manure can be effective in increasing soil organic carbon and supplying essential nutrients in crop production. Applying organic manure in agriculture has been considered during the last two decades due to its high-quality products, high price, and low market availability of synthetic fertilizers, chiefly in developing countries. The manure application, both alone or in combination with inorganic fertilizers, is effective in increasing soil organic carbon (SOC) content and improve in soil fertility, microbial activity, and soil water retention capacity. Now the integrated application of organic and chemical fertilizers is inevitable for sustainable production and soil conservation. Hence, comprehension of the response of the soil and crop to applying organic and inorganic fertilizer may help to determine proper manure management strategies to enhance SOC and improve soil health and its ecosystem services. Thus, the aim of the study was to investigate the effects of different fertilizer managements on nutrient content of soil and wheat in saline-calcareous soils of Khuzestan province.Materials and Methods: To evaluate the effect of the integrated and long-term application of chemical and organic fertilizers on the nutrient content of soil and wheat grain in fixed plots, this research was carried out in Khuzestan province (Ahvaz city) in a calcareous- saline soil with silty clay texture under wheat cultivation (Barat cultivar) as a randomized complete block design in six treatments with three replications for four years (2017-2021). The treatments included T1: unfertilized control, T2: application of nitrogenous, phosphorus and potassium chemical fertilizers based on soil test, T3: application of 20 tons of cattle manure every two years + 75% of recommended nitrogen + 50% of the recommended phosphorus and potassium, T4: application 20 tons of bagasse every two years + 75% of the recommended nitrogen + 50% of the recommended phosphorus and potassium, T5: annual application of 20 tons of cattle manure + 75% of the recommended nitrogen, T6: annual application of 20 tons of bagasse + 75% of the recommended nitrogen. In treatment T2 recommended dose of P2O5, K2O, and 30 % of recommended N were applied at the time of second irrigation; the remaining N dose was applied in two splits at tillering (40 % of recommended N) and booting stages (30 % of recommended N). The organic manures were incorporated in the soil (depth 0-15 cm) a week before sowing. At the end of the growing season, wheat yield components were measured. At the end of the growth season, some soil properties involved pH, salinity and SOC, and the concentration of nitrogen, phosphorous and potassium in soil and grain wheat were determined. SAS v.9.1 statistical software and LSD test were used to compare the means of the studied treatments.Results and Discussion: The mean values of SOC varied in range of 0.60 to 0.73 %. As a result of applying treatment T2 (inorganic fertilizers application as alone), no significant difference was observed in SOC compared to the control treatment (p< 0.05). Compared to unfertilized control treatment, the SOC content were increased significantly by the use of cattle manure at T3 treatment (0.13 %), which could be attributed to the larger proportion of tenacious organic compounds in organic fertilizers than in chemical fertilizer. The highest concentration of soil available phosphorus (19.8 mg kg-1) was obtained in the integrated application of chemical fertilizer and cattle manure (T3), which is 60 and 169 % higher than those in the exclusive chemical fertilizer application (12.35 mg kg-1) and control (7.35 mg kg-1) treatments, respectively. The highest average soil available potassium concentration (253.3 mg kg-1) was also observed in T3. The results showed that the application of different fertilizer treatments was significant only on the nitrogen concentration of wheat grain (p< 0.01). The increase in wheat grain nitrogen concentration due to the application of integrated fertilizer treatments (28-38% increase compared to the control treatment) was significantly higher than the chemical fertilizers treatment (19% increase compared to the control treatment).Conclusion: Based on the results of this research, it was found that the integrated application of organic and inorganic fertilizers has a more positive effect on improving soil fertility in the long term than using them alone. Moreover, the results indicated that the use of cattle manure was more effective than bagasse manure which may be due to its lower carbon to nitrogen ratio (21.3). The integrated use of organic and inorganic fertilizers not only improve soil fertility, but also increases the efficiency of chemical fertilizer use, which reduces the basic chemical fertilizers consumption. Therefore, it is recommended to application of 20 tons of cattle manure every two years + 75% of recommended nitrogen + 50% of the recommended phosphorus and potassium (T3) in the saline-calcareous soils under wheat cultivation in arid and semi-arid climates such as southern of Khuzestan province.

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Investigating the temporal changes in some soil quality properties in different tillage management in agricultural lands of western Golestan province

Bahareh Kiani; Farshad Kiani; Azam Rezaee; Pouneh Ebrahimi; Samaneh Mahzari

Articles in Press, Accepted Manuscript, Available Online from 29 December 2024

https://doi.org/10.22055/agen.2024.48218.1748

Abstract

Introduction: Different strategies have been proposed to sustainable soil management, including conservation agriculture. Conservation agriculture is based on four principles. Reducing plowing and soil disturbance, leaving an appropriate amount of plant residues on the soil surface, crop rotation with ... Read More Introduction: Different strategies have been proposed to sustainable soil management, including conservation agriculture. Conservation agriculture is based on four principles. Reducing plowing and soil disturbance, leaving an appropriate amount of plant residues on the soil surface, crop rotation with an economic cultivation pattern, and sustainable production of agricultural products with benefits are the basis of these four principles. The economic benefits of conservation agriculture and tillage in the early years have challenges in terms of implementation. There are few studies on the impact of the initial phase of conservation agriculture on soil nutrients and its consequences, so this study aims at the impact of Various protection management on some soil quality indicators during the initial years of implementation. Recently, farmers in Golestan province have been following the conservation agriculture in their fields without implementing a standard method and uniform instructions. Therefore, different results are obtained by implementing conservation tillage methods. In general, the economic benefits of conservation agriculture in the first year of its implementation are very controversial, and farmers think that the implementation of conservation agriculture may not be profitable due to the high consumption of herbicides and low yield, especially in the early years of its implementation.Methods and Materials: This study was conducted in Nokandeh region of Golestan province in the form of a randomized complete block experiment in three types of management including optional(minimum) tillage (MT), Conservation agriculture (CA) and conventional tillage (CT) and in 4 years. In each management, 30 soil samples were selected from the depth of 0 to 20 cm and the indicators were evaluated. Soil pH, Texture, Electrical Conductivity, Total Neutralizing Value (TNV), Soil Carbon, Total Nitrogen, Available Phosphorus and Potassium, and soil micronutrients contain Fe, Mn and Zn were evaluated using scientific methods. Data normality was also tested using the Kolmogorov-Smirnov test. The difference between the means has been calculated using Duncan's test at the confidence level of 0.01 and 0.05. SAS ver 9.4 software was used to analyze the data.Results and Discussion: he results show that the effect of tillage management on pH changes is not significant, while the effect of time on pH changes is significant at the one percent level (p ≤ 0.01). The pH in no-till in the fourth year was (7.64) and minimum tillage (7.62) and conventional tillage (7.4). The lowest pH value was in conventional tillage treatment, which decreased by 3.6 percent compared to the first year. The main decrease in electrical conductivity was observed in no-till, with a 32% decrease in soil electrical conductivity in the fourth year compared to the first year, and the minimum changes were observed in conventional tillage. The amount of organic soil in conservation agriculture and then OC was observed to increase by 47% and 17%, respectively, compared to the first year. The implementation of conservation management in different years was not significant on the amount of TNV, but the percentage of the amount of TNV was observed in tillage managements, CT > CA > CT respectively. The amount of total nitrogen has increased in MT and CA, which means a decrease in nitrogen leaching in four years. Conservation agriculture in the fourth year can increase the amount of available phosphorus in the soil by 47% compared to the first year, and the potassium element has increased by 58% in CA and 52% in MT, while the potassium content has increased by 6%. The elements of iron and zinc in MT and the amount of manganese in CA were higher. The results of the present study showed that the most important management factors affecting the initial years are the amount of soil organic matter. Soil nutrients are sensitive indicators of fertility. Changes in soil nutrients increase with a gentle slope in the initial years. And this trend is sometimes accompanied by uncertainties. There are significant aspects of water, plant, and soil interactions in nutrient cycling, etc., that are still unknown.Conclusion: The results of this study showed that although low tillage and no-till treatments improve soil nutritional and fertility indices compared to conventional tillage, the trend of changes in these indices over time is different, which may discourage farmers and promoters in the early years of implementation. Considering that different results have been obtained in this research, it seems that to achieve better and visible results by farmers, sufficient time is needed for implementation. These findings provide a practical perspective to farmers, promoters and managers to realistically pay attention to the achievements in the early years of implementation. It is suggested that in the initial years of implementation in farms with greater fragility and uncertainty, government support should be provided to reach the final sustainability of the plan.

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Assessment and modeling of soil quality using multivariate analysis approach (Case study of rainfed agricultural land in Dezpart city)

Sina Bigdeli; Heidar Ghafari; Mojtaba Norouzi Masir; Abdolamir Moezzi

Articles in Press, Accepted Manuscript, Available Online from 01 January 2025

https://doi.org/10.22055/agen.2025.48357.1753

Abstract

Introduction: Today, the concept of soil quality (SQ) has been widely used to know the capacity and limitations of soils in different environmental systems. The degree of suitability of land is determined by its capacity to provide services and its flexibility against external conditions. Production ... Read More Introduction: Today, the concept of soil quality (SQ) has been widely used to know the capacity and limitations of soils in different environmental systems. The degree of suitability of land is determined by its capacity to provide services and its flexibility against external conditions. Production of plant biomass is one of the most important functions of soil in relation to food security. The share of dry land in Iran's agricultural production, especially wheat, is very significant. So that in terms of area, about half of the total area of agricultural lands, in terms of volume of production, about 10% of all agricultural products and about 30% of the country's wheat production are related to these lands. Therefore, maintaining the soil quality of these lands is very important. The main goal of this research is to model and quantify the soil quality of part of the rainfed agricultural lands of Dezpart city using integrated multivariate analysis and also to determine the minimum effective data set.Materials and methods: This study was carried out in a part of the rainfed agricultural area of Dezpart County. First, 119 soil samples were prepared using the composite method from the soil depth of 0-30 cm. Soil sampling was done in a stratified random manner to include all the different geomorphological units. The geographic location of the sampling points was also recorded. The samples were transferred to the laboratory and their chemical-fertility and physical characteristics include reaction (pH), electrical conductivity (EC), organic matter (OM), total nitrogen, available potassium, absorbable phosphorus, calcium carbonate equivalent (CCE), texture, bulk density, mean weight diameter (MWD) of soil aggregates, soil gravel content and cation exchange capacity (CEC) were measured. Then the soil quality was determined using two datasets of total (TDS) and minimum (MDS), and multivariate analysis method. In this method, by using appropriate scoring functions, a score between zero and one was considered for each member of the data set. Also, a weight coefficient was calculated for each member, and finally, the soil quality index, which indicates its degree of desirability, was obtained by three indices including Nemero (NQI), cumulative weighted index (IQI) and simple cumulative index (AQI). Finally, a spatial variation map of soil quality was prepared using the Inverse Distance Weighting (IDW) method in geographic information system (GIS) software.Results and Discussion: The results of the principal component analysis (PCA) test indicated that there are three main components that cover 78% of the total variance changes. The first component alone accounts for about 41% and the second and third components account for 25% and 12% of the total data variance, respectively. Based on the correlation analysis between soil components and characteristics, five characteristics including organic matter (OM), silt content, gravel, pH and EC were selected as MDS members. Became in the TDS collection, the highest weights related to silt and sand (0.093 and 0.095, respectively) and the lowest weight with 0.050 was assigned to bulk density (BD). In the MDS set, the highest weight was related to organic matter and silt and the lowest weight was related to pH. The soil quality of the region was generally classified as medium based on the two indexes of AQI and WQI. However, the NQI method indicated that the soil quality was low. Among the three selected indices with different functions and data sets, the weighted soil quality index with the minimum data set and nonlinear function (WQI_MDS_NL) was chosen as the superior model due to having a higher sensitivity index (or a larger standard deviation). The spatial soil quality map, which was prepared for this study, showed that approximately 50% of the lands in the region had an average soil quality and 50% had a low soil quality.Conclusion: Organic matter, silt, pH, gravel and EC are the main characteristics to determine the soil quality of the region. In addition, stability of soil aggregates, bulk density and lime are the most important limiting factors of soil quality in the region. Therefore, it is suggested to use appropriate management practices such as conservation tillage and use of organic fertilizers to improve these characteristics.

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Effect of Carbon Black and Zinc-Solubilizing Bacteria on the Chemical Distribution of Zinc in Soil under Salinity Stress

Sepideh Raeisi; Nafiseh Rangzan; Naeimeh Enayatizamir

Articles in Press, Accepted Manuscript, Available Online from 11 January 2025

https://doi.org/10.22055/agen.2025.48339.1752

Abstract

Introduction: Zinc (Zn) is a vital nutrient for plants, needed in small amounts for their reproductive and physiological functions. Zinc deficiency is common in soils with high pH, low organic matter, and high calcium carbonate. Soil salinity is one of the most important and common environmental stresses ... Read More Introduction: Zinc (Zn) is a vital nutrient for plants, needed in small amounts for their reproductive and physiological functions. Zinc deficiency is common in soils with high pH, low organic matter, and high calcium carbonate. Soil salinity is one of the most important and common environmental stresses in the world. The impact of salinity on the forms of zinc and its availability in soil has varied. Among the chemical forms of zinc, the soluble and exchangeable forms have the highest mobility and availability for plants; whereas the residual form, associated with the crystalline lattice of soil minerals, appears to be very inactive. Depending on the physical and chemical properties of the soil, the carbonate forms, those bound to iron and manganese oxides, and the organic forms of elements are relatively active and have the potential to be available for plants. Organic materials like carbon black can alter zinc distribution. Zinc-solubilizing bacteria enhance zinc availability by converting insoluble forms into absorbable ones. This study examines the effects of carbon black and growth-promoting bacteria on zinc forms and soil properties under varying salinity levels.Materials and Methods: In this study, to investigate the effect of carbon black and inoculation of a mixture of two bacteria on the distribution of chemical forms of zinc under salinity stress, a pot experiment with four replications was conducted as factorial with three factors: salinity (2, 5, and 8 dS m-1), carbon black (0, 4% by weight), and a mixture of two bacteria (inoculated and non-inoculated). The bacteria included Enterobacter cloacae and Bacillus sp., which were obtained from the microbial collection of the Soil Science Department at Shahid Chamran University of Ahvaz. The experiment was carried out in a completely randomized design in 2023 in the greenhouse of Khuzestan Agricultural Sciences and Natural Resources University. In 5-kilogram pots, 10 corn seeds were planted, which were reduced to 6 plants per pot after ensuring germination. Two months after planting, soil samples were taken from the pots, and after removing the roots and passing through a 2-millimeter sieve, they were transferred to the laboratory to determine the chemical forms of zinc. The sequential extraction method was used to determine the chemical forms of zinc. The fractions—exchangeable, carbonate, iron and manganese oxides, organic, and residual—were determined. The concentration of zinc in the extracts obtained from the various stages of sequential extraction of the soil was read using an atomic absorption device. Some biological properties of soil, such as microbial biomass carbon via fumigation-extraction method, catalase activity via the titration method, and soil respiration by titration of residual NaOH, were measured.Results and Discussion: The interaction effect of carbon black× inoculation× salinity on chemical forms of Zn was significant. The results showed that the inoculation of a mixture of two bacteria and addition of carbon black in soil significantly increased the soluble and exchangeable, carbonate, iron and manganese oxide, and organic forms of zinc. Inoculation of a mixture of two bacteria and carbon black to the soil at a salinity level of 2 dSm-1 resulted in an increase in EXCH-zinc from 1.02 to 1.38 mgkg-1 compared to the control, which is equivalent to a 35% increase. Inoculation of the bacterial mixture and the addition of carbon black to the soil increased all forms of zinc except the residual form. With increasing salinity level, the amounts of soluble and exchangeable, carbonate-bound, and oxide-bound forms increased, while the organic-bound form decreased. The highest amounts of microbial biomass carbon, catalase activity, and soil respiration were measured in the treatment with bacteria, carbon black, and at a salinity level of 2 dS m-1, with values of 19.9 mg-Cmic 100g-1, 0.95 mLKMnO4g-1h-1, and 70.2 mgCO2 100g-1day-1, respectively. There was a positive correlation between soil respiration and all forms of zinc, except the residual form, but the correlation between soil respiration and the residual form of zinc was negative, indicating the influence of microbial activity on different forms of zinc.Conclusion: The addition of a carbon black to the soil and inoculation of a mixture of two bacteria caused zinc to convert from residual form to soluble and exchangeable, carbonate, oxide, and organic forms, increasing the availability of zinc in accessible fractions at various salinity levels. Overall, zinc-solubilizing bacteria offer a promising solution for enhancing zinc availability in saline soils, promoting plant health, and contributing to sustainable agricultural practices.

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Investigating the use of Reflectometry and surface soil color for separation of surfaces exposed to gully erosion

Mitra Yarahmadi; Ataallah Khademalrasoul; hadi Amerikhah

Articles in Press, Accepted Manuscript, Available Online from 11 January 2025

https://doi.org/10.22055/agen.2025.48065.1745

Abstract

Introduction: Soil erosion is the most prevailing form of soil degradation which is really play an important role on the mass balance index of soil particles in the watersheds. Moreover, regarding the on-site and off-site effects of erosion essentially has to measure and predict the soil loss using different ... Read More Introduction: Soil erosion is the most prevailing form of soil degradation which is really play an important role on the mass balance index of soil particles in the watersheds. Moreover, regarding the on-site and off-site effects of erosion essentially has to measure and predict the soil loss using different methods. Specifically gully erosion is a form of water erosion with the huge amount of soil dislodgement. Due to the complexity and variability of soil erosion it is necessary to apply different techniques in order to monitor the soil erosion changes. Remote sensing technology and the use of spectrometry and reflectometry basics is a suitable solution and option for monitoring coastal areas affected by erosion and deposition events, which provide high quality temporal and spatial data. Soil color is an appearance property which is meaningfully effective on soil reflectance. Generally, soils with high amount of organic matter has low reflectance because of the darkness while the light soils has high reflectance from surface (high Brightness index, BI) which is effective on soil temperature. Therefore we try to use RS and radio spectrophotometry to find a relation between soil color and its reflectance. Materials and Methods: The study area is located at Zahirieh watershed of Khuzestan province which is between Ahvaz and Masjedsoleyman cities with approximately 7100ha area. The average of rainfall is 218.6mm, the maximum temperature is 54 and the minimum is 7 degrees. Regarding the separation of erosional and depositional surfaces in the study area; first, using the visual inspection of Landsat satellite false color images, 8 regions were divided into several regions, then random sampling points were created using the random point generator tool in ArcGIS 10.4 software to implement the random sampling method within the block. Finally, 12 sampling points representing erosion surfaces and 14 sampling points representing depositional surfaces were selected and sampled to determine surface soil characteristics. Surface soil color was determined using Mansell's color book in natural daylight in two dry and moist conditions. After collecting the soil samples in air-dry moisture condition and also in wet condition, their spectroscopic analysis was done by FieldSpec3 device and this moisture condition was considered for all the soil samples of eroded and depositional surfaces. Statistical analyzes and mean comparisons were performed using SPSS 26 statistical software. Corrections of satellite images and transformations were made in ENVI 4.7 software, and visual outputs and maps were made in ArcGIS 10.4 software.Results and Discussion: Results depicted that among the evaluated soil color indicators, the dry weight parameter is significant at the level of 1%. This level of significance shows well that the Value index in the dry state can be used as an effective parameter to identify and separate erosion and deposition levels in the study area. There is a difference between the values of the statistics for red, green and blue RGB in the dry state for erosion and depositional surfaces, and these differences are also evident for the moist state. In the depositional surfaces, with the drying of the soil, blue, red, and green reflections all decrease, but this decrease is double and about six times for blue. The reduction of blue reflections in the RGB system leads to an increase in the yellowness of the color. In the case of the soils of erosion surfaces, we can see the pattern of the photo and we see the enhancement of reflections and consequently the lightening of the color of the soil when the soil is dry. According to what has been seen in the Munsell system, it seems that this issue has a direct relationship with the amount of organic matter and the ratio of fulvic acid to humic acid in the organic matter of the soil. Moreover, the results of the comparison of the average bands of Landsat 8 shows that bands 2, 3 and 4 are able to separate erosion and sedimentary surfaces at the 1% level, but thermal bands cannot be used to separate surfaces. Due to the difference in the color characteristics of erosional and sedimentary surfaces, as a result, it is possible to separate them based on reflectometric characteristics, and it is possible to separate eroded and sedimentary surfaces by using color indices.Conclusion: Due to the difference in the color characteristics of erosional and depositional surfaces, as a result, it is possible to separate them based on reflectometric characteristics, and it is possible to separate eroded and depositional surfaces by using color indices. The results showed that it was possible to model surface soil characteristics using quantified surface soil color data, and this hypothesis was confirmed by statistical investigations.

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