Soil, Water and Plant Relationships
Hossein Beyrami; Hossein Parvizi; Amir Parnian; Hadis Hatami
Abstract
ABSTRACTIntroductionSoil and water salinization is a worldwide problem, especially in irrigated areas, causing decrease in crop yield and the continuous loss of arable fields. Halophytes are the natural genetic source of salt tolerance traits and can be used for revegetation and remediation of salt-affected ...
Read More
ABSTRACTIntroductionSoil and water salinization is a worldwide problem, especially in irrigated areas, causing decrease in crop yield and the continuous loss of arable fields. Halophytes are the natural genetic source of salt tolerance traits and can be used for revegetation and remediation of salt-affected lands, and also as an alternative crop or biofuel. Due to the limited quality of water resources in the country and considering that the major regions of Iran's area are considered to be arid and semi-arid, it is important to cultivate plants with high tolerance to environmental stresses such as drought and salinity. The quinoa (Chenopodium quinoa Willd.) plant is important because of its ability to be cultivated in saline areas and irrigated with saline water. According to previous research, quinoa is an optional halophyte, and its irrigation is possible up to sea level salinity. Quinoa (Chenopodium quinoa Willd.) is one of the plants that has outstanding economic and agronomic advantages among the crops; it is particularly important in terms of forage production. There is no reliable and accurate information about the amount of water consumption by this plant in Iran. Considering the climatic characteristics and water shortages in the country, as well as the development plan for the cultivation of this plant due to its high nutritional value, attention to its water requirement becomes more important. For this reason, the importance of precise irrigation design and planning is needed in order to improve the performance of irrigation water usage in this region.Materials and MethodsThis research is conducted aim to determine the effects of different levels of moisture and salinity on the yield, some morphological traits, and some yield components of quinoa (Chenopodium quinoa Willd.) in field conditions during two growing seasons (2020-2022) in Yazd, Iran. The experiments were carried out in a factorial experiment in a randomized complete block design, which included two irrigation water salinity levels of 5 and 12 dS/m and four irrigation levels of 60, 80, 100, and 120% to provide the amount of allowable moisture depletion (MAD equal to 50%) in the root zone, in three replications. Experimental plots were designed with dimensions of 5×7 meters. Applying the amount of irrigation was done according to the determination of the field capacity levels and the permanent wilting point moisture measured (using a pressure plate device) before the start of the experiments. In this regard, according to this information, on the day of irrigation, the amount of soil moisture in each of the plots was measured at the root zone, and based on the treatments, the amount of water required was calculated, and irrigation was applied to the determined moisture level. Irrigation was carried out in the form of flooding, and the volume of irrigation water for each treatment was controlled by the volume contour and applied separately at each interval. At the end of the experiment, quinoa was harvested in a one-square-meter grid, and then plant height, panicle length and width, and stem diameter were measured. After the plant's drying, the weight of the seeds and the weight of the whole shoot were measured in different treatments.Results and DiscussionThe results showed that the different levels of salinity and soil moisture cause significant changes in biomass yield, seed yield, and harvest index. Also, the results indicated that changes in salinity levels and moisture levels caused significant differences in plant height, stem diameter and panicle length, panicle width, and 1000-seed weight (P<0.01), but their interaction was not significant. For two levels of salinity, the maximum biomass (9.28 tons/ha) was observed by supplying 100% of the depleted soil moisture based on MAD = 50%. According to the yield-water use function, the maximum seed yield for 5 and 12 dS/m irrigation water salinity was observed in treatments that supplied 115% and more than 120% of depleted soil moisture based on MAD = 50%, respectively. With the increase in salinity stress from 5 to 12 dS/m, biomass weight decreased by 23% and seed yield decreased by 17%. Based on the results, the average volume of applied water in fall cultivated quinoa under the 5 dS/m irrigation water salinity was 4900 m3/ha during the growth season (90 days).ConclusionIn the autumn planting of the Titicaca variety of quinoa, with a planting period of about 90 days in arid and semi-arid regions like Yazd, water consumption is about 450 to 550 mm. But in conditions of moisture deficiency, it is possible to grow this plant. Because it has a lower yield reduction slope than other plants under drought and salt stress conditions. Furthermore, the results indicated that the salinity of the soil profile increased in deficit irrigation conditions (60% and 80% of depleted soil moisture based on MAD = 50%) due to the lack of leaching requirements.
Soil, Water and Plant Relationships
hoda karimi; Shahriar Mahdavi; nasrin hasanzadeh; rouholah karimi
Abstract
Introduction Soil and water pollution, especially pollution by heavy metals such as cadmium,, has been noticed in many modern urban and industrial societies. If heavy metals accumulate in the soil, the capacity of the soil to keep the metals decreases, as a result, they enter the product and their bioavailability ...
Read More
Introduction Soil and water pollution, especially pollution by heavy metals such as cadmium,, has been noticed in many modern urban and industrial societies. If heavy metals accumulate in the soil, the capacity of the soil to keep the metals decreases, as a result, they enter the product and their bioavailability increases. Today, the use of biochar is suggested as a healthy method to control heavy metal pollution in the soil.In this research, in order to investigate the concentration of cadmium metals in soil and leaves in the exposure of cadmium stress and using biochar to investigate some physiological indicators of leaves and also to investigate the level of soil composition in 2 varieties of grapes in Malayer city, grape cuttings in plastic pots It was cultivated in the research greenhouse of Malayer University and Faculty of Agriculture.Materials and Methods In this experiment, the effect of biochar on two grape varieties (white Soltana and perlet) was investigated in the face of 100 mg/kg cadmium stress. After applying cadmium stress and using biochar (3% by weight) in the tested pots, The soils of the rhizosphere area were collected after 2 months of applying stress, and the cadmium concentration was done in the form of 5-stage classification in the research laboratory of Malayer University and finally analyzed by atomic absorption device. Leaf samples were also collected after about 2 months of applying stress and biochar, and physiological indicators such as ion leakage, chlorophyll, phosphorus and relative water content were measured.The data related to each treatment (three replications) were carefully recorded and analyzed using SPSS software. EXCEL software was used to draw graphs. Duncan's test was used at a significance level of 1%.Results and Discussion The results showed that cadmium stress decreased the amount of chlorophyll and the relative content of water and also increased the amount of ion leakage. It was also observed that the application of biochar in both grape varieties increased the relative content of water, chlorophyll and phosphorus and reduced the amount of ion leakage to some extent. In the chemical forms of the soil, the use of biochar caused the reduction of exchange and carbonate forms and the increase of organic, oxide and residual forms. Biochar changed the easily replaceable parts of cadmium to those that are less available. In the conditions of cadmium stress, the use of biochar in soil can play a very important role in plant indicators such as relative water content, ion leakage, chlorophyll and phosphorus.The application of biochar decreased the fraction of exchangeable and carbonated cadmium, while the forms bound to Fe-Mn oxide, organic form and residual fractions increased.It was observed that the availability of heavy metals in the soil was significantly reduced with the addition of biochar compared to the control. Biochar significantly reduced ion leakage in both grape cultivars compared to untreated soil. In the organic form, the white Soltana variety in the presence of biochar and stress of 100 mg/kg of cadmium in the soil (6.57) compared to the samples without the presence of biochar (3.39) had an increase of 48.40% in the average concentration of cadmium. In Perlet cultivar, the percentage of increase was 21.45%, all of which showed an increase in organic form in the presence of biochar.Cadmium in soil in exchangeable and carbonate forms decreased after biochar application.In the residual form, the White Soltana variety in the presence of biochar and stress of 100 mg/kg of cadmium in the soil (20.88) compared to samples without the presence of biochar (15.47) had an increase of 34.97% in the average concentration of cadmium. In Perlet cultivar, the percentage of increase was 30.34%, which all showed the increase of residual form in the presence of biochar. Our results showed that the application of biochar can reduce the availability and toxicity of cadmium. Conclusion According to the results of this research, the application of biochar in the soil can be considered as an efficient management solution to control cadmium in areas contaminated with this heavy metal and can cause positive changes in plant leaf indices.Changes in the concentration of cadmium in different soil forms of grape cultivars as a result of the use of grape trunk biochar show that the use of biochar is a good strategy to reduce the risks of transferring cadmium to humans and the environment in metal-contaminated soils.
Soil, Water and Plant Relationships
Javad Zamani; Mohammad Ali Hajabbasi
Abstract
Introduction Due to the difficulties in observing root growth in soil, our knowledge regarding soil-root system is limited. The roots are the hidden half of the plants but our knowledge of root’s growing is limited. Now, there are some methods and devices that have been used to analyze and monitoring ...
Read More
Introduction Due to the difficulties in observing root growth in soil, our knowledge regarding soil-root system is limited. The roots are the hidden half of the plants but our knowledge of root’s growing is limited. Now, there are some methods and devices that have been used to analyze and monitoring roots architecture and growth and their relation with soil. The assessment of the root growth of plants is possible with some photographic techniques such as neutron radiography and tomography, as well X-Ray imaging, but the use of these methods for root studies is very costly especially in Iran. The use of the rhizotron can also be one of the most practical and cost effective methods. The rhizotron is a box with a transparent side and uses to study the roots growing by photography or drawing roots on transparent acetate sheets. Here we aimed to introduce the rhizotron as a technique for studying plant roots, and conducted this study to investigate the effects of heterogeneous petroleum pollution in soil and endophytic fungus on growth and distribution of maize root. Materials and Methods In order to bring rhizotron forward as a method for in situ assessment of growth, establishment and distribution of plant roots a greenhouse experiment was performed. The effect of Piriformospora indica and soil petroleum polluted layers on the growth and distribution of maize (Zea mays L.) roots was studied. The rhizotrons had a wooden frame and back plate, and a removable front cover made of a 4 mm thick glass plate. The inner space was 30 cm high, 20.5 cm wide, and 1.5 cm thick (Figure 1a). The rhizotrons were placed on a rack with a 45˚ inclination to induce roots growing along the front glass to enable visual growth monitoring. The front glass plate was covered with an opaque black plastic to prevent light entering except for the times of observation. Two different patterns of soil-petroleum contamination layering were generated in the packings of the rhizotrons. 1) a shallow layer of 2.5 cm thick petroleum-contaminated soil, underlying of a 2.5 cm and above a 22.5 cm layer of uncontaminated soil (NSC), and 2) 27.5 cm of uncontaminated soil (‘control’). The packing procedure was layer by layer using uniform filling in all three cases. The contaminated soil layers were covered with a 2.5 cm layer of uncontaminated soil in order to facilitate plant establishment. The experiment with three replications was included as the packing methods each for growing maize plants inoculated with and without P. indica, and plant-free controls. The root development was recorded 12, 16, 22, 26, 33, and 45 days after transplanting by tracing all roots that were visible through the front glass on acetate transparencies, then were scanned at 300 dpi and analyzed for parameters such as root length, number of root tips and depth of rooting using the SmartRoot plugin of the software package ImageJ. After the last recording, the experiment was terminated. Roots and shoots were separated after harvesting, weighed and oven-dried. Rhizosphere soil samples were taken from the layer 2.5–5.0 cm below the soil surface for total petroleum hydrocarbons analysis. Results and Discussion The results well showed that root length, root depth and number of root tips could be monitored by this method. The presence of petroleum pollution in the soil significantly decreased the growth and distribution of roots but inoculated plants had more root length and root depth than uninoculated plants. The number of root tips which representing lateral distribution of roots had similar trend with root the length and they were significantly increased in the inoculated plants as compared with uninoculated ones. Results showed that inoculation of maize by P. indica increases root biomass more than the aboveground biomass. Conclusion Despite the limitation in the study of the effect of soil treatments on the growth and distribution of plant roots, the use of rhizotron could be a technique to solve this limitation. Our study proved that by using of rhizotron we can show the growth and 2-dimension distribution of plant roots, while the effects of treatment and root-soil interaction could also be assessing by this device.
Soil, Water and Plant Relationships
F Kamyab Talesh; B Mostafazadeh Fard; M Vazifedoust; M Navabian; Shayannejad M
