مجتبی یحیی آبادی

Nanotechnology involves nanomaterials that are less than 100 nm as an interdisciplinary and pioneering technology has solved many problems in the fields of agriculture. The use of iron nano-fertilizers in order to control the release of nutrients can achieve sustainable agriculture by reducing the consumption of chemical fertilizers. Nano CDs (carbon dots) are a new system or carbon material between molecule and condensed solid, which gathers the characteristics of nano effect, surface functional groups and carbon elements. Therefore, it shows three basic functions of optics, chemistry and biology, and has multiple functions and applications. In addition, the abundant hydrophilic functional groups on the surface of CDs, small size and other structural characteristics made it show great advantages in promoting crop growth and enhancing photosynthesis and stress resistance. The aim of this study was to investigate the effect of iron nano carbon dot fertilizer application on vegetative growth parameters of sorghum plant in a calcareous soil.

Iron nano carbon dots were synthesized with lemon juice (carbon source), ethylenediamine and iron sulfate (iron source) by hydrothermal method. Coating of nanoparticles with poly lactic acid was done by co-precipitation method. Characterization of iron nano carbon-dots to confirm the successful loading of iron on the surface of carbon dots and also successful coating was done by UV-VIS, EDAX, FTIR, TEM and SEM device analyses. Some chemical properties of nanocarbon dots such as pH, electrical conductivity and salinity index were measured. Sorghum cultivation was done in the greenhouse of Isfahan agricultural and natural resources research center with a factorial design in 3 replications. The first factor was foliar spraying in three levels (distilled water, iron sulfate and no coating iron carbon dot with a concentration of 3 per thousand) and the second factor was soil application of iron carbon dot (with and no coating) in 5 levels including iron carbon dot, no coating and coated each in two levels (5 and 10 mg Fe kg-1 soil). Foliar spraying of sorghum at the eight-leaf stage was carried out by iron carbon dot and iron sulfate with a concentration of 3 parts per thousand. After the plant growth period (4 months), growth parameters such as the number of leaves, stem height, stem diameter, and fresh and dry weight of stem and leaves were measured. Also, the concentration of iron in plants and soil was also measured.

No coating iron nano carbon dots had 4.98% total iron and polylactic acid coated carbon dots had 1% iron. According to the successful results on carbon dots, they were confirmed with UV-VIS and FTIR devices. Based on the results of leaf number (6/60), stem height (35.52cm), stem fresh weight (24.73 g plant-1), leaf fresh weight (24.39 g plant-1), leaf dry weight (5.37 g plant-1) and the dry weight of the stem (4.73 g plant-1) was related to the interaction effect of no coating iron carbon dot soil treatment with a level of mg Fe kg-1 soil 1 with carbon dot foliar spraying (concentration 3 per thousand). The highest amount of iron in the stem (211 mg kg-1) and leaf (186 mg kg-1) is related to the carbon dot iron soil treatment with a level of 10 mg Fe kg-1 soil and the highest amount in the soil (5.92 mg kg-1). It was related to the interaction effect of iron carbon dot soil treatment coated with polylactic acid polymer (level of 10 mg Fe kg-1 soil) with carbon dot foliar spraying (concentration 3 parts per thousand).

Among the foliar treatments with iron carbon dot and ferrous sulfate heptahydrate, the treatments that were in the group of foliar treatments with nano carbon dot iron had the most positive performance. The treatment of no coating iron carbon dot and then the treatment of iron carbon dot coated with polylactic acid, with level of 10 mg Fe kg-1 soil which simultaneously applied soil and foliar application with carbon dot with concentration 3 parts per thousand showed the best performance. Therefore, these two types of synthesized nano fertilizers are suitable for sorghum cultivation and can be used as a type of iron fertilizer for agricultural purposes.

The most obvious problem of calcareous soils is lack of plant available iron. Nano fertilizers are a suitable option to meet the needs of the plant with the high efficiency. The aim of this study was the green synthesis of nanocarbon dot iron fertilizers in two forms, uncoated and coated with polylactic acid polymer, and the incubation study of these fertilizers in a period of one month in a calcareous soil.

The green synthesis of iron nano carbon dot sample was done using lemon juice (as the carbon base of fertilizer) and Ferrous sulfate heptahydrate by hydrothermal method and the iron nano carbon dot sample was synthesized by polylactic acid polymer coating and test samples after synthesis to confirm the loading of iron on the carbon dot sample and also to confirm the successful coating of the synthesized iron nano carbon dot fertilizer by means of UV, XRD, Fluorescent Spectrophotometric, TEM, FESEM, EDAX, FTIR, DLS and Zeta Potential were characterized. In order to investigate the effect of synthesized iron nanocarbon dot on the availability of iron in a calcareous soil, an incubation experiment was conducted in a completely random design in 3 replications. The treatments include control (without nano carbon dot application), iron sulfate, sequestrin (commercial) and synthesized iron nano carbon dot loaded with iron (as two separate treatments without coating and coated with polylactic acid polymer) at levels 5, 10 and 20 mg Fe kg-1 soil (total of 9 treatments with 3 replications). At the end of the incubation period (720 hours), the extractable iron content of the soil was determined with DTPA. Also, in order to investigate the changes in the extractable iron of soil with DTPA with time, the amount of iron extracted in soil with DTPA in three times of 3, 360 and 720 hours in control treatments without fertilizer, treatment of 5 mg kg-1 soil iron soil from different sources of iron were compared with each other.

The successful loading of iron on the surface of nano-carbon iron dots without coating and coated with polylactic acid polymer was confirmed by XRD, UV-VIS, FTIR and scanning and transmission electron microscopes. The amount of total iron in the uncoated sample was equal to 4.98% and in the sample coated with polylactic acid it was equal to 1%. The results of the incubation showed that extractable iron in the soil with DTPA increased significantly.The highest concentration of iron in the soil at the end of 720 hours is related to the sample coated with iron nano carbon dot with polylactic acid polymer with an iron concentration of 20 mg kg-1 equal to 9.58 mg kg-1. Also, by examining the changes in iron release in treatments with a concentration of 5 mg kg-1 in three time periods of 3, 360 and 720 hours, it was observed that the coated treatment caused a significant increase in iron compared to the iron sequestrin treatment. Iron sequestrin treatment after 720 hours compared to the first 3 hours increased by about 60% (from 5.19 to 8.28 mg kg-1), while the amount of iron extracted with DTPA in the nano carbon dot iron coated treatment In this period of time, it increased by about 400% (from 1.36 to 6.63 mg kg-1).

According to the results of the research, it can be said that among the experimental treatments regarding the slow release of iron, the sample coated with natural and biodegradable polylactic polymer with an iron concentration of 20 mg kg-1has the highest iron release compared to had other treatments,

The large area of saline soils in Iran and decreasing in quality of these soils require that the effectiveness of conservation tillage systems in such lands be investigated. This project aims to determine changes in soil physical properties in three different types of tillage system and plant residue management, including: 1) conventional tillage system and removal of crop residues from soil surface, 2) reduced tillage system and preservation of crop residues, and 3) no tillage system and preservation of crop residues in rotation of barley and safflower in a saline soil with irrigation water salinity of 5.35 dS/m for four years. Some soil physical properties such as bulk density and porosity, and aggregate stability indices of mean weight diameter (MWD) and geometric mean diameter (GMD) were measured in soil samples prepared from the layers of 0-10, 10-20 and 20-30 cm. After each crop rotation period, water infiltration into the soil was measured and the modified Kostiakov model was fitted to obtain the optimized parameters. The results of variance analysis of the data in the four years of the experiment showed that the difference in most of the soil properties at the end of the experiment was significant due to the tillage treatments compared to the control. The highest MWD and GMD (2.53 and 1.90 mm, respectively), porosity (51.2%) and final infiltration rate (31 cm/h) were observed in the no-tillage system. while the lowest MWD and GMD (2.02 and 1.29 mm, respectively), porosity (47.8%) and final infiltration rate (3.5 cm/h) were recorded in the conventional tillage system. Overall, our findings showed that the increment in the soil organic matter due to the implementation of conservational tillage treatments improved the stability of soil aggregates and increased soil porosity and water infiltration into the soil.

In order to investigate the response of safflower cultivars to different levels of soil P for its optimum use, this study was carried out in Darab, Isfahan, Dezful, and Kerman regions as a factorial experiment with a randomized complete block design in three replications in two cropping seasons (2015-2016). The first factor was cultivar (Padideh and Goldasht cultivars for Isfahan and Darab and Goldasht and Soffe for Kerman and Dezful) and the second factor was different rates of triple super phosphate (TSP) including zero, 50, 100, 150, and 200 kg.ha-1. The soil available phosphorus in Isfahan was 10.2, Darab 11, Kerman 7 and Dezful 7.18 mg kg-1. Based on the results, the effect of cultivar on safflower seed yield in Isfahan and Dezful was significant (p<0.01) and (p<0.05), respectively, but in Darab and Kerman, the difference between the two cultivars was not significant. The effect of TSP rate on grain yield in all four regions was significant (p<0.01).  The interaction effect effects of cultivar-phosphorus on the grain yield was significant only in Isfahan region (p<0.05). In Isfahan and Dezful, the highest yield was obtained from the Goldasht at the rate of 50 kg.ha-1, significantly different than the control. In Kerman, the highest seed yield was obtained from Goldasht and at 150 kg ha-1 TSP, significantly different than other treatments. With the application of TSP in Darab, Dezful and Isfahan, 20%, 78%, and 28%, increase in grain yield was observed compared to the control, respectively. The best benefit-to-cost ratio in Darab and Kerman regions was obtained from Goldasht for 100 and 150 kg.ha-1 TSP, respectively, while in Dezful and Isfahan it was obtained for 150 kg ha-1 TSP in Soffeh and Padideh, respectively. In general, for safflower in warm regions with soil available P of 10 mg kg-1, 50 kg.ha-1 TSP and for areas with soil available P of 7 mg.kg-1, 150 kg ha-1 TSP can be recommended.

In order to investigate the effect of different organic fertilizers on yield and some physiological characteristics of potato under drought stress conditions, an experiment was conducted in the form of split plots, based on randomized complete block design with three replications in 2018 at Baraan region in Isfahan. The applied treatments include drought stress based on the fraction of Allowable Water (AW) or Management allowed Deplition (MAD= 45% as a control, 55%, 65% and 75% in main plots) and organic fertilizers including vermicompost (7 ton ha-1), municipal waste compost (15 ton ha-1), cow manure (50 ton ha-1) and control (without fertilizer application) were in the sub-plots. Results showed that the drought stress reduced yield and its components and reduced leaf chlorophyll content (p≤0.01). Comparison of means showed that potato yield in vermicompost treatment without drought stress reached 33 tons per hectare. Intraction of vermicompost and irrigation after 65% depletion of AW (reduction of 20% in water consumption), led to the production of 23 tons per hectar potato. Under these stress conditions, compost treatment also resulted in potato production of 21 tons per hectar. The interaction of vermicompost and irrigation after 75% depletion of AW (30% reduction of water consumption), Leaf chlorophyll reached 12 mg/g, the same as situation at no application of vermicompost and drought stress. Also, the highest amount of proline was measured in the interaction of MAD=65% and compost and vermicompost treatments with 21.2 and 24 mg/g, respectively. In general, the application of organic fertilizers could help to reduce the negative effects of drought stress.

Earthworms have been used as adsorption markers to prove the biological availability of chemical fertilizers in soil. This study aimed to determine the amount of nutrient uptake in some earthworm species in an orchard soil. In this study, the uptake of nitrogen, phosphorus, potassium, zinc and iron by the application of different chemical fertilizers urea, ammonium sulfate, diammonium phosphate, solupotas, NPK compound fertilizer, NPK fertilizer with cow manure, zinc chelate and iron chelate in five Earthworm species were studied. Treatments were applied in three replications in a randomized complete block design and data were analyzed by ANOVA. Results showed that epigeic species were more active in the uptake of elements such as nitrogen and phosphorus. Meanwhile, E. fetida was more active in nitrogen uptake of urea (72%) and ammonium sulfate but was not active in uptake of phosphorus from diammonium phosphate fertilizer. On the other hand, the presence of organic matter in the fertilizer treatments caused less nitrogen and phosphorus uptake by the worms and under these conditions, the anecic species have performed poorly in the adsorption process. Chelating of nitrogen and phosphorus in organic compound molecules has reduced their adsorption power. In addition, E. fetida showed a higher tendency to adsorb iron (52%) and zinc (50%) in treated soil than control soil. In order to reduce the negative effects of chemical fertilizers on soil organisms, it is recommended to reduce their consumption in shallow soils.

Earthworms have been used for many toxicity assay and environmental assessments because of the remarkable role they play in the biological, chemical and physical processes of the soil. The purpose of this study was to investigate the impact of chemical fertilizers on the density of earthworms in the soil of an orchard. One square meter area was considered as experimental plot. Seven different types of fertilizers including Urea, Ammonium sulfate (AS), Diammonium phosphate (DAP), Solupotas, NPK (15-5-25), (NPK+OM) and organic manure (OM) as experimental treatments were studied, based on the soil test. Abundance of worms were evaluated in two stages of time and in 2 depths of 0-20 and 20-40 cm of soil. In the first stage, 20 days after the addition of fertilizers, and in the second stage, 60 days after fertilization, earthworms were sampled and their number changes were measured. Treatments were applied in three replications and the data were analyzed using one-way ANOVA (using the GLM process) by SPSS software. The results of the means comparison showed that on the 20th day, at 0-20 cm soil depth, E. fetida species abundance was decreased significantly in AS and Urea treatments compared to the control plot (p˂0.05). From epigeic group, D. hortensis species showed more compatibility and its population in AS treatment was more than that of Urea treatment. Results also showed that the anecic L. terrestris, had a greater tolerance to chemical fertilizers compared to the A. Longa species.

Earthworms, due to their beneficial role in agroecosystems, are used as indicator species for monitoring the impact of pollutants, changes in soil structure and agricultural practices. The purpose of this study was to investigate the impact of chemical fertilizers management on the density and live weight of earthworms in the soil of an orchard.
Research was carried out in an orchard in Isfahan province. One square meter area was considered as experimental plot. After plowing and grooving at a depth of 5 centimeters per plot, common fertilizers were applied, based on the soil test. Chemical fertilizers such as urea, ammonium sulfate, diammonium phosphate, solupotas, NPK (15, 5, 25), zinc chelate, iron chelate and cow manure were used as experimental treatments with control (no fertilizer). Abundance and live weight of worms were evaluated in two stages of time and in 2 depths of 0-20 and 20-40 cm of soil. In the first stage, 20 days after the addition of fertilizers, and in the second stage, 60 days after fertilization, earthworms were sampled and their number and biomass changes were measured. Treatments were applied in three replications and the data were analyzed using two-way ANOVA (using the GLM process) by SPSS software. In addition, the means were tested with the least significant difference (LSD) at the probability level of 5%.
The assessment of the worms was accomplished at two different depths and at two different times. Sampling in 20th day of experiment showed that at soil depths of 0-20 cm, urea, ammonium sulfate, diammonium phosphate, macro fertilizer NPK and iron chelate had significant negative effect on the abundance and weight of earthworms (p≤0.05). Meanwhile, cow manure (OM) and NPK treatments increased the population and biomass of earthworms. In the depth of 20 to 40 cm, the negative role of urea, ammonium sulfate, diammonium phosphate, NPK fertilizer and iron chelate was decreased, and the NPK maintained its positive role. On the 60th day of sampling, at 0-20 cm depth, urea, ammonium sulfate, diammonium phosphate and iron fertilizer reduced the population and biomass of worms in the soil. However, NPK, OM and zinc chelate (Zn) treatments increased the number of earthworms. At a lower depth (20-40 cm) on the 60th day, the earthworm population was not affected by any of the inorganic fertilizers and nitrogen and phosphate fertilizers not only had no negative effect on the activity of earthworms but also significantly increased their biomass (p≤0.05).
The results showed that chemical fertilizers could have a significant effect on soil organisms, including earthworms. These effects could vary according to the nature and extent of fertilization, as well as the depth of fertilizer usage. Accordingly, in order to reduce the negative effects of chemical fertilizers on soil organisms, it is advisable to reduce their application in shallow soils and when applying, organic fertilizers should be used along with chemical fertilizers.

Comparison of two species of earthworms involved in production of vermicompost from organic matter in municipal solid waste compost and cow dung were investigated. The T test results indicated that differences in nitrogen increases in both beddings by two species of earthworms were not significant. Total phosphorus in the final product of both bedding vermicompost was increased (p˂0.05). Meanwhile the difference between the two species of earthworm activity on phosphorus in manure vermicompost was not statistically significant but in urban waste vermicompost was significant (p˂0.05). Hence, Eisenia fetida has shown a better performance. There was no significant difference in the most number of the two species in cow dung bed statistically. The difference between the two species of earthworms in terms of the average number of cocoon is significant per day for each worm. Comparing reproduction parameters of two species of earthworms in compost bed show that although the differences between the two species in terms of the total number of cocoon, the average number of cocoon for each worm and the average number of cocoon for each worm per day are significant (p˂0.05) and Eisenia fetida exhibited better reproduction performance. Nevertheless, both species had no significant differences in mean of maximum number of studied species (p˂0.05). Comparatively results indicated that E. fetida has more growth rates and its replication cycle is shorter than that of D. veneta. In conclusion, species D. veneta have large biological similarities with species E. fetida. This convenient feature makes it possible to use this earthworm species in vermicomposting process.

Epigeic species of earthworms have high rates of consumption and digestion of organic matter. Short life cycles and high-reproductive rates, show high potential of them for vermicomposting process. In this study, Epigeic species earthworms of Isfahan Province were investigated. Species were collected from 10 locations and 20 habitats. During the study, four epigeic earthworm species based on morphological markers including earthworm length and diameter, number of segments, number of setae in each segment, color and location of clitellum and tubercles were identified, including: Dendrobaena veneta (Rosa, 1886), Eisenia fetida (Savigny, 1826), Dendrodrilus rubidus (Savigny, 1826) and Dendrobaena hortensis (Michaelsen, 1890). Dendrobaena veneta had the highest abundance and Dendrobaena hortensis had the lowest. Greatest number of Margalef richness index (0.910) was measured in Chadegan due to optimum conditions for ecological habitats and the lowest was recorded at a rate of zero in the region of Anarak.

Many of scientists, managers, and the public are interested in assessing the health of communities and ecosystems. This has resulted in increased studies of the usefulness of different indicators as a measure of stressors and contaminants. Monitoring ecosystem health requires the use of a suite of bioindicators that are biologically, methodologically, and societal, and can be used effectively over time to assess trends and provide early warning. In a successful and continuous management of lands, Bioindicators can be considered as constructive elements in assessment of soil quality. Earthworms are often referred to as bioindicators of soil quality, because they are an important part of soil ecosystem and are always present in the soils. Because of extraordinary role that earthworms have in physical, chemical and biological process in soils, and also because of the wide distribution of earthworms in soils, these creatures have been used for a lot of toxicity tests and environmental evaluations. Bioaccumulation of metals by earthworms can be used as an environmental indicator for availability of metals. In this article, the above topics including a variety of indicators and their application in land management and environmental assessments, and especially the use of earthworms as a bioindicator of soil quality in efficient monitoring will be discussed in details.

Most inoculation studies have focused on free-living diazotrophs, although a few reports indicate rhizobia can act as PGPR. In order to evaluate nitrogen fixation ability of different strain of Rhizobium legominosarum biovar phaseoli in common bean, a randomized complete block design including 6 rhizobial isolates(L-100, L 41, L-75, L-216, L-54 and L-139 selected from different provinces by soil & water research institute), one nitrogen fertilizer (400 kg Urea per ha) and one control plot (without seeds inoculated and fertilizer) in four replication was carried out in two field (Dehaghan & Esfarjan) at Isfahan province in 2003. Results showed that significant differences were observed in seed and dry matter yield, total nitrogen absorption, number and weight of nodules and seed yield among seed inoculated with different strains and non-inoculated controls. In Dehaghan field, seed inoculation with L-75 strain and in Esfarjan field, seed inoculation with L-54 and L-139 strains increased dry matter yield, total nitrogen absorption, number and weight of nodules and seed yield. Results also showed that seed inoculation with some rhisobia isolates increased micronutrients absorption. In Dehaghan field, inoculation of L-216 and L-75 strains led to higher absorption of Cu and Zn. Some isolates could not promote nitrogen absorbtion.

High intensity evaporation from the soil surface due to low air humidity and poor soilstructure and organic matter are constraints of agriculture in arid and semi-arid regions ofIran. Regionally, maintaining plant residue with tillage management is one method to improve these conditions. In this study, for a barley-corn rotation, four barley residue management methods for standing stubble (burning, burying, incorporating and leaving on the surface)were compared over four years at Isfahan Kabootar Abad Agricultural Research Station. The experiment was conducted using a randomized complete block design with six treatments and three replications. The tillage treatments for corn (second crop) were applied to the same plot every year and the plots were conventionally plowed every year for the first crop (barley).The first year results showed that no-tillage treatments reduced the yield due to insufficient contact of seed and soil which caused an inadequate number of seedlings per square meter.However, providing better seed-soil contact in subsequent years resulted in no significantdifference in the yield of the no-tillage treatment with other treatments. There was also no significant difference in yield and other crop establishment parameters between the othe treatments during the four years of the study. Incorporation, leaving the residue on the surface and burying to a depth of 25 cm resulted in 20%, 18%, 13% increases, respectively, in the average organic matter compared with burning after four years of testing. Results also showed that the earthworm population under the conventional method was significantly lower than for the no-till and reduced-till treatments. No significant difference in root dry weight to a depth of 60 cm was observed between treatments. After four years, the results of the study indicated that the forage corn production under no-tillage and reduced tillage had no adverse effect on biomass yield and can be an alternative method to the current tillage method. Therefore, anannual compilation system that combines conventional tillage for barley and reduced tillagefor corn production (after barley) is an alternative to reduce soil moisture evaporation insummer, increase soil organic matter and improve soil structure (increase population ofearthworms) instead of conventional tillage operations.

To study the relative toloranc of quince (Cydonia oblonga Mill.) rootstocks to Fe chlorosis induced by different bicarbonate concentrations of irrigation water, this study was conducted using four quince rootstocks (Q.A, Q.B, Q.C and PQBA29) in a factorial arrangement with five replications. All of rootstocks were irrigated with water containing different bicarbonate concentrations (0.0, 5.0, 10.0 and 15.0 mmol per liter). During growing season, some important traits such as general characteristics, trunk diameter, plant height, chlorophyll content as well as annual shoot growth of trees were measured and recorded. Result showed that bicarbonate in irrigation water had a significant effect on all measured plant traits in all quince rootstocks. Nevertheless, among four quince rootstocks, Q.A and PQBA29 had the highest tolerance to ammonia bicarbonate in irrigation water. Results implied that these rootstocks may tolerate higher bicarbonate concentrations as well as produce reasonable yield in such conditions. It is concluded that these two quince rootstocks can be introduced as suitable rootstocks under these conditions as well as to be used in breeding programs.