نشریه تحقیقات کاربردی خاک
سال دوازدهم شماره 1 (بهار 1403)

In this research, the effectiveness of five organic matter treatments were investigated to determine the amount of soil organic matter, rhizosphere fungal and bacterial population. Microbial population in rhizosphere and nutrients concentration in the aerial part of corn were carried out in the form of a randomized complete block design in three replications. Before planting maize, soil organic matter was measured before and after adding five organic matter treatments for one year. Then, maize was planted and harvested before it reached seed production, and the concentration of some nutrients in the aerial part of maize was determined. Also, the bacterial and fungal populations were determined in the rhizosphere and non-rhizosphere soils. The results showed that the largest population of rhizospheric bacteria in the treatments of Leonardite (231×104 cfu g-1 soil), fulvic acid (229×104 cfu g-1 soil) and calcium lignosulfonate (218×104 cfu g-1 soil) and the largest population of rhizospheric fungi in the treatment of calcium lignosulfonate (263×103 cfu g-1 soil) was observed to show a significant increase compared to the control treatment. The highest maize leaf nitrogen was observed in the treatment of fulvic acid (35.78 g kg-1) and calcium lignosulfonate (33.9 g kg-1), and the highest leaf phosphorus was observed in the treatment of fulvic acid (4.27 g kg-1) compared to the control treatment. In the treatments of fulvic acid, calcium lignosulfonate, and Leonardite, the highest amount of potassium was measured, and in the treatment of calcium lignosulfonate, the highest amount of calcium and magnesium was measured. Leaf sulfur was the highest in Leonardite treatment, but there was no significant difference with calcium lignosulfonate and fulvic acid treatments. The amounts of leaf micronutrients were the highest in the fulvic acid treatment, but iron and copper in the leaves were also the highest in the calcium lignosulfonate treatment.

Nowadays, the inoculation of cyanobacteria has been noticed as a new and environmentally friendly strategy in stabilizing erosion-prone beds. The current study was carried out with the aim of evaluating cyanobacteria inoculation in the biocrustation and stabilization of the dried-up beds of Lake Urmia in laboratory conditions. For this purpose, samples were prepared from the dried-up bed of Urmia Lake in Jabalkandi region of Urmia and were prepared after being transferred into erosion trays. The efficient cyanobacteria in soil stabilization were isolated and identified. Then, cyanobacteria were inoculated to the surface of the trays at four concentrations of 0, 1, 3, and 6 g m-2. After 120 days, the wind simulation was done at a speed of 72 km/h in six 5-minute intervals for 30 minutes on the trays. The results showed that the amount of soil loss in control treatments, 1, 3 and 6 g m-2 cyanobacteria inoculation was 12.35, 8.87, 4.11 and 0.73 kg m-2 min-1, respectively. Inoculation of cyanobacteria in treatments with concentrations of 1, 3 and 6 g m-2, respectively led to a declining of 28.15, 66.65, and 99.40 % of soil loss compared to the control treatment. The erodibility threshold of the control treatments and inoculation of 1 and 3 g m-2 of cyanobacteria biomass was at the beginning (minutes 0-5), minutes 10-15 and minutes 15-20, respectively. No noticeable erosion was observed in the inoculation of 6 g m-2 by the end of the experiment (minutes 30). The results showed that the inoculation of cyanobacteria with a biomass concentration of 6 g m-2 had the best performance in biocrustation and reducing soil loss.

Proper irrigation and optimal nutrition of plants have a significant effect on the yield and quality of the plant. To investigate the effect of irrigation period, sulfur and boron levels on turnip yield and quality, an experiment was conducted as the split split-plot (twice split plots) with randomized complete block design with three replications in the field. Irrigation as a main treatment in three levels (3, 5 and, 7 days), sulfur (0, 400, 800 and, 1200 kgha-1 from powdered sulfur source) and boron (0, 1.7, 3.4, and 5.1 kgha-1 from Boron acid source) were considered as a sub-treatments at four levels. The results showed that the highest and lowest dry weight of turnip tuber obtained from S800B3.4I3 and S0B0I7 treatments, respectively, had 82.3% differences. The highest and lowest concentrations of turnip tuber sulfur were obtained by 0.8% and 0.19% in S800B3.4I3 and S0B0I5 treatments, respectively. In this study, the synergistic effect between boron-potassium and the antagonistic effect was observed between sulfur-phosphorus and boron-nitrogen, sulfur, calcium, and magnesium. The highest boron concentration of turnip tuber was obtained 39.4 mgkg-1 in S0B3.4I3 treatment and the lowest boron concentration was 18.19 mgkg-1 in S1200B0I7 treatment. Overall, it can be stated that the highest turnip tuber yield and the best balance of macronutrients and boron were observed in S800B3.4I3 treatment.

Beneficial soil microorganisms protect the plant from stress by forming symbiotic relationships with the plant, and by converting and retaining elements in the soil, they feed the plant. This research was carried out in two parts: 1) isolation and purification of Fifty-five halophilic, alkaliphilic, and haloalkaliphilic isolates from different almond (Prunus amygdalus L.) rhizosphere soils in Khorasan Razavi province and investigation of some plant growth-enhancing properties in all isolates in the laboratory conditions to select superiors isolates; 2) test of the six best-selected isolates in the vicinity of the GN15 almond rootstocks to evaluate the effect of the isolates on the availability of phosphorus, potassium, iron, zinc, chlorine and sodium ions in four saline-sodic soils (2, 4, 8 and 16 dS m-1 salinity, and 9.69, 14.99, 14.21 and 19.72 SAR respectively). The results showed that the average production of plant growth-enhancing properties for alkaliphilic, haloalkaliphilic and halophilic isolates was for the production of indole-3-acetic acid (213.93, 77.13 and 15.98 mg L-1), the solubility of mineral phosphates (127.55, 73.99 and 40.19 mg L-1) and the production of exopolysaccharides (578.11, 284.54 and 35.90 mg L-1). The use of bacteria stabilized the pH in the range of 7 to 7.5 and significantly reduced soil electrical conductivity at high salinities (8 and 16 dS m-1) and increased exopolysaccharides. The highest concentration of phosphorus and chlorine anions in soil was observed in alkaliphilic bacteria treatment; the highest concentrations of soil potassium, iron, zinc, and sodium were affected by halophilic bacteria. The highest ratio of K/Na in soil was obtained in the treatment of halophilic (15.3), alkaliphilic (11.8), and haloalkaliphilic (9.4) bacteria, respectively. All kinds of indigenous bacteria of halo-alkaliphilic bacteria showed more efficiency in converting and maintaining nutrients in salinity more than 8 dS m-1 and SAR higher than 15.

In order to investigate the effect of different levels of biochar and biological fertilizer (Arbuscular mycorrhizal and Azospirillum lipoferum) on agricultural properties and quality of chamomile essential oil, a factorial experiment based on randomized complete block design with 12 treatments and three repetitions was conducted in Beiranshahr region of Khorramabad city in 2019-2020 cropping year. The factors included: application of biochar at three levels (0, 10 and 20 tons per hectare) and inoculation of biological fertilizers at four levels (without inoculation (control), inoculation with arbuscular mycorrhiza, inoculation with Azospirillum lipoferum and double inoculation of arbuscular mycorrhiza and Azospirillum lipoferum). The results showed that the interaction effect of biochar and biological fertilizers on the number of branches per plant, flower diameter, number of flowers per plant, biomass yield, economic yield (fresh flower), carotenoid content and essential oil yield at the probability level of one percent and on plant height and essential oil percent it was significant at the five percent probability level. Combined use of biochar and biofertilizers in the treatment of using 20 ton.ha-1 of biochar and double inoculation of mycorrhizae and Azospirillum lipoferum compared to other fertilizer treatments, has the highest values of biological yield (174.3 g plant-1), economic yield (3 56.5 g plant-1), essential oil percentage (0.440 %), and essential oil yield (24.6 g plant-1). Also, the use of 20 ton ha-1 of biochar showed more total flavonoids (0.43%), and carotenoids (1.56 mg/g) than other treatments. The highest percentage of camazolin (0.09%) was observed in the double inoculation treatment of mycorrhiza and Azospirillum lipoferum. The results showed that the use of biochar as an organic fertilizer of natural origin along with the inoculation of biological fertilizers increases the quality and quantity of chamomile medicinal plant products in the field and also maintains the balance of the environment.

Recently, using bio-amendments, especially biochar, has been considered to manage and improve water behavior in the soil of agricultural lands. However, the effect of biochar in a long-time period is one of the challenges. The aim of this research was to measure the physical and hydraulic components of the soil changes from the application of biochar in a short-time period at the laboratory conditions and on the small-scale trays filled by an agricultural disturbed soil. To this end, the bulk samples were taken from the research farm of Urmia University, and the samples poured into the small trays, they were treated by no biochar adding (control) and adding biochar (4.76% of soil weight). After 40 days, some physical and hydraulic components of the soil were measured. The results showed that the values of bulk specific gravity, porosity, weighted and geometric mean of diameter, fissures, transmission pores, storage pores and residual pores of soil as physical components of soil did not change significantly with the use of biochar (p>0.05). The effect of biochar on the components of the soil moisture curve (from suction 2 to 15000 cm), the important potential points of the soil moisture curve including the Field capacity, Permanent wilting point and Available water capacity, as well as the parameters of soil moisture curve of Van Genuchten model was not significant (p>0.05). However, the findings showed that the role of biochar in reducing saturated hydraulic conductivity measured by constant-head method (from 35.13±1.33 to 21.43±3.26 cm day-1; 39% reduction) was significant (p<0.05). Based on the findings of the present research, the application of biochar did not have a significant effect on the physical characteristics and hydraulic behavior of the soil in a short period of time.

Soil desalination in drained fields is very important because soil salinity harms on crop yield. Therefore, for the optimal management of water and soil, and the sustainability of agricultural lands, salinity monitoring in soil is essential. In this study, 44 soil samples from the depth of 0-30 and 30-60 cm were prepared from drained lands, during one cropping year. Then, soil salinity and acidity map was produced by GPI, LPL, IDW, Ok, RBF methods. Evaluation of salinity at 0-30 cm showed that stable kriging in the first and third months, exponential kriging in the second month, RBF inverse multi-quadrant model in the fourth and fifth months, were the best models. The results 30-60 cm showed that stable kriging in the first and third month, Gaussian kriging in the second month, Exponential kriging in the fourth month, and RBF inverse multi-quadrant model in the fifth month were selected as the best model. Also, evaluation of pH at the depth of 0-30 cm showed that Spherical kriging in the first month, GPI with the first power in the second and fifth months, IDW with the second power in the third month and Exponential kriging in the fourth month had the lowest RMSE. Evaluation of pH at 30- 60 cm showed that stable kriging method in the first, third, and fourth months and GPI with the first power in the second and fifth months had the lowest RMSE. The problem of salinity and alkalinity was observed in most of the surveyed region, and the level of salinity in the surface layer of the soil was higher than in the deep layer. The comparison of the salinity map in different months shows that the salinity has been decreasing during the 5 months of monitoring and the general trend of pH changes is similar to EC.

The present study was conducted to investigate the impact of organic (vermicompost and biochar) and chemical (gypsum and elemental sulfur) amendments and combination of vermicompost and chemical treatments on salinity, sodicity, and biological characteristics of a saline-sodic soil. This study was performed as factorial with two factors (with and without microbial inoculation) based on a completely randomized design with three replications in greenhouse conditions. After mixing with different treatments, soil samples were kept in the field capacity for 120 days, and wheat was cultured for 150 days following leaching soil samples. The most important chemical and biological properties of all soils were determined after harvesting the wheat plants. The results showed that the effect of each of the main factors of chemical and organic treatments including microbial inoculation and without microbial inoculation significantly (at the level of 5, and 1%, respectively) decreased the pH, EC, and ESP, the interactions of the factors did not have a significant impact on reducing them. For both factors, the role of combined treatments in improving the above indices was significantly greater than individual treatments. The main effect of experimental factors significantly affected (p <0.01) most biological indicators including basal respiration, substrate induced respiration, and soil microbial biomass carbon. However, the interactions of the factors significantly affected only microbial biomass carbon (p <0.05). Among all the treatments of both factors, the combined treatment of vermicompost and gypsum had the greatest effect on all three soil biological indices. This suggests that this treatment may have improved the soil ecosystem to increase and improve the activities of microorganisms by better improving soil chemical conditions than other treatments (such as reducing soil salinity and pH), and providing a substrate with more degradable carbon storage.