نشریه تحقیقات کاربردی خاک
سال یازدهم شماره 3 (پاییز 1402)

In recent years, carbon-based nanomaterials have been widely applied in agriculture due to their higher biocompatibility, cheapness, and important effects on the growth and production of plants. In this research work, a new fertilizer based on carbon nanomaterials (Zn-NCDs) was synthesized using citric acid, urea, and zinc chloride as the precursors via a one-pot simple hydrothermal method and characterized by FT-IR, CHN, EDS, DLS, PL, UV-Vis, FESEM, TEM, ICP-OES, and zeta potential. Then, the effects of the Zn-NCDs as a zinc source were evaluated on the growth and the improvement of zinc uptake in the shoot of wheat (Triticum aestivum, Sirvan) under a hydroponic condition using a completely randomized design, with three replications and three concentrations of 2, 4, and 8 mg L-1 compared to ZnSO4, and Zn-EDTA (with a concentration of 2 mg L-1). Instrumental analysis showed that Zn-NCDs nanocarriers have uniform dispersion, no apparent aggregation, and an average particle size of less than 5 nm. Also, the presence of carbon, nitrogen, oxygen, and zinc in the structure of Zn-NCDs was confirmed. The hydroponic culture revealed that Zn-NCDs was as effective as two commercial fertilizers, ZnSO4 and Zn-EDTA, in providing zinc in the shoot of wheat plants. Also, Zn-NCDs significantly increased the percentage of nitrogen and protein in shoot compared to ZnSO4. The results of the soil incubation demonstrated that the zinc release from NCDs nanocarrier continued for 30 days.

The drought crisis of Urmia Lake has led to the emergence of dried-up and wind-erosion-prone beds. Therefore, it is necessary to create and accelerate the natural and artificial revitalization of vegetation to stabilize the dried-up beds of Urmia Lake. Hence, this study was planned to measure and prepare the spatial distribution map of the organic nitrogen content of the dried-up beds of Urmia Lake based on field sampling as one of the essential nutrients for the revitalization of vegetation. To this end, 192 soil samples were taken from all dried-up beds of Urmia Lake during the Summer of 2020. We then measured the organic nitrogen content of the soil samples. Then, using the ordinary Kriging method, the content of nitrogen in non-sampled beds was estimated through the values of sampled points, and its spatial variability map was prepared. The minimum, maximum, and average nitrogen content in the dried-up beds of Urmia Lake was 0.010, 0.297, and 0.143%, respectively. The nitrogen content was low (0.117 to 0.153%), and very insignificant in most of the dried-up beds and margins of Lake Urmia, which was observed in the north, northwest, west, east and especially southeast parts of the lake. Whereas, the highest nitrogen percentage was in limited parts from the south to the southwest of Lake Urmia and was 0.189 to 0.297. Based on the findings, the implementation of managerial and technical measures in order to improve the nitrogen content of a large part of the dried beds and barren lands around Lake Urmia is necessary to achieve a successful revitalization of vegetation. However, measuring and preparing the spatial distribution map of other soil components is also suggested for future research.

Nitrogen addition, particle size, and microbial treatment are important factors in mature compost production. Therefore, this study aimed to investigate some physical and chemical parameters and nutrient content in wheat straw compost enriched with urea and Streptomyces. The incubation experiment was performed in a time-based, completely randomized design. To evaluate the effect of compost enrichment with Streptomyces and urea on available micronutrient elements, humification index of compost (E4/E6 ratio), pH, EC, C/N, temperature, Changes in moisture, and ash weight the following treatments (1) wheat residue size at three levels (R0 (<1), R1 (1-2) and R2 (2-4 cm)), (2) three levels of Streptomyces inoculation (S0 (0), S1 (0.5) and S2 (5%)), and (3) three levels of urea (U0 (0), U1 (8.05) and U2 (16.1 g kg-1)) with three replications were applied. The parameters were measured at different times during 90 days of incubation. A rapid increase in temperature in enriched compost with urea and Streptomyces treatment occurred in a shorter time than the control treatment. The pH value in all treatments decreased during the first 20 days of incubation and then increased. The C: N ratio significantly decreased due to the composting process. The humification index also reduced in the treated and control composts after 90 days of incubation. In general, the enrichment of compost with urea or Streptomyces showed increased nutrient values. However, the compost treated with Streptomyces and urea exhibited the highest values of nutrients compared to others. Our results showed that co-application of our isolate and urea can be used in composting process and improve soil properties better than non-treated compost. However, large-scale composting to prove the potentiality of the treatment in enhancement of compost quality is necessary.

Drylands have always been an important source of soil loss and sediment yield, so that suitable conditioner application can reduce soil erosion. This study conducted to determine the suitable rate of vinasse treatment in reducing runoff and soil loss on the loess soil of drylands in Kalaleh city, east of Golestan Province and in plots with 10 x 30 x 30 cm dimensions were done. This experiment had four treatments of vinas (0, 50, 100, and 150 ml) once at an average intensity of 70 mm per hour on three different slopes (20, 12, and 8 %) and once at three rainfall intensities (50, 70, and 90 mm/h) on a medium slope (12%) each with three repetitions for 30 minutes. Vinasse treatments were also sprayed evenly on the soil surface and given about 24 hours to balance with soil particles. Runoff was collected and volumetric measurement was done after precipitation. The remaining samples were dried. The soil losses was determined. The ANOVA results showed that differences between slope, rainfall and vinasse treatments and their effect were significant. However the treatments containing 50, and 150 ml vinasse had higher performance than the control in the component of runoff volume and soil loss. Of course, 100 ml vinasse treatment caused to reduce runoff volume and soil losses components. The effect of slope, unlike the intensity of precipitation, does not follow a specific trend, but the intensity of precipitation has a direct effect on the component of runoff volume and soil losses. In this experiment condition, the application of 100 ml vinasse could be effective in runoff volume and soil loss reduction.

Drying a large area of ​​Lake Urmia is considered a serious environmental challenge for the region and the country. Therefore, the knowledge of the physical and mechanical characteristics of Lake Urmia bed material is necessary to do engineering activities to regenerate it. One of the major problems related to lake bed sediments is the effect of the high percentage of organic matter with low shear strength, high salt concentration, and solubility of some matters on soil behavior. In this article, after performing different field and laboratory tests to determine soil properties, the Guelph penetrometer (2800KI) was tested up to a distance of 1 km from the width of the lake and in different areas of the lake (Hyderabad in Naghadeh, Chichest in ​​Urmia and the ​​Urmia-Tabriz causeway). In these three areas of the lake, by digging 20 wells with a radius of 4 cm and a depth of 25-30 cm at different intervals in a zigzag pattern up to a length of 1 km towards the inside of the lake, hydraulic conductivity was measured using a Guelph permeameter in two hydraulic heads of 5 and 10 cm for each borehole with two replications. The study results showed that the hydraulic conductivity for the two areas of Hyderabad and Chichest of Urmia, on average, for loamy soils, mainly near the shore of the lake, was estimated to be 0.175 cm/h; 5.34 cm/h for layered sand and 1.89 cm/h for the ​​area around Urmia-Tabriz causeway.

The values of rangeland vary, and there are significant temporal and spatial changes. Since rangeland are constantly changing, they play a crucial role in the economy and in the protecting the land and water. So it is crucial to grasp them and manage them properly. The middle "Kashkan" watershed in the "Lorestan" province was chosen in order to assess the capability of multi-spectral pictures from Sentinel 2 and Spot 5 satellites in creating rangeland density maps. Using ground control points and the region's digital height model, the photos were geometrically adjusted with an accuracy of less than 0.21 pixels. On the primary multispectral image of each satellite as well as the integrated image of Spot 5 and the rangeland density map, supervised classification utilizing the parallelepiped, minimum distance, maximum likelihood, and neural network classification techniques was carried out. Three density classes—5–25, 25–50, and 50% and above—were prepared for it. 117 ground control points were located on the topographic map of the area in question in order to measure the classification's accuracy. The global positioning system (GPS) was then used to pinpoint the locations of the points in the study area, and the ground reality map of the region was created using the determined coordinates. The Spot 5 image with PCA-3-1 band composition and a neural network classification algorithm, which had an overall accuracy of 70.53% and a Kappa coefficient of 0.65 compared to the Sentinel 2 image with PCA-8-2 band composition and a neural network classification algorithm, which had an overall accuracy of 65.72 and a Kappa coefficient of 0.08, produced better results, according to a study that examined the accuracy of classified images. This study showed that Spot 5 satellite photos outperform Sentinel 2 satellite images when creating rangeland coverage maps with three different densities. It is possible to use satellite images with spatial and spectral resolution suitable for creating a map of rangeland density and regulating and trying to prevent the destruction of rangeland in the west of the country over a certain period of time because the distances for aerial photography of rangeland areas in Iran are great.

To find the best treatment of cow manure mixing using the best tillage methods and improving sugarbeet yield and soil bulk density and chemical properties, a randomized complete block design the form of a strip plot was replicated three times. Three rates of manure (0, 20, and 40 t/ha) and five tillage methods were used. The analysis of two years of combined data showed that cyclotiller with the mean of 61093 kg/ha and sweep had the highest yield and effect on soil bulk density. Soil chemical properties like soil organic carbon, soil phosphorus, and soil potassium were also measured for data analysis. The results of two-years analyses of data also showed that the cow manure treatments caused more yield of sugarbeet and improved soil physical properties like reducing soil bulk density and soil compaction. Also, using secondary soil tillage machines of cyclotiller and sweep can improve the mixing of manure with soil and soil physical properties and yield of sugarbeet and sugar percentage. In other words, using a cyclotiller and sweep raised the yield and sugar percentage of sugarbeet and reduced soil compaction.

Cement factories are one of the most polluting industries in the world. In this regard, the purpose of this study is to investigate the contamination of heavy metals lead, nickel, cadmium, iron, manganese, zinc and copper in the soils around Darab Cement Factory. 30 soil samples were taken from a depth of 0-30 cm from the soil around the Cement Factory. Heavy metal concentrations were measured by atomic adsorption spectrometry. The results showed that the mean values of cadmium, nickel, copper, lead, zinc, iron and manganese in the soils of the region were 1.73, 35.52, 13.71, 27.98, 26.97, 1039.27, and 590.71 mg kg-1 respectively. The average cadmium in the soils of the region (1.71 mg kg-1) is higher than the maximum standard of cadmium in the soils of the world. The average concentrations of metals in the study area are Fe> Mn> Ni> Pb> Zn> Cu> Cd, respectively. The results showed that the mean concentrations of lead, nickel, zinc, copper and cadmium were significantly different from the maximum allowable amount in the soil and was less than that (P <0.01). The results of the risk index showed that 100% of the samples have a low risk index. The study area has a moderate degree of pollution in terms of manganese, cadmium, nickel and lead metals. The pollution load index for all stations is less than 1, indicating the pollution load index in the area close to the normal and non-polluted concentration. In general, although the concentration of heavy metals in the soils of the study area is not in a critical state of pollution, but planning to control the release of heavy metals and other pollutants should be considered.

Increased wind erosion and dust are the country's environmental issues, particularly in the border provinces. Every year, wind erosion and dust have several negative implications in the social, economic, cultural, and health. Dealing with these phenomena necessitates both short- and long-term planning. These phenomena can be controlled in a variety of ways. In this study, the performance of two biological (Microbial Induced Calcium Carbonate Precipitation) and chemical (polyvinyl acetate application) approaches was studied. Sampling was taken from one of the dust sources’ areas in Ilam province (0-30 cm depth). In this study, polymer polyvinyl acetate with five levels of zero (C0), 1 (C1), 1.5 (C2), 2 (C3), and 2.5 (C4), as chemical mulch and Bacillus sphaericus with three factors of bacterial strain (presence or absence of bacteria), nutrient content (with two levels of 0, 0.5 M) and volume of solution (123, 264 and 369 ml) as a factorial experiment in the form of the Completely Randomized Design with three repetitions have been used. The trays were placed in ambient conditions, and wind tunnel, penetration resistance, and aggregate stability tests were performed on all samples after 28 days. A double bacterial spray with 0.5 M of nutrients and a solution volume of 269 ml (BS2 C1 WC2) was shown the most efficient treatment for soil stabilization using the MICP approach. The best treatment for surface stabilization utilizing the chemical method was observed at 2.5 percent (C4). A comparison of these two methods showed that the rate of increase in penetration force, aggregate stability, and decrease in soil loss in the chemical method was higher than in the biological method. In a nutshell, the MICP approach is advised to manage dust storms in Ilam province.

Soil compaction is one of the effective factors in reducing soil physical quality, which due to tillage operations can affect the relationship between water, soil and crop yield. The aim of this study was to investigate the effect of some tillage treatments on the compaction behavior of a silty clay loam soil. Core sampling was carried out during three years of tillage after barley harvest. The experiments were conducted as a randomized complete block design with three treatments i.e. conventional tillage, reduced tillage and no-tillage in 6 replications. Soil compaction characteristics including pre-compression stress, compression index and swelling index were determined based on confined compression test )CCT) at 100 hPa matric suction. The results showed that the tillage treatment had a significant effect on pre- compression stress, bulk density and soil moisture at the confidence level of% 5. The lowest amount of pre-compression stress with a value of 19.95kPa is related to conventional tillage treatments and the highest value with a value of 31.62 kPa is related to non-tillage treatment. The compression index was showed the highest value in conventional tillage compared to other treatments. The results of cyclic loading-unloading at a constant stress level (i.e. 50% of pre-compression stress) showed that the studied soil was less sensitive to repeated loading for no-tillage than reduced and conventional tillage treatments which can be attributed to weaker structure for the later. As the conclusion, the no-tillage treatment can be described as a treatment being less susceptible to compaction. However, consecutive implementation of this tillage treatment might require subsoiling operations every few years to disturbed the deep subsoil hard pans.