ali khanmirzaei

The main objective of this study was to develop machine learning models for predicting soil organic carbon (SOC) content in agricultural soils enriched with calcium-rich materials in the central region of Iran. Soil samples were collected from 336 points in agricultural lands with two land uses, namely cropland and orchard, from Alborz Province. The soil organic carbon was measured using the Walkley-Black oxidation method. Remote sensing data, obtained from various sources such as Landsat 8 imagery and MODIS sensor, were utilized for soil organic carbon analysis. Three machine learning models, including Artificial Neural Networks (ANN), Support Vector Regression (SVR), and Gene Expression Programming (GEP), were employed in this study to estimate the soil organic carbon content. The results of this research demonstrated positive outcomes, indicating that the simultaneous use of Landsat 8 imagery and MODIS sensor data through the SVR model yielded better performance (R2 = 0.62, RMSE = 0.63, R2/RMSE = 0.98) compared to the use of each image separately. Therefore, this study concluded that the simultaneous synergy of remote sensing data from different sources (referred to as data synergy) can significantly improve the accuracy of predicting soil organic carbon content in calcium-enriched agricultural soils in the central region of Iran. It is recommended to use advanced fusion techniques and deep learning methods for combining features at a higher level.

The behavior of heavy metals in the soil as one of the environmental challenges has attracted the attention of many researchers. The present study was conducted to evaluate the phosphorus solubilizing bacteria on remobilization of cadmium (Cd) and lead (Pb) in two calcareous soils.

Phosphorus, cadmium and lead in the forms of KH2PO4, Cd(NO3)2 and Pb(NO3)2 simultaneously were introduced to the soils to promote the formation of phosphate minerals of added metals in two selected soils. Ater two months the soils were inoculated with two Pseudomonas species and incubated for 3 months. Sequential extraction scheme were applied to determine the chemical forms of Cd and Pb 5, 25, 60 and 90 days after incubation.

The results showed that application of phosphorus solubilizing bacteria changed chemical forms of Cd and Pb. Inoculation with Pseudomonas decreased the soluble and exchangeable cadmium while increased organic matter-bound Cd concentration. Inoculation by Pseudomonas increased carbonate-bound Pb and decreased Fe-Mn oxide and organic matter bound Pb. In the other hand, phosphate solubilizing bacteria (Pseudomonas) decreased mobility and bio-availability of cadmium and immobilization of lead.

In fact, the behavior of heavy metals in the presence of phosphorus solubilizing bacteria was different and depends on the type of metal and soil properties. In present study, bacteria cause immobilization of cadmium and remobilization of lead.

Recent researches have proven the effect of salinity of water and soil resources on the bioavailability of cadmium.In this study, the effect of different sources of salinity including sodium chloride, sodium sulfate and calcium chloride on cadmium transport in two different soils was investigated.Soil columns with a height and inner diameter of 50 and 10 cm, respectively, were subjected to leaching of cadmium solution at a concentration of 100 mg/L along with various salts of sodium chloride, sodium sulfate and calcium chloride at a concentration of 100 me/L for 10 days. The drained solutions were analyzed at three depths of 3, 7 and 50 cm. The simulation of cadmium chemical species in the soil solution was performed using Visual MINTEQ 3.The presence of salinity along with cadmium solution caused more transport and drain of cadmium than the control soil. The highest cadmium concentration drained from the columns was belonged to the soils which received calcium chloride with the mean of 19.6 mg/L whereas the lowest was determined in soil received sodium sulfate with the mean of 6.1 mg/L. Due to the formation of chloro-cadmium complexes, treatments containing chloride had a more obvious effect on the transport of cadmium in the soil columns. The simulation of cadmium speciation in solution containing chloride showed that CdCl+ and CdCl2(aq) account for more than 80% of the cadmium species, while in those containing sodium sulfate, this dominant mainly included two species of Cd(SO4)2- 2 and Cd(SO4)(aq). Generally, salinity conditions affected by chloride ions in cadmium polluted lands can increase the potential of this toxic metal entering water sources and food chain.

The presence of abundant calcium carbonate and alkaline soil reaction in most of the country's soils has reduced the bioavailability of some elements for plants. The application of some soil amendments such as sulfur and organic matter can improve the nutrient status of the soil. For this purpose, a factorial experiment was conducted in a randomized complete block design with 18 treatments and 3 replications on the underground soil of walnut trees. The experimental factors included Thiobacillus at two levels (without inoculation and with inoculation), sulfur (S) at three levels (0, 1000 and 2000 kg. ha-1 ) and organic matter (OM) at three levels (0, 5 and 10 T. ha-1 ). The results showed that S treatment significantly affects soil pH (p <0.01), P (p <0.05) and iron (Fe) concentration on soils beneath the tree covers (p <0.05). The highest P concentration (9.06 mg / kg) and available Fe (6.34 mg / kg) was observed in the treatment of 2000 kg. ha-1 of sulfur. Organic matter treatment significantly has changed the soil pH (p <0.01), available Zn (p <0.01) and plant available P and Fe concentration in soils beneath the tree covers. As the level of applied OM increased, the soil pH decreased. The highest concentration of available P, Fe and Zn was observed in the treatment of 10 tons per hectare of OM. Inoculation with Thiobacillus bacteria decreased the soil pH and increased soil available P concentration. According to the results, the simultaneous application of S, Thiobacillus and OM can increase the phytoavailability of P, Fe and Zn in soils beneath the walnut trees.

Purpose This study performed a feasibility assessment of nitrogen enrichment by some organic wastes through vermicomposting as well as its release as a bioavailable form over time. Methods Soybean and canola wastes as well as the dairy blood powder of industrial slaughterhouse were used as organic wastes to enrich the vermicompost. Composted materials were incubated for nitrogen mineralization kinetic assessment by adjusting moisture content to 50% at 30 ˚C for 80 days. During the incubation, moisture was maintained by weighing. Subsamples were collected after 1, 5, 10, 20, 40, 60, and 80 days of incubation. Results Among the treatments, those for 25% dairy blood powder contained the highest nitrogen content (4.95 and 3.70% for chicken and cow blood powder, respectively). Nitrogen mineralization through 80 days of incubation ranged from 2.23% (for 50% canola waste treatment) to 2.57% (for 25% blood powder) of the total nitrogen. The mineralization rate ranged from 4.24 and 3.62 mg kg-1 day-1 for the compost containing 25% chicken and cow blood powder, respectively, to 0.94 and 0.84 mg kg-1 day-1 in canola and soybean waste, respectively, whereas those for the control treatment equaled 0.81 mg kg-1 day-1. Conclusion Composts containing 25% blood powder were acceptable in terms of quantity and nitrogen release over time, and can serve as a reliable source of available nutrients in the soil.

Environmental implications of cotinious application of chemical fertilizers, while ongoing demands for healthy products has made the attentions to the sustainable agriculture. Integrated soil nutrient management inclouding part replacement of chemical fertilizers by biofertilizers is among the sustainable agriculture nesseserities in recent years. Varius biofertilizers aleady are producing or importing into Iran's market. This study was conducted to evaluate the efficiency of some biofertilizers with brand names Multifunctional, Bioumik, Fulzyme plus, Nitrokara, Golden Nitrokara and Inoculum on morphological characteristics and concentration of nitrogen (N), phosphorous (P) and potassium (K) of peppermint plant. A greenhouse experiment was conducted with five replications. Four plants was grown in pots containing 5 kg soil treated with 2% w/w solution of biofertilizers, two times during growing period. Results showed that biofertilizers had significant effect on the number of leaves and stems, root fresh weight, as well as shoot P and root and shoot N. The highest effect on root and shoot N (1.49 and 2.26%) and shoot P (1.18%) were related to Bioumik and Nitrokara, respectively. Nitrokara efficiently resulted in increased shoot P, which was significantly higher than the other treatments. According to the results among biofertilizers best N nutrition and number of leaves was with Bioumik while lowest shoot P was observed in this treatment.

To investigate simultaneous effects of Thiobacillus bacteria, sulfur, and organic fertilizer treatments on chemical forms and quantity of phosphorus absorption by corn, an experiment was conducted based on completely randomized design using eight treatments and three replications in a greenhouse located in Hashtgerd, in 2014. Treatments included control, Thiobacillus, sulfur, organic fertilizer, and two ways and three ways combinations of these factors. Results showed  that the highest and lowest yield, root dry weight, root fresh weight, shoot weight, and phosphorus uptake were obtained in the Thiobacillus + sulfur +organic fertilizer treatment and control treatment (without any added Thiobacillus, sufur, and organic fertilizer), respectively. Thiobacillus + sulfur +organic fertilizer treatment caused significant change in inorganic and organic phosphorus elements and enhanced available phosphorus in soil, so that the highest available phosphorus was related to the treatment number eight with 16.22 mg/kg soil and this treatment showed four more mg of available phosphorus compared with control treatment. On the other hand, the Thiobacillus +sulfur treatment resulted in more reduction in mineral forms of phosphorus including dicalcium phosphate and apatite joint phosphorus compared with other treatments. The most organic and total phosphorus in soil was observed in sulfur + organic phosphorus and Thiobacillus + organic phosphorus treatment, respectively. Taken together, results of this study showed that using Thiobacillus bacteria along with sulfur and organic fertilizer would result in enhanced phosphorus uptake and improved phosphorus status in the plant, which would cause more reduction in chemical fertilizers in extensive scale.