Due to food security concerns following population growth and as well as the global warming catastrophe, efforts to expand biochar-related research are being raised. Biochar is a solid and carbon-rich material produced by pyrolysis processes, considered for carbon sequestration as well as a kind of soil remediation in recent years. The propose of this study was to overview the effects of different modifier materials on soil chemical and physical properties, plant growth and yield, modeling phosphorus uptake with NST 3.0 model and uncertainty analysis of the model. The study performed in four parts. 1) determining chemical and physical properties of raw materials including poultry manure and corn residues and their production biochars at two temperatures of 350 and 650 °C. With increasing pyrolysis temperature, pH, EC and the percentage of equivalent calcium carbonate (CCE), phosphorus, potassium and total sodium also increased. Bulk and particle density, porosity and repellency were the measured physical properties. In the second study, the above materials were added to a sandy loam soil with a ratio of 1, 2 and 4% (w/w) and some characteristics of corn cultivated in these soils were measured. The chemical and nutritional characteristics of the treated soils were determined in the second study and physical and hydraulic properties in the third study. The highest yield and leaf area of the plant was observed in the raw corn residue treatments. The results of the third study showed that the addition of modifiers, especially raw materials and biochars at 350 ° C, increased soil organic carbon, reduced amount of dispersible clay and increased soil structural stability (by water stable aggregates, WSA, and high energy moisture characteristic curve, HEMC) especially in the group of corn residue and its biochars. Differences in water retention in treated soils were observed in all soil matric suctions, although these differences were more pronounced in low suctions. The values of soil physical quality indices were affected by pyrolysis temperature and type of modifiers. Most of the treated soils, especially with the corn residue group and its low temperature biochars, had very good physical quality (investigated with S1 index). The type and amount of modifiers and the pyrolysis temperature significantly affected the least limiting water range (LLWR) and integral water capacity (IWC) quantities. The positive and significant correlation of these quantities expressing S1 and S2 indices as proper indicators of physical quality of the soil. In the fourth study, the arrangement of the treatments was based on the concentration of 50 and 100 mg P/kg soil of KH2PO4 fertilizer and other modifiers of previous studies. The purpose of this study was to eva‎luate the uptake of P per unit of root length (cm) in different treatments. Estimated uptake by NST 3.0 model was lower than actual uptake in most treatments (low estimate) but approached to the measured value with considering the root hairs. The highest differences between the model estimates and the measured values were observed in the CR50 and CR100 treatments. The results of uncertainty analysis of NST 3.0 model using Monte Carlo algorithm, Markov chain were presented in the fifth study. The most sensitive parameters of the model according to this analysis were the phosphorus concentration in the soil solution (CLi) and the buffer power index (b), while the Michaelis constant (Km) had the lowest sensitivity among the other parameters. All observed uptake data, except the corn residue treatment at 100 mg P/kg (CR100), were in the total uncertainty band, which indicates that these data can be trusted. In general, according to the results of this study, it is suggested that utilizing poultry manure or corn residues biochar produced at 350°C, at the rate of 1 or 2% is useful for managing soil water and increasing soil physical, chemical and fertility quality

محمد علي حاج عباسي، حسين شيراني

مجيد افيوني، محمدرضا مصدقي، نوبرت كلاسن

مهدي شريفي، محمد شايان نژاد، حسين شريعتمداري