ramazanali dehghan

The present study was conducted to investigate changes in soil physical and chemical properties and organic carbon storage at different stages of sugarcane growth (Plant, Ratoon 1, Ratoon 2, Ratoon 3, and Ratoon 4) in some sugarcane plantations in southern parts of Khuzestan Province, Iran. For this purpose, a number of soil profiles were dug in the sugarcane fields and 30 sites were selected and studied in a completely randomized design with five treatments (i.e. sugarcane growth stages) and six replications. The results of this study showed that long-term cultivation of sugarcane and different stages of growth in soils of Sugarcane Cultivation and Industry Company caused changes in physicochemical properties and soil carbon storage. Indeed, abundant irrigation and leaching and cultivation management of sugarcane reduced the salinity and sodium in soil solution. Also, different growth stages changed the physical and chemical properties of the soil. Different stages of sugarcane growth reduced electrical conductivity (EC), dissolved sodium in the soil, the available potassium (K), and increased the amount of bulk density (Bd) in the soil. There was no significant difference in the amount of organic matter (OM) and soil acidity (pH) of sugarcane fields at different stages of growth. Finally, in order to prevent possible negative consequences and depletion of soil nutrients, especially potassium, it is necessary to periodically study the complete properties of the soils and evaluate these changes, appropriate management methods can be performed to maintain soil quality. The results showed that difference in soil carbon sequestration was significant (p<5%) in the treatments, such that the highest carbon sequestration was in Raton 3 (28.84 tons/ha) and the lowest in Raton 4 (15.50 tons/ha). The reason for the higher amount of carbon storage can be attributed to more vegetation and, therefore, more plant debris, which reduce evaporation from the soil surface, a positive effect on vegetation, especially in arid and semi-arid regions. In general, optimal management of sugarcane fields plays an important role in improving atmospheric carbon sequestration capacity.

The purpose of this study was to investigate the effect of soil characteristics on sugarcane yield and to revise the “Table of Soil and Landscape Requirements for Sugarcane”. For this purpose, 120 points in different areas under sugarcane cultivation in Khuzestan and Mazandaran provinces were studied based on diversity in soil characteristics. Parametric methods were used in this study to determine the land index. For data analysis, multivariate regression by stepwise method and simple regression were used. Sugarcane yield was considered as a dependent variable and factors including salinity, percentage of exchangeable sodium, soil acidity, gypsum, lime, clay, sand and silt, as independent variables. Then, by examining the simple regression between important and effective land characteristics with sugarcane yield, the relevant equations and diagrams were drawn and soil properties were rated by FAO method. The results showed that exchangeable sodium, clay, lime, acidity, and salinity, in decreasing order, had a significant correlation with yield of sugarcane, while and the variables of sand and silt had no significant correlation. Multivariate regression coefficient analysis showed that the variables entered in the model were able to explain 67% of the variance related to the dependent variable. In simple regression equations, soil salinity, exchangeable sodium content, and lime had a decreasing effect on yield. The variables of exchangeable sodium percentage and soil salinity had the greatest effect on sugarcane yield. The proposed table on sugarcane soil and landscape requirements was evaluated and validated by using soil data and yields of 30 sugarcane fields that had not been used to extract this table. The coefficient of determination between the sugarcane yield and the land index was about 0.81, indicating the acceptable accuracy of the table.