Study of the effects of land use change and construction of sugarcane fields on physicochemical, mineralogical and micromorphological characteristics of soil in southern Khuzestan province

sugarcane cultivation with unique conditions for growth such as long growth season, higher water demand and using the heavy agricultural machinaries in different stages of the sugarcane cultivation can affect on soil properties and soil resources. The present research aims are physicochemical investigation and study of clay mineralogy and micromorphology properties of soils under sugarcane cultivation in comparison with noncultivated soils.
Study area is located in fields of the Amir Kabir Agro-industry company about 45 km south of the city of Ahvaz on river alluvial plains. The soil moisture and temperature regimes are Aridic and Hyper thermic, respectively. At first, all field sheets of agro-industry are checked and then four fields are selected without any limitation and with more than 15 years sugarcane cultivation. Four profile was described in fields and its nearby uncultivated land (distance of approximately 30 meters from field) and were sampled according to conventional procedures. The physicochemical properties consist of available K, organic carbon, CEC and particle size distribution were determined. Also, mineralogical and micromorphological properties of samples were determined and All data were statistically analyzed using the SPSS 2012 software program and then results were compared.
The results of this survey indicated that land use change and cultivation operation in non-cultivated regions have not high quality can change some properties of soil quality; But the severity of these changes were not the same for different soil characteristics. Some properties were changed in cultivated soils such as EC, available K and particle size distribution. In this study, no significant difference was seen between pH amount from land use change that can be attributed to the high buffering capacity of the soil and the high levels of carbonates in Khuzestan soils. Long-term cultivation result important changes in the clay minerals in sugarcane fields that majority of these changes are refered to mineral conversion and K element. Expandable 2:1 minerals were observed under sugarcane cultivated especially in surface horizons that are attributed to reduction in the amount of palygorskite and illite. Micromorphological study of thin sections of descripted horizons indicated aggregation with weak pedality in some cultivated soils. Also, In most descripted horizons of profiles in cultivated fields, the percentage of pores increases . The comparison between cultivated soil and noncultivated lands indicated thad there is no difference between them aspect of classification and land use change did not affect on soil family. This research showed that intensive cultivation and heavy irrigation cause alteration in mineralogy and element requirement changes of soils.
Conclution: Land use change cause some basic changes in physicochemical, mineralogical and micromorphological properties of soil in sugarcane fields.