Effect of Soil Characteristics and Rotation Type on Concentration of Cadmium in Soil

Contamination of water and soil to the heavy metals (Cadmium) is one of the major environmental problems the communities. So it is particularly important to consider factors in order to manage the cadmium concentration in the agricultural products and enhance the human health. Thus, performing such study to find out the soil characteristics contribution and practice various plantations (rotation) on soil cadmium concentrations is very necessary. The objectives are to :( i) determine the relation of soil properties with the amount of cadmium existing in soil, (ii) specify the impact of rotation on concentration of cadmium present in soil and (iii) identify the most appropriate type of rotation that affect on cadmium concentration quantity in soil at the farms located in south and north of Shushtar region. Three dominated rotations were selected: wheatmaize- wheat, wheat-rice-wheat, and wheat- vegetable-wheat. Then, at the beginning of crops cultivation, (three rotations, three fields in both regions), 18 soil samples were taken. At the end of farming period, the number of 18 samples was prepared as well at the same fields. The results showed that the total cadmium concentration in the soil was higher than the limit of 1.8 mgkg -1 , whereas the available cadmium in over 9% of the study soil was higher than 0.1 mgkg -1 . Also, the amount of elements’ concentration, that is, the iron and zinc in more than 70% and 60% of the study soils respectively were lower than allowable limits. The results indicated that the rotations in the region such as ricewheat, maize-wheat, and legumes- wheat have had an influential contribution on nutrient concentration as well as some other soil characteristics. However, they had no significant impact on total concentration change and available cadmium of the soil.