Monitoring of iodine in the soil - plant system (review)

Iodine plays an important biological role in live organisms. It participates in many physiological and biochemical processes and has more impact on the growth, development and efficiency of the plants. At the deficiency of the microelement in an ecosystem the animals and the man have various endemic diseases. The main source of the intake of iodine to the soil and plants is the World Ocean. The contents level, the mobility, accumulation and migration of iodine depend on the land relief, agrophysical and agrochemical properties of soils and soil making rocks, vegetation, climate, geomorphology and hydrological mode. The behavior of iodine in the structure of soil cover of agrocenosis is defined by the properties of metal and soils fertility. Their humus state, acidity and particle size distribution have the impact on the content of iodine in the soils. The smallest amount of iodine is noted in sour podsolic and gray forest soils, easy particle size distribution and the greatest is in saline soils. Calcareousness of soils and alkaline reaction of the environment reduce the mobility of halogen in the soils and promote the formation of a large number of almost insoluble compoundings. Washing and periodically washing mode strengthens the migration of the microelement on the profile of the soils. Average content of iodine in the soils fluctuates from 0.2 to 12.0 mg/kg at the background value of 5 mg/kg. In regional conditions the concentration of iodine in the soils is influenced by the property of soils, soil formation conditions, weather conditions and the properties of halogen. The plants are characterized by unequal content of iodine. Major factor of the accumulation of iodine in plants is the security of soils with a mobile form of an element, specific and high-quality features of crops. Average content of iodine in the plants is in the range from trace quantities to 2.50 mg/kg of solid. In vegetable production of many regions of the country the deficiency of iodine is observed. The optimization of plants nutrition iodine requires using iodic fertilizers. Under the influence of these fertilizers the element structure and efficiency of crops raise.