Micronutrients in Soils, Plants, Animals and Humans

摘要

Micronutrients play a key role in growth and development of plants, animals and humans. Micronutrients namely, zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), boron (B), molybdenum (Mo), chlorine (Cl), nickel (Ni); cobalt (Co) for legumes only, essential for plants are also essential to human. Iodine (I), selenium (Si), fluorine (F) and chromium (Cr) are essential for human but not for plants, but absorbed by plant from soil and water and enter into the animals and humans through food chain. Micronutrient application has not only contributed in enhancing the food grain production but also helped in sustaining soil health and fortifying the country's nutritional security. As per the GPS-aided analysis of more than 2 lakh soil samples, element-wise deficiency is as follows: Zn 36.5%, Fe 12.8%, Cu 4.2%, Mn 7.1%, B 23.4%. Scattered deficiency of Mo has been observed in acid soils. Food and fodder produced on these soils without supplementation of deficient micronutrient(s) have poor trace element concentration, causing micronutrient malnutrition in animals and humans alike. Even though the levels of trace elements like Cu, Zn, Mn, Fe, Mo, Se and Co in crops are sometimes sufficient for optimum yields but they are sub-optimal to meet the needs of livestock leading to their widespread deficiencies. Widespread nutritional deficiencies of vitamin A, Fe, Zn, and iodine affecting human health, disproportionately especially women and young children, have been reported. Soil-related deficiencies of trace elements such as Se, Cu, Fe and Zn are also implicated as causal factors for anemia. Toxic concentrations of some trace elements in soils also adversely affect the animal and human health. For correcting micronutrient malnutrition in animal and human, the strategies of micronutrient management should focus on enrichment of these elements in edible plant parts and making them bioavailable without compromising on the sustenance of crop production. Holistic approach is required to develop sustainable technologies to reduce micronutrient malnutrition by launching a mission mode programme on micronutrient research in soil-plant-animal/human continuum mode.