Changes In Fractions Of Fluoride In Calcareous Soil And The Influence Of Fluoride On The Growth, Yield And Quality Of Maize

Calcareous soil are widely distributed in chief agricultural areas of China. The state and transform of nutrient elements are important to plant nutrition and environmental quality in calcareous soils. Fluorine is a necessary element for life of human and animals. Abnormality of fluorine in eviroment always results in human and animals fluorine poison. For animals, too much fluorine has bad influence for their health. This paper studied form classes of fluoride in calcareous and its influence to maize's growth, development and yield quality by tests on pot cultivation on the basis of investigation on movement transformation of fluoride in the system of atmosphere-soil-plant in polluted regions. This study presents theory proof to efficient prevention and comprehensive management on fluorine pollution in soil. The effects are as following:1. Fluorine's existing from in calcareous soil as arranged according to its content as: remains forms> dissolvent forms> combination of Fe and Mn forms> organist bit forms >alternative forms. Fluorine of remains form is the main form. Fluorine of remains form is the main body of whole fluorine consistence, accounting for over 90%, Contents of each fluorine form and whole fluorine content have a significant relevance, and will increase with increase of treatment concentration, remains form increase with extension of breeding period fluorine of while the other forms all decline with the extension.2. After fluorine treatment is implemented to calcareous soil PH of soil. Content of organism are improved, content of dissolvent Ca2+ drops significantly, soil microorganism is influenced to diffident extents.3. Fluorine can decline maize's growth seriously especially biological quantity above earth in young plant period, decline of drop weight is 22.5-42.0%. With extension of breeding period, jointing stage and boot stage decline as 4.7-43.3%, so fluorine treatment of high as concentration (F4.F5) restrain crops persistently, while fluorine treatment of low concentration has obtuse function, it can influence crops significantly accumulative With the extension of breeding period.4. Fluorine has obvious restrictive function to maize's root system, and the function improves with the extension of breeding period. Fluorine of low concentration induce enhancement on activity of SOD...