三、 Affect the factors of redox 1. Activity of microorganism 2. Content of labile organic matters 3. Content of easy oxidation-reduction inorganic matters in soil 4. Metabolism of plant roots 5、 Soil ph value1．Activity of microorganism 2．Content of labile organic matters 3．Content of easy oxidation-reduction inorganic matters in soil 4． Metabolism of plant roots 5．Soil pH value 三、Affect the factors of redox