Effect Of Calcium Peroxide On Remediation Of Continuous Cropping Soil Of Panax Notoginseng

The continuous cropping obstacles had effected the quality of Panax notoginseng seriously and restricted the development of the industry chain in Yunnan. Now it has became a hot and hard point to remediate the unsuitable soil, improving the properties of physical and chemical, the quality of mineral nutrition, and microbial community structure, then the Panax notoginseng can survival. Calcium peroxide is a environmental friendly material, and as the properties of oxygen releasing and alkalinity, calcium peroxide has used in soil remediation.By adding calcium peroxide to the soil, we designed soil cultivation experiment and pot experiment, and aimed to study the effect of calcium peroxide on the soil, including properties of physical and chemical, the quality of mineral nutrition, microbial community structure, seed germination, and seedling emergence. When calcium peroxide added, p H of soil increased, the more added the more increased. As the different buffer capacity, the increase amplitude of p H in different soils are different. When 5g·kg^-1 calcium peroxide added, compared with the background values of p H, the highest values in different soils were increased 0.97、1.2、1.5、2.1、1.8、1.1（soil Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ）. In the 5th day, quality of NO3--N in treatments was lower than the control, as time going, quality of NO3--N in treatments was higher in the middle-later period. When the background value of p H was 5.8-6.0, quality of NH4+-N in treatments was higher than the control in experiment period; when the p H value was higher, the treatments excessed the control in the 20 th day. When the quality of calcium peroxide added over 5 g·kg^-1, available potassium and water-soluble magnesium reduced to lower than the control, and slowly available potassium increased to higher than the control. While the quality of calcium peroxide added was 0.5、2.5、5 g·kg^-1, available manganese came down gradually as the quality of calcium peroxide added raised. However, when 10 g·kg^-1 calcium peroxide was added, available manganese dropped to lower than the control. The change of EXC-Mn in soil showed two situations, one was the quality of EXC-Mn in treatments decreased when the background value was high, the other was increased when the background value was low. The quality of available iron dropped as calcium peroxide increased. Compared to the continuous cropping soil, p H and slowly available potassium in the raw soil increased in higher scope.Calcium peroxide can improve the structure of microbial community and was helpful for soil to transform to bacterial forms.Seed germination of Panax notoginseng was depressed as the addition of calcium peroxide. Seedling emergence of Panax notoginseng was also depressed while 5 g·kg^-1 calcium peroxide added, but, while the quality of calcium peroxide was 2.5 and 10 g·kg^-1, seedling emergence was speeded.