The Selections Of Soil-passivation And Low Accumulation Rapeseed In Siqiandaba Field,Guizhou Province

Mercury?Hg?would cause serious harm to the local ecological environment and human body,but it was not very clear how much the mercury was in the soil so far.Moreover,there are still difficulties in the treatment and utilization of soil was polluted by mercury.90 oilseed rapes?Brassica napus L.?and the corresponding soil samples were gathered from Siqian farmland.The amounts of Hg in oilseed rapes and the corresponding soil samples were analyzed.The bioaccumulation factor?BAF?and translocation factor?TF?of Hg were also calculated.The reaction details between sodium sulfide,sodium selenite,organic fertilizer,biochar,bentonite,zeolite and mercury were studied.The oilseed rapes which have tolerance and low-accumulation of Hg were selected from 10 varieties.The main results obtained in this study are:?1?The amounts of Hg in soil of Siqian have a relatively clear relationship with their geographical location.The region were divided into three areas:0?200m,200?400 m,and more than 400m from Wawu River.The results show:the ratios which represent the amounts more than 10.9 mg·kg^-1 of three areas was69.4%,38.5%,and 6.7%.The bioaccumulation factor?BAF?of Hg in the rape roots,stems and grains was 0.263,0.404 and 0.026.The translocation factor?TF?of Hg in the rape stems and grains was 1.68 and 0.10.The grains of rapes had a strong resistance to the absorption of mercury.?2?The best passivators and dosage are sodium sulfide(50mg·kg^-1),sodium selenite(3mg·kg^-1),organic fertilizer(10g·kg^-1)and bentonite(50g·kg^-1)in this area.The p H of soil was most affected on the 7th day by the immobilizations,however,there was almost no effect on the other time.The p H differences between sodium sulfide(200mg·kg^-1),sodium selenite(3mg·kg^-1),organic fertilizer(10,20,50 g·kg^-1)and the clean soil on the 7th day was more than 0.2 units.?3?The yields of Nanyou No.12,Xinanyouba,Jinyou No.8 and Ningza No.11had exceeded 14 grams each plant.All the BAF of Ningza No.11,Deyouza No.11and Xinanyouba were less than 0.023.Xinanyouba and Ningza No.11 were the best varieties which had high yields and low-accumulation of Hg.In conclusion,the amounts of Hg in soil could affect the amounts of Hg in the grains.The immobilizations and the varieties of low-accumulation can effectively reduce the risk of planting in mercury-polluted soil.