论文部分内容阅读
The leaching characteristics of a garden soil may be greatly affected by application of poultry and livestock manures from intensive farming.Packed soil columns of a garden soil (CK) and the soils after respectively receiving 2% pig manure (PM),chicken manure (CM),and commercial organic manure (OM) were leached with 0.05 mol L~(-1) Ca(NO_3)_2 and 0.01 mol L~(-1) EDTA solutions.The leachate EC (electric conductivity) values gradually increased at the beginning and then reached a stable value when the soil columns were leached with 0.05 mol L~(-1) Ca(NO_3)_2 solution.The leachate EC values showed a peak-shape when leached with 0.01 mol L~(-1) EDTA solution.In all the soil columns,the pH values of the leachates decreased with increase of displacement volumes when the Ca(NO_3)_2 solution was used.The total amounts of Cu and Zn eluted from the four soil columns were significantly correlated with the extracted soil Cu and Zn concentrations by 1.0 mol L~(-1) NH_4NO_3,but were not correlated with the leachate dissolved organic carbon (DOC) contents.The Zn concentration in the leachate of the PM-treated soil column with 0.05 mol L~(-1) Ca(NO_3)_2 solution was above the Quality StandardⅢfor Ground Water of China (GB/T 14848-93,Zn<1.0 mg L~(-1)).When compared with 0.05 mol L~(-1) Ca(NO_3)_2,the EDTA solution significantly accelerated Cu and Zn elutions in the manure-treated columns.This suggested that applying poultry and livestock manures from intensive farming to farmland might pose a threat to the groundwater quality.
The leaching characteristics of a garden soil may be significantly affected by application of poultry and livestock manures from intensive farming. Packed soil columns of a garden soil (CK) and the soils after respectively receiving 2% pig manure (PM), chicken manure (CM ) and commercial organic manure (OM) were leached with 0.05 mol L ~ (-1) Ca (NO_3) _2 and 0.01 mol L ~ (-1) EDTA solutions. and then reached a stable value when the soil columns were leached with 0.05 mol L ~ (-1) Ca (NO_3) _2 solution.The leachate EC values showed a peak-shape when leached with 0.01 mol L ~ (-1) EDTA solution .In all the soil columns, the pH values of the leachates decreased with increase of displacement volumes when the Ca (NO_3) _2 solution was used. The total amounts of Cu and Zn eluted from the four soil columns were significantly correlated with the extracted soil Cu and Zn concentrations by 1.0 mol L ~ (-1) NH_4NO_3, but were not correlated w The leachate dissolved organic carbon (DOC) contents.The Zn concentration in the leachate of the PM-treated soil column with 0.05 mol L -1 Ca (NO_3) _2 solution was above the Quality Standard Ⅲ for Ground Water of China (GB / T 14848-93, Zn <1.0 mg L -1). When compared with 0.05 mol L -1 Ca (NO 3) 2, the EDTA solution significantly accelerated Cu and Zn elutions in the manure-treated columns .This suggested that applying poultry and livestock manures from intensive farming to farmland might pose a threat to the groundwater quality.