Accumulation Of Heavy Metals In The Environment Of Different Pig Raising

With the development of intensive and scale livestock farming, effect of animal manure on soil environment increasing people’s attention. The heavy metal is one of the main pollutants in livestock manure, manure directly discharged to the environment, heavy metals become limiting factors of soil health; Bio-bed, is a newly developed pig-raising system, which theory is microbial decomposition of litter in livestock manure to reduce direct emissions on the environment, it is important to reduce heavy metal contaminated in soil. A study was performed to determine the effects of bio-bed pig raising on heavy metal content in bio-bed materials at different stages, in soil under the bio-bed, and in soil out of bio-bed, using soil from the traditional pig raising in the same location as reference. After 1-year study, discuss accumulation of heavy metals on bio-bed material, to investigate the properties of heavy metal accumulation in bio-bed material, provide a reference for the later use of the bio-bed material; heavy metals in soil samples studied content changes over time through bio-bed and traditional large-scale farming pig outside, impact assessment of heavy metals in the soil environment bio-bed farming and traditional large-scale farming. Aims to provide a reference for the popularization of bio-bed, environmental assessment and use of bio-bed material. Get the main conclusions are as follows:(1) Breeding manure of bio-bed pig raising heavy metals are mainly concentrated in the bio-bed material, Cu、Zn、Cr、As、Pb、Ni、Cd、Mn in 0～40 cm in the cumulative amount of bio-bed material contents were 50.81,84.32,36.08,7.25,12.12,65.99,2.79,2343.68mg·kg-1, lower for under bio-bed material Soil.(2) Bio-bed material by a year of use, Pb, Cd exceeded the maximum content of organic fertilizer by the state, Subsequent use abandoned bio-bed material through add conditioner, compost, etc. Bio-bed material dilution of heavy metals can be used after the bio-bed material harmless.(3) Bio-bed pig raising will cause the accumulation of heavy metals in the soil outside, 0-80cm soil Cd levels have exceeded the national standard three soil content, planted in the soil of the crop there are some security risks, Ni exceeded the national standard two soil, not yet reached the standard value three levels of the soil, there is within the safe range.(4) Similar to the soil outside of bio-bed pig raising, Cd in traditional pig raising soil exceeded the national standard three levels soil content, Ni exceeded the national standard two soil, standard values have not yet reached three levels of the soil, It is still in a safe range.(5) After a year of trial period,20～80 cm soil in bio-bed pig raising of Cu, Zn, Cr, As, Pb, Ni, Cd, Mn, respectively the cumulative amount 7.42,16.83,0.69,2.05,8.07,33.66, 1.09,269.03mg·kg-1; traditional pig raising outside the cumulative amount of soil samples respectively 34.45,55.31,45.41,3.58,25.29,37.81,2.12,591.71mg·kg-1. Heavy metal content of traditional pig raising outside the heavy metal accumulation were higher than the bio-bed pig raising outside cumulative, Description bio-bed pig raising in terms of heavy metal pollution in the soil environment to be lower than the traditional pig raising, for ease of livestock farming on soil heavy metal pollution effect is remarkable.