| This paper focuses on the effects of earthworm dung and humic acid on the remediation of heavy metal contaminated soil.The effects of heavy metals Pb and Cr on the chemical properties of heavy metals are studied by applying different proportions of earthworm dung and humic acid.In order to discuss the improvement of heavy metal lead and chromium contaminated soil and the feasibility of planting lettuce and junda,this experiment adopts pot experiment in greenhouse,and adopts soil planting lettuce of sewage pollution Pb pollution in Jinyuan District of Taiyuan City.This soil planting junda of the Cr-contaminated soil irrigated by the sewage irrigation in the village of Liujian,Taiyuan City.he experiment is divided into two Parts:Studying the earthworm dung was applied in different amounts of humic acid,and the Pb、Cr contaminated soil were used as the research object.The pot experiment was used to study the two kinds of modifiers according to different contents(earthworm dung: 100g/kg,300g/kg,humic acid:10g/kg,20g/kg,30g/kg)applied to Pb contaminated soil p H,total nitrogen,organic matter,alkali nitrogen,available p Hosp Horus,available potassium,total phosphorus,total potassium,heavy metal Pb and Pb content in lettuce and the effect of lettuce yield,heavy metal Cr and Cr content in junda and junda yield.The effect of(Cr)content and lettuce yield.promote Agricultural Development.The results show:(1)The effects of different levels of earthworm dung and humic acid on the chemical properties of Pb-contaminated soil were different.The effects of arthworm dung and humic acid had no significant difference in p H of soil and tends to be neutral.When the content of humic acid was 300+30,the organic matter content was the highest,which increased by 344.50% compared with the control.The organic matter was humus the acid content increases and increases.(2)The content of total nitrogen and alkali nitrogen in Pb-contaminated soil increased significantly with the increase of earthworm dung and humic acid content in manure,which was significantly different compared with the control.The total nitrogen and alkali nitrogen content of the treatment under 300+30 treatment was the highest,which was 48.42% and 128.38% compared with the control.Compared with the control,the available potassium and total potassium in Pb-contaminated soil decreased by 29.73~50.38% and 0.9~16.27%,respectively,with significant difference(P<0.05).The increase of humic acid content in cockroach will decrease the content of available potassium,but the content of total potassium will increase.The effect of available potassium and total potassium in the application of 300+10 is more obvious.The application of sputum humic acid significantly increased the available phosphorus and total phosphorus content in lead-contaminated soils compared with the control.However,there was no significant difference in total phosphorus content between treatments.When the manure is 300g/kg,the effective phosphorus content is high,and the effect of 300+10 on the effective phosphorus is the best.(3)The application of earthworm dung and humic acid affects the Pb content in Pb-contaminated soil and lettuce.Compared with CK,the application of sputum humic acid increased the Pb content in the soil,and the difference was significant(P<0.05).Applying earthworm dung and humic acid will increase the lead content in the soil and play a good role in fixing the Pb content.Compared with the control,the Pb content in lettuce decreased significantly from 25.05 to 79.01% with the increase of earthworm dung and humic acid.When the content of earthworm dung and humic acid is fixed,the content of earthworm dung increases,and the Pb content in lettuce decreases,which increases the migration ability of heavy metals.In the Pb-contaminated soil,the content of humic acid in the manure increased,and the yield of lettuce was not significantly increased compared with the control.At 300+30,lettuce yield was the highest,an increase of 39.4% compared to the control.(4)The effects of different levels of humic acid on the chemical properties of Cr-contaminated soil were different,and the p H did not change significantly with the increase of humic acid content.Compared with CK,the application of sputum and humic acid significantly increased the organic matter content of chromium-contaminated soil.When the humic acid content was 30,the organic matter content increased significantly,which was 154.41% higher than that of the control.The organic matter content increases with the increase in the content of humic acid in the manure.Compared with CK,the addition of earthworm manure and humic acid had an inconsistent effect on increasing total nitrogen and alkali nitrogen content in Cr-contaminated soil.When the total nitrogen content is 300+30,it increases by 115.93% with CK.The content of alkali nitrogen was significantly increased when the humic acid content was increased to 20 g/kg when the humic acid content was 100 g/kg.Compared with CK,the application of sputum humic acid increased the content of available potassium and total potassium in Cr-contaminated soil,and the difference was significant(P<0.05).When humic acid is increased,the available potassium content is significantly reduced.Between the treatments,the application of sputum humic acid had no significant effect on total potassium in the soil.The content of available phosphorus in humic acid was significantly higher than that in CK,and the difference was significant(P<0.05).The differences between the treatments were significant.When the earthworm and humic acid are 300+20,best effect.(5)Compared with the control,the Cr content in the Cr-contaminated soil increased significantly,and the difference was significant(P<0.05).At 300+30,the content is the highest,and the Cr content is increased by 9.95% compared with CK.The content of sputum and humic acid increased,and compared with CK,the Cr content in Junda was significantly reduced.Under the treatment of 300+10,the chromium content in Junda was the lowest,which was 82.32% lower than that of CK.The effect of earthworm dung in high content is better than the low content.The humic acid content increased and the Cr content in the samarium decreased significantly.(6)In Cr-contaminated soils,humic acid was significantly increased in Junda compared with CK.The increase was-0.38~0.83%.At 300+30,the yield of Junda was higher than the control by 0.83%.The increase in humic acid and the increase in CK production.However,when the humic acid is 100+10 and 100+30,the yield of sputum is lower than that of CK. |
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