Effects Of Soil Contaminants From Cd And Zn On Soil Enzyme Activities And Plant Ryegrass Recovery

Heavy metal pollution in soil has become a very serious problem of environmental pollution.It has caused serious damage and impact on the environment and human health.The restoration of heavy metal pollution in soil has become an urgent problem for us to solve.Techniques and Methods for Exploring Heavy Metal Pollution in Soils In this paper,Cd and Zn are selected as research objects,and the following work has been done and certain research results have been obtained:(1)The effects of single pollution of Cd and Zn on seed germination and seedling growth of ryegrass were studied.The concentration gradient of Cd was set to 0,5,10,15 and 20 mg/kg,and the concentration gradient of Zn was set to 0,200,400,600,and 800 mg/kg.The results showed that: 1.Cd pollution was caused by single Cd contamination.The change of concentration had different effects on the germination potential,germination rate,seedling length and root breeding of ryegrass seeds.When the Cd pollution concentrations were 0,5,10,15 and 20 mg,the ryegrass seeds germinated.The potentials were: 90.35%,86.63%,45.26%,21.33%,and 9.82%;the germination rates of ryegrass seeds were: 90.35%,86.74%,65.33%,39.35%,and 21.76%;the seedling lengths were: 4.2 cm,6.3 cm,3.2 cm,1.4 cm,0.8 cm;the lengths of the seedling roots were: 3.5 cm,4.1 cm,1.9 cm,0.9 cm,and 0.6 cm,respectively.2.In the case of a single Zn pollution,the change of Zn pollution concentration also has different effects on the germination potential,germination rate,seedling length and root breeding of ryegrass seed,when the Cd pollution concentration is 0,200,400,600 respectively.At 800 mg/kg,the germination potentials of ryegrass seeds were: 92.33%,78.54%,65.33%,70.22%,66.67%;the germination rates of ryegrass seeds were: 94.11%,89.56%,87.67%,86.33%,85.33%;seedling length were: 7.2cm,9.1cm,7.1cm,6.9cm,6.8cm;the length of seedling roots were: 4.2cm,4.5m,4.3cm,4.4cm,4.2cm.(2)The effects of single and combined pollution of Cd and Zn on soil enzyme activities were discussed.Studies have shown that under a single Cd stress,when the concentration of Cd pollution is low,there is no significant effect on the enzyme activity of soil urease and catalase,and when the concentration of Cd pollution is high,the activities of these two enzymes are affected.Inhibition,sucrase has been inhibited by Cd pollution;Under a single Zn stress,low concentration of Zn has a certain activation effect on soil urease and sucrase,catalase is more sensitive to Zn,its activity has been Zn Inhibition of pollution;Compared to single Cd and Zn stress,the combined stress of Cd and Zn on soil urease and sucrase is less than the same level of single Cd and Zn stress,and catalase is the opposite.At the same time,through the analysis and comparison of the effects of Cd and Zn on the activity of the three enzymes,it was found that the range of soil urease activity was the greatest and could be used as an indicator to prevent or evaluate Cd and Zn contaminated soil.(3)The coupling effect of plant regulator DA-6 and the degradable chelating agent Gallic acid on the soil pollution of Cd and Zn by ryegrass was investigated.The results showed that when the DA-6 was not sprayed,the concentration of Gallic acid reached 2.5 mmol/kg.At the same time,the enrichment coefficients of ryegrass on Cd and Zn reached 2.62 and 2.15,respectively.After spraying DA-6,the enrichment coefficients reached 3.32 and 2.47,respectively,which was 26.7% higher than that when DA-6 was not added.14.9%.