Effect Of Lead On The Growth Of Celery And Alleviating Effect Of Potassium Dihydrogen Phosphate On Lead Poisoning

With the development of society and economy,heavy metal pollution of soil became an environmental problem that should be solved by researchers as soon as quickly.The harm to the soil and crops caused by heavy metals became more and more serious,thus more and more people paid attention to the heavy metal pollution.Because of the special properties of lead,it was widely used in industry.However,when lead entered the soil,it was hard to break down and remove.As a result,it not only hindered the crop growth and reduced their production,but also entered the body and was bad for people's health through the plant-soil system.As a kind of fertilizer,potassium dihydrogen phosphate had a significant effect on improving crop yields and quality,stable heavy metals in soil.This experiment studied plant height,dry weight,chlorophyll content,root activity of celery,enzyme activities of soil,and the alleviate effect of potassium dihydrogen phosphate on celery's lead poisoning,the results had been showed as follow:(1)With the increasing of the lead concentration in soil,plant height,biomass,chlorophyll content of celery increased at first and then decreased.When lead dosage was up to 500 mg/kg,the height,chlorophyll content and biomass of celery was the maximum when concentration of lead was 500 mg/kg.These indicators reduced when the concentration of lead was up to more than 500 mg/kg.Root activity of celery reduced when the soil had lead.(2)During the celery's growth stage,the activity of SOD,POD and CAT decreased as the propulsion growing.When the soil was added lead,with the increasing of lead's concentration,the activity of POD continued to increase.When the lead dosage 100?500 mg/kg,the activity of celery's SOD,CAT increased with the increasing of the amount of lead.When adding was more than 500 mg/kg,the activity of SOD and CAT decreased with the increasing of the concentration of lead.After the application of potash fertilizer in lead pollute soils,all kinds of enzyme activity had a trend to increase.(3)Different tissues of celery had different capability in accumulating Pb which was in the order of root>leaf>stem.It was further proved that Pb was mainly accumulated in roots of plants among the absorption of lead in different parts of celery and lead levels in soil were highly correlated.The correlation coefficients were 0.9273,0.9299 and 0.9105.Adding potassium dihydrogen phosphate to soil decreases available content of lead in soil.The effect of concentration of 400mg/kg was the best.The lead content of celery root,stem,leaf and available content of lead in the soil were of positively correlation,and the correlation coefficients were the 0.9414,0.9046 and 0.8916.(4)When application of potash fertilizer in lead pollutes soils,the activity of urease,alkaline phosphatase and invertase had a trend to increase while the activity of catalase had a trend to decrease with the addition of lead levels.Potassium dihydrogen phosphate could significantly affect the activity of enzyme in soil at the same lead level.With the increasing of potassium dihydrogen phosphate level,the activity of soil catalase and urease decreased,while alkaline phosphatase and invertase activity increased.