Study On Activities Of Soil Enzyme In Northeast Area Vegetable Greenhouse Induced By Pentachloronitrobenzene (PCNB)

PCNB is a kind of highly level effective, broad spectrum and powerful bacteriocide. Theresidual term is long. It is toxic and dose serious harmer to environment. Now it has beenlisted as priority control pollutant. There are many studys on PCNB, but it has not beenreported that influence of PCNB on soil enzyme in vegetable greenhouse. The pollutedsituation of PCNB is not clear in vegetable greenhouse, so there is more practical significanceto study the influence of PCNB on soil enzyme, with the rapid development of vegetablegreenhouse in northeast area. In this article we investigated the influence of PCNB oninvertase, urease, phosphatase and catalase in four vegetable greenhouse where belongs tonortheast area. The activity of soil enzyme changed with the different PCNB concentrationsand soil conditions. The change regular is summarized and that will supply the scientificfoundation for reasonable using PCNB in northeast area. The study showed there are significant influences on invertase, urease, phosphatase, andCatalase by PCNB in No.1 soil, which is the most fertile, and without using pesticide.Pesticide has been used in No.2 soil and the content of TP is much higher. Invertase andurease is influenced much by PCNB. The content of OM, TN, TP in No.3 soil is lower thanothers, in which also has used pesticide. PCNB just does influence on invertase in No.2. Theclay content is the lowest in No.4 soil. Pesticide has been used in No.4soil, too. Invertase andurease is also influenced much by PCNB. So there are significant influences on by PCNB infour tested soils. PCNB inhibits invertase in No.1 soil, the stronger inhibition is observed atthe higher. For the other soils, under the PCNB concentration of 10μg/kg, invertase activityis stimulated first, then inhibited. While invertase activity is inhibited at higherconcentration(50,150μg/kg). It adheres to the regular that the higher concentration of PCNBis, the stronger inhibition is observed. On the condition of 10μg/g which is near to the usedconcentration in field, Inhibition is still significant until soils have been cultivated for 30 days.So invertase is advised to be the biotoxical index of PCNB in soils.