Eco-toxicological effect of fenvalerate on soil urease activity in subtropical orchards

Investigations to study the effects of 14 metallic cations on urease activity and nitrification rate in Hansi clay loam (Typic Ustochrepts) were undertaken at Haryana Agricultural University, Hissar, Haryana (India). The metallic cations inhibited soil urease activity, and the order of effectiveness varied when compared at 100, 500 and 1000 ppm. Increasing levels of metallic cations adversely affected the urease activity. Inhibitory effects of metallic cations at 1000 pprn decreased in order: Ag+ = Hg2+ > Cu2+ >Cd2+ > Co2+ >Ba2+ > Zn2+ > Ni2+ > Fe2+ > Cr3+ > Mn2+ > Sr2+ > Pb2+ > Al3+. Effects of Cr3+, Cu2+ and Hg2+ on nitrification were also tested. Above 80% of added N was nitrified at 21 days in the control (urea alone) and 100 ppm Cr3+ treatments, whereas addition of 500 and 1000 pprn cr2+ and 100, 500 and 1000 pprn Cu2+ delayed nitrification. A considerable amount of NH+4- remained unchanged in Hg2+ -treated soils after 28 days of incubation; these soils also contained more residual NO-2 than other treatments.

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EFFECTS OF CATECHOL AND P-BENZOQUINONE ON THE HYDROLYSIS OF UREA AND ENERGY BARRIERS OF UREASE ACTIVITY IN SOILS

Canadian Journal of Soil Science ◽

10.4141/cjss84-005 ◽

1984 ◽

Vol 64 (1) ◽

pp. 51-60 ◽

Cited By ~ 7

Author(s):

J. S. TOMAR ◽

A. F. MacKENZIE

Keyword(s):

Activation Energy ◽

Organic Matter ◽

Soil Organic Matter ◽

Key Words ◽

Urease Activity ◽

Urea Hydrolysis ◽

Urease Inhibitors ◽

Soil Urease ◽

Hydrolysis Of ◽

Hydrolysis Of Urea

The effects of the urease inhibitors, catechol and p-benzoquinone, and temperature on the hydrolysis of urea in five soils were investigated in a laboratory study. Urea hydrolysis decreased significantly with the amount of inhibitors applied and increased significantly with each 5 °C increase in temperature from 5 to 25 °C. The effectiveness of inhibitors generally decreased with increases in temperature from 5 to 25 °C. The correlation of hydrolysis of urea with organic matter contents of the soils was highly significant (r = 0.67** to 0.86**). Both catechol and p-benzoquinone tended to increase the energies and entropies of activation of soil urease and the effect was enhanced with a decrease in soil organic matter. It is suggested that an increase in the activation energy of the soil urease as a result of inhibitor use was related to an increase in the effectiveness of the inhibitor. Key words: Urease inhibitors, urea hydrolysis, energy of activation

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Relationships Between Soil Urease Activity and Other Soil Properties

Soil Science Society of America Journal ◽

10.2136/sssaj1977.03615995004100020036x ◽

1977 ◽

Vol 41 (2) ◽

pp. 350-352 ◽

Cited By ~ 63

Author(s):

M. I. Zantua ◽

L. C. Dumenil ◽

J. M. Bremner

Keyword(s):

Soil Properties ◽

Urease Activity ◽

Soil Urease

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Effect of Heavy Metals Cu, Cd, Pb and Zn on Enzyme Activity and Microbial Biomass Carbon in Brown Soil

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1073-1076.726 ◽

2014 ◽

Vol 1073-1076 ◽

pp. 726-730 ◽

Cited By ~ 6

Author(s):

Lei Yu ◽

Jie Min Cheng

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Enzyme Activity ◽

Microbial Biomass ◽

Catalase Activity ◽

Urease Activity ◽

Microbial Biomass Carbon ◽

Biomass Carbon ◽

Brown Soil ◽

Soil Urease

To get more sensitive index for making scientific and objective judgment on heavy metal pollution in brown soil, the influence which heavy metals Cu, Cd, Pb and Zn exert on soil urease, catalase activity and microbial biomass carbon content were evaluated by means of laboratory simulation.Experiment results showed that urease activity firstly increased with the addition of Cu, Cd and Pb, then showed decline trends. But for Zn, the activity of urease was obviously decline with the increased Zn concentrations. Catalase activity firstly increased with the addition of Cu then showed decline trend. But for Cd, Pb and Zn, the activity of catalase obviously declined. Microbial biological carbon all showed decline trends with the addition of Cu, Cd, Pb and Zn.

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