Herbicides effect on soil enzyme dynamics in direct-seeded rice
2016
Arya, S.R. | Ameena, M.
Summary: A field experiment was conducted to study the effect of new generation herbicides on soil enzymes, viz. dehydrogenase and urease for getting a better understanding of the possible response of soil microbial activities to low dose herbicides in dry sown rice. The treatments included different combinations of pre-emergent herbicides (bensulfuron-methyl + pretilachlor, pyrazosulfuron-ethyl) with post-emergent herbicide (azimsulfuron) and hand weeding along with a traditional herbicide oxyfluorfen. The effect of herbicides on soil enzyme dynamics showed that there was an increase in soil dehydrogenase enzyme activity (expressed in triphenylformazanhydrolysed/g of soil/24 hr) from 15 to 45 DAS after an initial decline. The activity of urease (expressed as urea hydrolysed per gram of soil per hr) as influenced by the herbicide treatments was not inhibited by any of the herbicide treatments. Hence it could be inferred that herbicides either used as pre-emergence or post-emergence remains in the active top soil and cause alternations in soil enzyme activities with respect to different days after treatments. The treated herbicides affected the soil enzyme activity but none of them registered highly negative effect on any of the soil enzyme activity in the present study under dry sowing.
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