Enzyme activities in soils as affected by management practices

dc.contributor.advisor M. Ali Tabatabai
dc.contributor.author Ekenler, Mine
dc.contributor.department Agronomy
dc.date 2018-08-25T02:51:26.000
dc.date.accessioned 2020-07-02T05:46:36Z
dc.date.available 2020-07-02T05:46:36Z
dc.date.copyright Tue Jan 01 00:00:00 UTC 2002
dc.date.issued 2002-01-01
dc.description.abstract <p>Studies were undertaken to investigate the long-term effects of lime application and tillage systems (no-till, ridge-till, and chisel plow) on soil microbial biomass C (Cmic) and N (Nmic) and the activities of glycosidases (alpha- and beta-glucosidases, alpha- and beta-galactosidases and beta-glucosaminidase); phosphatases (acid and alkaline phosphatases and phosphodiesterase); amidohydrolases (L-asparaginase, L-glutaminase, amidase, urease, and L-aspartase); and arylamidase at their optimal pH values. With the exception of acid phosphatase, which was significantly but negatively correlated, all other enzyme activities were significantly and positively correlated with soil pH values at four sites in Iowa. Delta activity/Delta pH values showed that among the enzymes studied beta-glucosidase, L-glutaminase, and acid phosphatase are the most sensitive to pH changes and could be used as tools for monitoring ecosystems health and function.;The effect of crop rotations and N fertilization on beta-glucosaminidase activity and its relationship to N mineralization were studied in soils of two long-term field experiments in Iowa. The activity of beta-glucosaminidase was significantly affected by crop rotations and N fertilization, and was significantly correlated with Corg and Norg, C mic, and Nmic in soils, and with cumulative N mineralized during 24 weeks of incubation at 30°C.;Studies to evaluate the effects of 23 trace elements on the activity of beta-glucosaminidase in three Iowa surface soils showed that at 5 mmol kg-1 soil, the activity of this enzyme was inhibited by 18, and activated by 5, of the trace elements tested, with Ag(I) and Hg(II) being the most effective inhibitors. Also, the activity of this enzyme was significantly affected by tillage systems (no-till, chisel plow, and moldboard plow) and four residue placements (bare, normal, mulch, and double mulch).;Other studies showed that the amounts of N mineralized in 56 surface soils, obtained from six states in the North Central region of the United States, by two biological and three chemical methods were significantly correlated with beta-glucosaminidase activity, and with organic C and total N. The amounts of N mineralized during 14 days of incubation of field-moist soils under waterlogged conditions at 30°C were the most significantly correlated with beta-glucosaminidase activity (r = 0.86***).</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/rtd/510/
dc.identifier.articleid 1509
dc.identifier.contextkey 6074953
dc.identifier.doi https://doi.org/10.31274/rtd-180813-14312
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath rtd/510
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/77808
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/rtd/510/r_3073445.pdf|||Sat Jan 15 00:43:57 UTC 2022
dc.subject.disciplines Agricultural Science
dc.subject.disciplines Agriculture
dc.subject.disciplines Agronomy and Crop Sciences
dc.subject.disciplines Biochemistry
dc.subject.keywords Agronomy
dc.subject.keywords Soil science (Soil microbiology and biochemistry)
dc.subject.keywords Soil microbiology and biochemistry
dc.title Enzyme activities in soils as affected by management practices
dc.type article
dc.type.genre dissertation
dspace.entity.type Publication
relation.isOrgUnitOfPublication fdd5c06c-bdbe-469c-a38e-51e664fece7a
thesis.degree.level dissertation
thesis.degree.name Doctor of Philosophy
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