Kinetics of nitrification in selected Iowa soils treated with Stay-N 2000

dc.contributor.advisor Randy Jay Killorn Rovita, Dwi
dc.contributor.department Agronomy 2018-08-25T00:28:50.000 2020-06-30T07:47:56Z 2020-06-30T07:47:56Z Sat Jan 01 00:00:00 UTC 2005 2005-01-01
dc.description.abstract <p>Nitrification rates were investigated in selected Iowa soils that differed in organic carbon contents, pH, and texture. This study was conducted to evaluate nitrification inhibition by reformulated nitrapyrin [2-chloro-6-(tricholoromethyl) pyridine] or Stay-N 2000 developed by Platte Chemical Co (Greeley, CO) applied to 10 g of surface soils representing Clarion, Nicollet, Canisteo, and Okoboji series treated with a solution containing 2 mg of N as ammonium sulfate (NH4) 2SO4. A nonlinear regression was used to determine nitrate accumulation. First order equations were used to calculate the maximum nitrification rate (Kmax), the duration of lag period (t '), the period of maximum nitrification (Deltat), and the termination period of maximum nitrification (t s). The course of nitrification varied among soils used. Stay-N 2000 appeared to be the better inhibitor to extend the period of maximum nitrification compared to nitrapyrin; and as good as nitrapyrin in reducing maximum nitrification rates in two soils studied. The effectiveness of a given rate of Stay-N 2000 enhanced in soils with high pH and organic C, such as in the Okoboji soil. At the rate of 12 mug a.i. g-1 soil Stay-N 2000 reduced the maximum nitrification rate an appreciable amount in the Okoboji soil. Nitrification rates in soils were also affected by the rates of N applied to these soils. The delaying effect of nitrification seemed to be associated with high concentration of NH4+-N. As one important factor in regulating nitrification is substrate availability, which is often limiting the growth of nitrifiers. The NO3--N accumulation increased with increasing temperature in all moisture levels applied in the study and reduced at the soil moisture level of -1 kPa. The highest maximum nitrification rate (Kmax) occurred at 30°C and at a moisture potential level of -10 kPa. All metals used in the study seemed to reduce Kmax in the Clarion and Okoboji soils. The overall process showed that the more the NO3--N accumulation, the higher the maximum rate of nitrification (Kmax) and the longer the delay period (t').</p>
dc.format.mimetype application/pdf
dc.identifier archive/
dc.identifier.articleid 2587
dc.identifier.contextkey 6095120
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath rtd/1588
dc.language.iso en
dc.source.bitstream archive/|||Fri Jan 14 20:47:51 UTC 2022
dc.subject.disciplines Agriculture
dc.subject.disciplines Soil Science
dc.subject.keywords Agronomy
dc.subject.keywords Soil science (Soil fertility)
dc.subject.keywords Soil fertility
dc.title Kinetics of nitrification in selected Iowa soils treated with Stay-N 2000
dc.type article
dc.type.genre dissertation
dspace.entity.type Publication
relation.isOrgUnitOfPublication fdd5c06c-bdbe-469c-a38e-51e664fece7a dissertation Doctor of Philosophy
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