Graduate Thesis Or Dissertation
 

Effects of tillage systems on nitrate-nitrogen accumulation and soil structure

Público Deposited

Conteúdo disponível para baixar

Baixar PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/s1784q142

Descriptions

Attribute NameValues
Creator
Abstract
  • Effects of different tillage systems on nitrate-nitrogen accumulation in a 120 cm profile and on soil structure in the top 30 cm of the profile were studied under a fallow-wheat rotation. Treatment effects on nitrate-nitrogen, soil moisture and soil aggregation were measured. Fallow tillage treatments consisting of bare fallow, stubble-mulch and no-till were established on the trial plots. Bare fallow, stubble-mulch, and no-till tillage treatments had no significant effect on nitrate-nitrogen accumulation. However, the fact that nitrate-nitrogen accumulated at the end of fallow was several times higher than in the beginning of the fallow has great importance in terms of fertilizer application. Adequate moisture and temperature favored nitrate-nitrogen accumulation in the tillage plots during the fallow. The 0-10 cm soil layer appeared to be the accumulation zone in the three tillage systems. Effects of tillage treatments on soil structure were investigated through evaluation of aggregate size distribution and water stability. In the 0-10 cm soil layer, the aggregates larger than 0.84 mm, considered to be a good indicator of soil resistance to wind erosion, were more prevalent in bare fallow than in the other two treatments. The percentage of aggregates in the 2-4.75 mm range showed similar distribution patterns among the treatments. The 0-10 cm soil layer is disturbed every other fallow cycle in the bare fallow and every fallow cycle in the stubble-mulch. In notill, the 0-10 cm soil layer is disturbed only at planting. As a result, more destructive action of no-till and stubble-mulch may be reason for these differences. It should be noted that in no-till the soil is pulverized enough during seeding to favor low aggregation and stability.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Declaração de direitos
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using ScandAll PRO 1.8.1 on a Fi-6770A in PDF format. CVista PdfCompressor 5.0 was used for pdf compression and textual OCR.
Replaces

Relações

Parents:

This work has no parents.

Em Collection:

Itens

Miniatura Título Data de carga Acesso Ações
file details AvcinAbdulkadir1989.pdf 2017-08-22 Público Baixar