Ammonia volatilization from soils with surface rice straw residue /

(NH4)2SO4 VS- urea, and single vs. two equal split

Bibliographic Details
Main Author: Barghassa, Peyam, 1968-
Format: Thesis eBook
Language:English
Published: [Place of publication not identified] : [publisher not identified] ; 1995.
Subjects:
Online Access:Link to OAKTrust copy
Description
Summary:(NH4)2SO4 VS- urea, and single vs. two equal split
(NH4)2SO4 VS- urea, surface broadcast vs. deep placement of
activity. Subsurface application of N virtually eliminated
affected grain yield. A high urease activity (1 980 mg urea
alkaline Lake Charles clay (pH 7.4). The treatments in the
and field experiments were conducted to determine the effect
applications of the N. The presence of surface straw
applied N). The only variable to affect grain yield was the
Beaumont field study, but decreased it in the Lake Charles
environment for NH3 volatilization of surface-applied N,
following variables: surface rice straw vs. no straw,
greenhouse and lab consisted of all possible combinations of
greenhouse. No variable affected N uptake in the field,
in NH3 loss. Factors specific to each field may have
in the field consisted of all possible combinations of the
increased NH3 loss in all studies on both soils. Urea tended
kg-' (pH unit)-') of rice straw created a conducive
kg-' hr'), pH (7.2), and H-ion buffering capacity (73 mmol
N application method. Split-applied N increased yield in the
N, immediate flooding vs. delayed flooding. The treatments
NH3 1oss. Generally,a delayed flood increased NH3 loss-
NH4+ from deep-applied N before volatilization could occur.
of surface rice residue and related factors on NH3
other residue on the soil surface which may enhance NH,
particularly urea. Soil CEC's of over 50 cmol kg-' bound
possibly due to low NH3 losses in the field (O to 6% of
Reduced tillage rice production can result in rice straw and
study. Reduction in grain yield was not related to increase
Subsurface N application increased N uptake in the
the following variables: surface rice straw vs. no straw,
to volatilize more than (NH4)2SO4 due to greater straw urease
volatilization from an acid Beaumont clay (pH 5.4) and an
volatilization of surface-applied N. Laboratory, greenhouse,
Item Description:"Major subject: Soil Science".
Vita.
Physical Description:xv, 114 leaves : illustrations ; 28 cm.
Also available online.
Issued also on microfiche from Lange Micrographics.
Bibliography:Includes bibliographical references.