其他摘要 | In Loess Plateau of china, water and nitrogen are two key elements inhibit the
winter wheat production. Field experiments were conducted at the Changwu
Agricultural Research Station on the semiarid Loess Plateau of China during 2010 to
2012 for compared the different cultivation modes. The cultivation modes includes: (1)
cultivation mode1 Changwu134 treated with 150kg/ha -1 N, and 120kg/ha -1 P;
cultivation mode 2 Changhan58 treated with 120kg/ha -1 N and top-dressed 75kg/ha -1
N at heading, 120kg/ha -1 P; (3) cultivation mode 3 Changhan58 grown in plots with
wheat straw mulching during the summer fallow period and straw retention in
following sowing cycle plus a basal dose of 120kg/ha -1 N and top-dressed 75kg/ha -1 N
at heading, 120kg/ha -1 P, and ox manure at 4.5t/ha -1 and (1) cultivation mode 4
Changhan58 grown in plots subjected to plastic film mulching during summer fallow
period; the mulch was removed at sowing and 150kg/ha -1 N and 120kg/ha -1 P were
applied. Each treatment was replicated four times and arranged into a randomized
complete block design. Nitrogen (N) as urea and phosphorus (P) as SSP were used.
The inorganic fertilizer and ox manure were imposed prior to sowing. To compared
the influence of 4 different cultivation modes on two drought-resistance winter wheat
cultivars (Changhan58 and Changwu134) dry matter, water soluble carbohydrates,
total nitrogen accumulation and remobilization during grain filling periods; the yield
and yield components under different cultivation mode
The main conclusions of this study were as follow:
(1) Changhan58 cultivar accumulated more dry matter than that of Changwu134
cultivar. In Changhan58 cultivar, T3 ccumulated most dry matter. Among all parts of
the wheat internodes, the bottom-two-part accumulated more dry matter than that of
top-three-part. In bottom-two-part, lower internode (ERI) had the highest dry weight, in top-three-part; penultimate internode (PI) had the highest dry weight. Post-anthesis
synthesis dry matter had more contribution to final grain weight than that of
pre-anthesis accumulation dry matter. Compared with two consecutive growth period
(2010-2011 and 2011-2012), the more precipitation during late grain filling period in
2012, which inhibit the post-anthesis photosynthesis, less assimilates synthesis. So the
contribution of post-anthesis photosynthetic assimilate to grain weight is less than that
of in 2011 grain filling period. From apical to bottom, the value of CRAP is decrease.
The value of CAPA is increase.
(2) On average, Changhan58 cultivar accumulated more WSC in stem than that
of in Changwu134 cultivar. T3 can increase the WSC content in all wheat stem
segments. There is a significant positive relationship between WSC content on
anthesis and mobilization WSC (MWSC) (r=0.900 P=0.01 level), which illustrate the
importance of WSC content on anthesis. During grain filling period, there is an
asynchronized phenomenon in different internode segments showed their maximum
WSC content. The bottom-two-part showed their maximum WSC content on 15 day
after anthesis (daa), which earlier 5days than that of the top-three-part.
(3) With the development of grain filling, the total nitrogen (TN) concentration is
decrease in all vegetative organs. There is an exception organ for TN concentration
change during grain filling (For EXUI). Leaf organs had higher TN concentration than
that of in stem organs. In leaf organs, flag leaf (FL) had the highest value, in all
internode segments, EXUI had the highest value. Then, leaf organs the highest value
in nitrogen contribution (NC) to final grains, followed by glume + rachillae (GR), the
stem had lowest value in NC. 3 can increase the TN vertical distribution in winter
wheat. There is a significant positive relationship between TN concentration in
gradient1 (G1) and TN concentration in grain at maturity.
(4) T3 significant increased the LAI, flag leaf area and grain area. LAI and flag
leaf area can affect the photosynthesis, the stem surface area and grain area is
non-foliar organ. The higher value about them, the more photosynthate fixed by
photosynthesis (include leaf photosynthesis and non-foliar photosynthesis).
(5) The top grains had less starch, total nitrogen and volume accumulation than
that of middle and bottom grains. Changwu134 cultivar accumulated more dry matter
and starch in single grain than that of Chnaghan58 cultivar. It is concluded more
photosynthase mobilized from source organs is benefit to accelerate grain starch
accumulation in the early grain filling period. (6) Compared with different winter wheat cultivars Changwu134 and
Changhan58, the latter had high water use efficiency, harvest index and yield. T3 not
only increase the grain yield, but also promote the efficiency of water to produce the
grain particularly in the year which is have less precipitation.The increase of wheat
yield mainly attributed the increase of ear number and grain number per spike, while
was largely independent on grain weight.
Key words: Winter wheat (Triticum aestivum L.), Cultivation modes, Dry matter
mobilization, Total nitrogen mobilization, Grain yield, Water use efficiency |
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