开沟起垄穴直播方式对水稻分蘖前期甲烷排放的影响

Effects on methane emission in the precision rice hill-drop drilled field during the early tillering stage

【目的】研究开沟起垄式水稻精量穴直播技术对甲烷气体排放的影响.【方法】选取同步深施肥精量穴直播(30 cm)、宽窄行(35 cm+15 cm)精量穴直播和25cm固定行距精量穴直播3种直播方式,以人工撒直播、机插秧、手抛秧和人工移栽为对照,利用静态箱法测定水稻分蘖前期甲烷的排放通量.【结果和结论】对2010和2011年2年采集的数据分析结果显示,与非精量直播对照组相比,精量穴直播可以降低田间54.55%甲烷气体排放(P=0.011);不同栽种方式的甲烷平均排放通量顺序为:深施肥精量穴直播[(1.48±0.44)mg·m-2·h-1]<宽窄行精量穴直播[(1.65±0.30)mg·m-2·h-1]<固定行距精量穴直播[(2.57±0.56)mg·m-2·h-1]<人工撒直播[(2.89±0.61)mg·m-2·h-1]<机插秧[(3.77±0.64)mg·m-2·h-1]<人工移栽[(4.76±0.90)mg·m-2·h-1]<手抛秧[(5.33±0.84)mg·m-2·h-1].研究结果表明开沟起垄穴直播技术可以有效降低水稻分蘖前期甲烷气体的排放.

[Objective]To study the effects in the precision rice hill-drop drilled field on methane emission .[Method] Seven treatments were designed , including three precision rice hill-drop drilling types：the first precision rice hill-drop drilling with deep fertilization （30 cm） , the second with the alternate line （35 cm＋15 cm） and the third with fixed line （25 cm）,using mechanical transplanting , manual seedling broadcast-ing and manual transplanting as the control groups .Methane samples emitted from paddy field in 2010 and 2011 were collected using a closed-chamber technique .[Result and conclusion] The results showed that CH4 flux was reduced significantly in paddy fields treated by the precision rice hill -drop drilling compared with the non-precision rice field control within three weeks on the rice early tillering stage （ reduced by 54.55%, P=0.011）.Their flux order of CH4 emission were as follows, the first precision rice hill-drop drilling with deep fertilization type [（1.48 ±0.44） mg· m-2 · h-1 ] 〈the second with the alternate line [（1.65 ±0.30） mg· m-2· h-1] 〈the third with fixed line[（2.57 ±0.56） mg· m-2· h-1] 〈manual seedling broadcasting [ （ 2.89 ±0.61 ） mg · m -2 · h-1 ] 〈mechanical transplanting [ （ 3.77 ±0.64 ） mg· m-2 · h-1 ] 〈manual transplanting [ （ 4.76 ±0.90 ） mg · m-2 · h-1 ] 〈manual broadcasting [ （5.33 ±0.84 ） mg · m-2 · h-1 ] .The present study results showed that the precision rice hill-drop drilling technology can reduce the emission of CH 4 in the pre-tillering paddy field effectively .