不同灌溉方式冬小麦农田生态系统碳平衡研究

全球气候变暖趋势明显,陆地生态系统碳循环的研究成为目前的研究热点,而农田生态系统是陆地生态系统的重要组成部分,由于农田生态系统是受人类强烈调节与控制的复合系统,其碳循环受各类农作措施的影响极大。新疆地处干旱区,水分条件是农田碳循环的最重要限制因子。为此,分析不同灌溉方式对冬小麦（Triticum aestivuml）农田生态系统碳平衡的影响,从而提出有利于新疆冬小麦生产的固碳减排的灌溉方式。试验于2012—2013年在伊宁县科技示范园冬小麦试验田进行,选择伊农18冬小麦品种为供试材料,确定滴灌和漫灌为两个试验主因子并设置小区。试验自冬小麦返青开始至完全成熟结束,期间平均每7天采1次样,其中用典型样株法采集小麦植株,分根、茎、叶等不同器官单独烘干测定植株固碳量;用静态钠石灰吸收法测定冬小麦土壤呼吸;收集整理已发表国内外文献中的各类碳排放参数确定本研究中所需参数;采用王小彬的碳平衡计算方法分析不同灌溉方式农田生态系统碳平衡,据此对滴灌和漫灌两种灌溉方式的冬麦农田作物生物量固碳、土壤碳排放量和作物生产过程中物质投入的间接碳排放量,以及两种灌溉方式下冬麦农田生态系统净碳值进行分析。试验结果表明：滴灌条件下冬麦农田生态系统小麦的固碳量、土壤碳排放总量分别比漫灌小麦的高出15.38%和11.43%,冬小麦穗是差异形成的主要原因;而农业生产资料排碳总量比漫灌少排3.88%;但无论是滴灌还是漫灌,耗电碳排放量均占农业生产资料碳排放总量的59%以上,是农业生产资料碳排放的第一大来源。两种灌溉方式下冬小麦田生态系统的净碳值均呈现出固碳并存在显著差异（p〈0.01）,且滴灌冬麦农田生态系统净碳值比漫灌高25.39%。因此,新疆冬小麦生产中采用滴灌方式更有利于农田生态系统的固碳,

Effect of irrigation modes on carbon budget in winter wheat field

Research in terrestrial ecosystem carbon cycle is an emerging field of interest due to global warming. Crop field ecosystem, closely regulated and managed by human and in which carbon movement is strongly affected by field management, is one important component of terrestrial ecosystems. Water conditions in Xinjiang are the most important restriction to the local field ecosystem carbon cycle because of the extremely arid climate. This paper aimed to analyze and evaluate the effects of irrigation modes on carbon emissions during winter wheat production in Xinjiang. Experiments were carried out on during 2012-2013 in the Agricultural Park of Yinning county, north Xinjiang; Variety “Yidong18” of winter wheat was chosen as research subject treatments and drip irrigation （DI） and flood irrigation （FI） were designed for plot experiments.From after-reviving to fully maturing, field data sampling and processing were conducted every 7 days. Typical individuals of wheat were collected and separated as root, stalk, leaf, etc., which dried in the oven for measurement of dry biomass. The soda-lime method was applied for soil respiration and a popular carbon balancing method suggested by Wang Xiaobing was used for the estimation of field ecosystem carbon budget, of which parameters required were referred from publications. Data was analyzed for carbon fixed by plants, direct emission by soil respiration, indirect ones from agricultural means of production （AMP） and the net carbon emissions （NCE） under two treatments. The results showed that carbon storage by plants and soil emission under DI were 15.38% and 11.43% higher than that under FI, respectively, and the difference was in the amount of carbon fixed by ears of wheat, AMP emission under DI was 3.88% lower than that under FI, of which emissions produced during electricity production （EP） accounted for more than 59% in any case.NCE was positive with a significant difference （p〈0.01） under all treatments, and was 25.39% higher than that under F