麦秸不同部位生物降解速率差异

通过外源添加娄彻氏链霉菌(Streptomyces rochei),研究其对麦秸不同部位腐解速率的影响,模拟常温、淹水条件,进行为期27 d的腐解试验,测定麦秸叶片、叶鞘、穗轴、茎以及根在腐解过程中的干物质损失率、纤维素酶活力、放线菌数量、纤维组分及结晶度、总酚酸理化指标,并对其进行相关性分析。结果表明:娄彻氏链霉菌能在淹水环境下成为优势菌株;麦秸不同部位腐解速率为:叶片 >叶鞘 >穗轴 >根 >茎;干物质损失率与纤维素酶活、纤维素酶活与总酚酸呈极显著正相关(P<0.01),干物质损失率与总酚酸呈显著正相关(P<0.01);麦秸不同部位中穗轴、茎和根的腐解速率比较慢,且穗轴、茎和根占整株麦秸的比重比较大,根据这一结论,将有机物料腐熟剂接种到麦秸的茎和穗轴部位,可加快麦秸的腐解速率,为秸秆的资源利用及接种装置在收割机上固定位置的确定提供科学依据。

The Differences of Biodegradation Rates in the Different Parts of Wheat Straw

Decomposing experiment was carried out to study the decomposition rates of different parts of wheat straw by adding Streptomyces rochei with a period of 27 d under the room temperature and flooding conditions. Physical and chemical indexes such as the rate of dry mat-ter, the activity of cellulose enzyme, the number of experimental fungus, fiber composition and crystallinity, and total phenolic acid were mea-sured and analyzed in different parts of straw leaves, sheaths, cobs, stems and roots. Results indicated that Streptomyces rochei became the dominant strains under the flooded environment. Wheat straw decomposing speed of different parts were: leaves >sheaths >cobs >roots >stems. Loss rate of dry matter and cellulose enzyme activity, cellulose enzyme activity and total phenolic acids had significant positive correlation at 0.01 level. Meanwhile, loss rate of dry matter and total phenolic acids were also positively correlated. The decomposing rates of cobs, stems and roots were slower than others, and they were accounted for a relatively large proportion of the whole wheat straw. According to the con-clusion, using the inoculum favorable wheat straw decomposition, inoculants should be inoculated into the stems and cobs site to speed up the decomposing of straw. It also could provide the scientific basis for resource utilization and determine a fixed position on the harvester for vac-cination equipment.