基于土壤功能和粮食安全的后备耕地可能源化秸秆生态总量分析

Aggregation Evaluation on the Straw Resource for Energy Source in Reserve Cultivated Land by Considering Soil Function and Food Security

后备耕地土壤生态脆弱,秸秆还田具有维护土壤功能的作用。基于此,提出了土壤生态最小保留量的概念,并综合考虑粮食安全、作物单产、种植结构和草谷比,运用情景分析法评价了后备耕地可能源化秸秆的生态总量。研究发现:(1)受耕地后备资源影响,秸秆理论量较小。在高、中、低单产情景下,2050年理论秸秆总量分别为2658.69、1772.46和886.23万吨;(2)考虑土壤功能和粮食安全,高发展情景下2050年可能源化秸秆生态总量能够达到2066.40万吨,低情景仅10.70万吨;其中,新疆可能源化秸秆生态总量较大;(3)土壤生态最小保留量和区域作物单产,对可能源化秸秆生态总量影响较大;可构建农业生物质能开发生态补偿机制,进一步提高后备耕地农业生物质能生态潜力。

It has positive effect of straw incorporation on preventing the land from soil erosion. Therefore, the concept of Minimum Eco- logical Straw Returns Amount （MESRA） was put forward, and scenario analysis method was applied to design the MESRA. Then, a bottom up dynamic model was built, which considering per unit area yield, planting structure, straw-grain ratio and MESRA, and the model was used to evaluate the total amount of the straw that can be energy utilized. It finds that ： （1）Bounded by reserve cultivated land resources, the theoretical straw amount is small, respectively is 26. 5869 million ton, 17. 7246 million ton and 8. 8623 million ton in high, middle and low per unit area yield scenario in 2050. （2）When considering the MESRA and food security, the energy utilized strawamount will be 20. 664 million ton in high developing scenario, and 107 thousand ton in low developing scenario. Affected by the re- serve cultivated land resources, Xinjiang has the most straw resource in China mainland. （3）The MESRA and per unit area yield have obvious effect on the amount of energy utilized straw. But the total amount can be further improved by building up the provincial reserve cultivated land bio-energy development ecological compensation mechanism.