State Key Laboratory of Crop Biology and College of Agronomy, Shandong Agricultural University, Taian, Shandong 271018, PR China.
State Key Laboratory of Crop Biology and College of Agronomy, Shandong Agricultural University, Taian, Shandong 271018, PR China.
Sci Total Environ. 2019 Oct 15;687:1138-1146. doi: 10.1016/j.scitotenv.2019.06.146. Epub 2019 Jun 10.
The North China Plain (NCP) is typically cropped using a winter wheat-summer maize double cropping system, which has huge potential for straw production. The region also experiences atmospheric pollution caused by straw burning, which has become an important contributor to global warming. The goals of this experiment were to resolve the conflict between soil fertility and greenhouse gas emission when using straw return to the field and to identify the best balance between environmental protection and agricultural production. A randomized block design with three replicates was used. The design included three treatments based on the return of all winter wheat stalks to the field: (1) all summer maize stalks were pulverized mechanically and returned to the field (SR); (2) half of the summer maize stalks were pulverized mechanically and returned to the field (1/2 SR); and (3) all summer maize stalks were fully removed (control: CK). This long-term test was performed for 6 years. Straw returned to the field significantly increased greenhouse gas emissions. The cumulative CO emissions were higher by 32% under SR and by 17% under 1/2 SR compared with CK. The cumulative NO emissions were higher by 28% under SR and 15% under 1/2 SR compared with CK. The greenhouse gas efflux increased with increased amounts of straw returned to the field. Compared with SR, 1/2 SR significantly reduced greenhouse gas emissions, while still ensuring sustainable soil fertility. Additionally, our research showed that the upper part of the corn stalk is better for generating biomass energy than the lower part. This study provides a theoretical basis for using the upper stalk for bioenergy and the lower stalk for direct return to the field for fertilization.
华北平原通常采用冬小麦-夏玉米两熟制，秸秆产量巨大。该地区还受到秸秆燃烧引起的大气污染的影响，这已成为全球变暖的一个重要因素。本试验的目的是解决秸秆还田过程中土壤肥力和温室气体排放之间的冲突，并找到环境保护和农业生产之间的最佳平衡。采用三重复随机区组设计。设计包括三种处理，基于将所有冬小麦秸秆全部还田：（1）将所有夏玉米秸秆全部粉碎还田（SR）；（2）将一半的夏玉米秸秆全部粉碎还田（1/2 SR）；（3）将全部夏玉米秸秆移除（对照：CK）。这项长期试验进行了 6 年。秸秆还田显著增加了温室气体排放。与 CK 相比，SR 下的累积 CO 排放增加了 32%，1/2 SR 下的累积 CO 排放增加了 17%。SR 下的累积 NO 排放增加了 28%，1/2 SR 下的累积 NO 排放增加了 15%。温室气体通量随秸秆还田量的增加而增加。与 SR 相比，1/2 SR 显著减少了温室气体排放，同时仍能确保土壤肥力的可持续性。此外，我们的研究表明，玉米秸秆的上部比下部更适合产生生物质能。本研究为利用秸秆上部进行生物质能利用，下部直接还田施肥提供了理论依据。
