Xu Hong-Wei, Li Na, Feng Yong-Zhong, Ren Guang-Xin, Xie Cheng-Hui, LÜ Hong-Fei, Ma Xing-Xia, Hao Jia-Qi
College of Agronomy, Northwest A&F University, Yangling 712100, China.
Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100, China.
Huan Jing Ke Xue. 2020 Dec 8;41(12):5668-5676. doi: 10.13227/j.hjkx.202005151.
In order to explore the impacts of nitrogen fertilizer and straw returning methods on NO emissions, a two-factor split-zone design was adopted for experimentation under the winter wheat-summer maize rotation model in the Guanzhong area of Shanxi, China. The main areas of interest were conventional nitrogen (G) and reduced nitrogen (70% G); the sub-areas were straw no return (N), straw return (S), and straw return + biochar (SB); we analyzed their impacts on NO emissions and crop yield, and the relationships with related impact factors. The results showed that the NO emissions peaks appeared in the wheat season and maize season treatments within 5-16 days after fertilization, and also appeared after rainfall. The NO flux was significantly and positively correlated with soil temperature and NH-N content. Regardless of the wheat season, maize season, or annual total NO emissions, the 70% GSB treatment was the lowest and the GS treatment was the highest. At the same level of nitrogen application, S treatment increased NO emissions, SB treatment could reduce NO emissions, both S and SB treatments could significantly increase crop yields, and SB production increased more; 70%G-level annual NO emissions, when compared with the G level, had been reduced by 40% to 48%, while the yield has not decreased significantly. Through comprehensive consideration, a reduction of nitrogen by 30% was achieved through the combination of straw + biochar on the basis of conventional nitrogen application, while ensuring high crop yields and the best NO emissions reduction.
为探究氮肥和秸秆还田方式对一氧化氮（NO）排放的影响，在中国山西关中地区冬小麦—夏玉米轮作模式下采用两因素裂区设计进行试验。主要因素为常规施氮（G）和减氮（70%G）；副因素为不秸秆还田（N）、秸秆还田（S）和秸秆还田+生物炭（SB）；分析它们对NO排放和作物产量的影响以及与相关影响因素的关系。结果表明，NO排放峰值出现在施肥后5-16天内的小麦季和玉米季处理中，降雨后也会出现。NO通量与土壤温度和铵态氮（NH-N）含量显著正相关。无论小麦季、玉米季还是年度总NO排放量，70%GSB处理最低，GS处理最高。在相同施氮水平下，S处理增加NO排放，SB处理可减少NO排放，S和SB处理均能显著提高作物产量，且SB处理增产更多；70%G水平的年度NO排放量与G水平相比降低了40%至48%，而产量未显著下降。综合考虑，在常规施氮基础上通过秸秆+生物炭组合实现了减氮30%，同时保证了作物高产和最佳的NO减排效果。
