Sugarcane/soybean intercropping with reduced nitrogen input improves crop productivity and reduces carbon footprint in China

Xiaolong Wang; Yuanjiao Feng; Lingling Yu; Yinghua Shu; Fengxiao Tan; Yonggang Gou; Shasha Luo; Wenting Yang; Zhixian Li; Jianwu Wang

doi:10.1016/j.scitotenv.2020.137517

Sugarcane/soybean intercropping with reduced nitrogen input improves crop productivity and reduces carbon footprint in China

Sci Total Environ. 2020 Jun 1:719:137517. doi: 10.1016/j.scitotenv.2020.137517. Epub 2020 Feb 22.

Authors

Xiaolong Wang¹, Yuanjiao Feng², Lingling Yu³, Yinghua Shu⁴, Fengxiao Tan⁵, Yonggang Gou⁶, Shasha Luo⁶, Wenting Yang⁶, Zhixian Li⁶, Jianwu Wang⁷

Affiliations

¹ College of Agriculture, South China Agricultural University, Guangzhou 510642, China. Electronic address: wangxiaolong@scau.edu.cn.
² Key Laboratory of Agro-Environments in Tropics, Ministry of Agriculture and Rural Affairs, South China Agriculture University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Eco-Circular Agriculture, South China Agriculture University, Guangzhou, 510642, China; College of Natural Resources and Environmental, South China Agricultural University, Guangzhou 510642, China. Electronic address: yjfeng@scau.edu.cn.
³ Key Laboratory of Agro-Environments in Tropics, Ministry of Agriculture and Rural Affairs, South China Agriculture University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Eco-Circular Agriculture, South China Agriculture University, Guangzhou, 510642, China; College of Natural Resources and Environmental, South China Agricultural University, Guangzhou 510642, China. Electronic address: lingling2013@scau.edu.cn.
⁴ Key Laboratory of Agro-Environments in Tropics, Ministry of Agriculture and Rural Affairs, South China Agriculture University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Eco-Circular Agriculture, South China Agriculture University, Guangzhou, 510642, China; College of Natural Resources and Environmental, South China Agricultural University, Guangzhou 510642, China. Electronic address: shuyinghua@scau.edu.cn.
⁵ Key Laboratory of Agro-Environments in Tropics, Ministry of Agriculture and Rural Affairs, South China Agriculture University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Eco-Circular Agriculture, South China Agriculture University, Guangzhou, 510642, China; College of Natural Resources and Environmental, South China Agricultural University, Guangzhou 510642, China. Electronic address: fxtan@scau.edu.cn.
⁶ Key Laboratory of Agro-Environments in Tropics, Ministry of Agriculture and Rural Affairs, South China Agriculture University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Eco-Circular Agriculture, South China Agriculture University, Guangzhou, 510642, China; College of Natural Resources and Environmental, South China Agricultural University, Guangzhou 510642, China.
⁷ Key Laboratory of Agro-Environments in Tropics, Ministry of Agriculture and Rural Affairs, South China Agriculture University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Eco-Circular Agriculture, South China Agriculture University, Guangzhou, 510642, China; College of Natural Resources and Environmental, South China Agricultural University, Guangzhou 510642, China. Electronic address: wangjw@scau.edu.cn.

PMID: 32120112
DOI: 10.1016/j.scitotenv.2020.137517

Abstract

Global climate change and decreases in available land are significant challenges that humans are currently facing. Alternative management approaches for sugarcane fields have great potential to help mitigate these problems in China. We hypothesized that soybean intercropping with reduced nitrogen input could increase crop productivity and reduce the carbon footprint (CF) of sugarcane fields in China. Therefore, a long-term field experiment from 2009 to 2017 in the Pearl River Delta of China was chosen to test this hypothesis. The results showed that the energy yields of sugarcane/soybean intercropping systems were 17.8%-39.4% higher than those of sugarcane monocropping systems. The energy yields of the same cropping systems using conventional and reduced N inputs (525 kg ha^-1 and 300 kg ha^-1) did not show a significant difference. Additionally, the CF values of the unit yield (CF_Y) for sugarcane/soybean intercropping were 3.2%-30.4% lower than those of the monocropping systems, showing the higher CF efficiency of the intercropping pattern, although the difference was not significant. The CF of the unit area (CF_A) and the CF_Y of all the cropping patterns at the conventional N level were 19.5%-62.0% higher than that at the reduced N level, demonstrating that reducing the nitrogen input could significantly lower the CF of the sugarcane fields. In addition, the high N level cased negative effects in terms of increasing the crop productivity and reducing the CF of the soybean/sugarcane intercropping pattern. In conclusion, sugarcane/soybean intercropping with reduced N input improved crop productivity while lowering the CF of sugarcane fields in China. The sugarcane/soybean (1:2) intercropping with 300 kg N ha^-1 system showed the best benefits in the Pearl River Delta of China. These advanced agricultural practices contributed to improved farmland use efficiency and clean production in an agricultural system.

Keywords: Carbon footprint; Crop productivity; Intercropping; Long-term field experiment; Nitrogen fertilizer; Sugarcane.

MeSH terms

Agriculture
Carbon Footprint
China
Fertilizers
Glycine max*
Nitrogen
Saccharum*

Substances

Fertilizers
Nitrogen