Wang, F.-Y., Guangxi Crop Genetic Improvement and Biotechnology Lab, Guangxi Academy of Agricultural Sciences, 174 Daxue Road, Nanning, Guangxi  530007, China, Horticulture Institute, Guangxi Academy of Agricultural Sciences, 174 Daxue Road, Nanning, Guangxi  530007, China, Agricultural College, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi  530007, China; Li, C.-N., Guangxi Crop Genetic Improvement and Biotechnology Lab, Guangxi Academy of Agricultural Sciences, 174 Daxue Road, Nanning, Guangxi  530007, China, Guangxi Key Laboratory of Sugarcane Genetic Improvement/Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture/Sugarcane Research Institute of Guangxi Academy of Agricultural Sciences/Sugarcane Research Center of Chinese Academy of Agricultural Sciences, Nanning, Guangxi  530007, China; Wang, Z., Agricultural College, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi  530007, China; Lan, T.-J., Guangxi Crop Genetic Improvement and Biotechnology Lab, Guangxi Academy of Agricultural Sciences, 174 Daxue Road, Nanning, Guangxi  530007, China; Singh, R.K., Guangxi Crop Genetic Improvement and Biotechnology Lab, Guangxi Academy of Agricultural Sciences, 174 Daxue Road, Nanning, Guangxi  530007, China; Singh, P., Guangxi Crop Genetic Improvement and Biotechnology Lab, Guangxi Academy of Agricultural Sciences, 174 Daxue Road, Nanning, Guangxi  530007, China; Yang, L.-T., Agricultural College, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, Guangxi  530007, China; Li, Y.-R., Guangxi Crop Genetic Improvement and Biotechnology Lab, Guangxi Academy of Agricultural Sciences, 174 Daxue Road, Nanning, Guangxi  530007, China, Horticulture Institute, Guangxi Academy of Agricultural Sciences, 174 Daxue Road, Nanning, Guangxi  530007, China

The present study discussed the application of the intercropping system to improve land use efficacy and soil microbial activity. We assessed linkages of soil properties and unculturable diazotrophs community under three cultivation systems (monoculture sugarcane, peanut–sugarcane and soybean–sugarcane intercropping). Rhizosphere soil of sugarcane was sampled and DNA was extracted. We amplified the nifH gene and sequenced by high throughput sequencing. The bioinformatics analysis of sequenced data obtained a total of 436,458 nifH gene reads that are classified into 3201 unique operational taxonomic units (OTUs). A higher percentage of exclusive OTUs identified under soybean–sugarcane intercropping (< 375). The microbial structure results showed that Alpha-proteobacteria and Beta-proteobacteria were the dominant groups in all three cultivation systems. While genus such as Bradyrhizobium, Burkholderia, Pelomonas, and Sphingomonas was predominant in the intercropping systems and these diazotrophic bacterial communities were positively correlated to the soil pH and soil enzyme protease. Additionally, a lower quantity of available P in the soil of intercrops indicated a strong link between soil nutrients uptake and microbial activity. The results of the present study concluded some interesting facts of intercropping systems that positively improved the soil microbial activity and this kind of strategy could help to cultivate multiple crops to improve the economic growth of the country by sustainable sugarcane production. © 2019, Society for Sugar Research & Promotion.