Nitrogen Footprint of a Recycling System Integrated with Cropland and Livestock in the North China Plain.

Nitrogen-based pollution from agriculture has global environmental consequences. Excessive use of chemical nitrogen fertilizer, incorrect manure management and rural waste treatment are key contributors. Circular agriculture combining cropland and livestock is an efficient channel to reduce the use of chemical nitrogen fertilizers, promote the recycling of livestock manure, and reduce the global N surplus. The internal circulation of organic nitrogen resources in the cropland-livestock system can not only reduce the dependence on external synthetic nitrogen, but also reduce the environmental impacts of organic waste disposal. Therefore, this study tried to clarify the reactive nitrogen emissions of the crop-swine integrated system compared to the separated system from a life cycle perspective, and analyze the reasons for the differences in nitrogen footprints of the two systems. The results showed that the integrated crop production and swine production increased the grain yield by 14.38% than that of the separated system. The nitrogen footprints of crop production and swine production from the integrated system were 12.02% (per unit area) and 19.78% lower than that from the separated system, respectively. The total nitrogen footprint of the integrated system showed a reduction of 17.06%. The reduction was from simpler waste manure management and less agricultural inputs for both chemical fertilizer and raw material for forage processing. In conclusion, as a link between crop planting and pig breeding, the integrated system not only reduces the input of chemical fertilizers, but also promotes the utilization of manure, increases crop yield, and decreases environmental pollution. Integrated cropland and livestock is a promising model for agriculture green and sustainable development in China.

High quality draft genomic sequence of Flavobacterium enshiense DK69(T) and comparison among Flavobacterium genomes.

Flavobacterium enshiense DK69(T) is a Gram-negative, aerobic, rod-shaped, non-motile and non-flagellated bacterium that belongs to the family Flavobacteriaceae in the phylum Bacteroidetes. The high quality draft genome of strain DK69(T) was obtained and has a 3,375,260 bp genome size with a G + C content of 37.7 mol % and 2848 protein coding genes. In addition, we sequenced five more genomes of Flavobacterium type strains and performed a comparative genomic analysis among 12 Flavobacterium genomes. The results show some specific genes within the fish pathogenic Flavobacterium strains which provide information for further analysis the pathogenicity.