Compost produced by straw and livestock and poultry manure under the action of micro-organisms is one of the main forms of organic alternative fertilizers at present. The present study explored the effects of compost substitution on soil greenhouse gas emissions, soil microbial community changes, and wheat yield to determine the best substitution ratio for reducing greenhouse gas emissions and soil microbial community changes and increasing wheat yield. Using the single-factor randomized block trial design, four treatments were employed, the characteristics of greenhouse gas emission, yield and yield components, and the changes of soil microbial community under different compost substitution ratio in the whole wheat growing season were determined by static box-gas chromatography. During the wheat season, both CO2 and N2O emissions were reduced, whereas CH4 emission was increased. That all treatments reduced the Global Warming Potential (GWP) and Greenhouse gas emission intensity (GHGI) in wheat season compared with T0. Compost substitution can alleviate the global warming potential to some extent. Under the condition of compost substitution, the wheat yield under T2 and T3 increased significantly compared with that under the control; however, the spike number and 1000-grain weight did not differ significantly among the treatments. When compost replacement was 30%, the yield was the highest. Under different ratios of compost substitution, the microbial communities mainly comprised Proteobacteria, Actinobacteria, Firmicutes, Patescibacteria, Chloroflexi, Acidobacteria, Bacteroidetes, Gemmatimonadetes, and Verrucomicrobia. The soil microbial community structure differed mainly due to the difference in the compost substitution ratio and was clustered into different groups. In conclusion, to achieve high wheat yield and low greenhouse gas emissions, compost replacement of 30% is the most reasonable means for soil improvement and fertilization.

No abstract

Characterizing the rhizosphere microbial community composition associated with enhanced crop yield and (or) greenhouse gases is an important first step towards understanding the role of the microbiota in rice paddies. This research aimed to decipher the influence of straw tea composting product combined with dicyandiamide amendment on greenhouse gas emission and microbial community in rice paddies.The results indicated that amendment of biological nitrification inhibitors can mitigate gas emissions and significantly increase rice yield by 41.70%, and improve the growth and development of the root system. Furthermore, composting product can mitigate greenhouse gas emissions, and bionitrification inhibitor combined with straw compost tea can effectively increase the growth and development of rice, the number of panicles, which are respectively 9.75% and 18.34%. However, the biological nitrification inhibitor impacted the communities of nitrogen-fixing bacteria (Proteobacteria), bacteria capable of eliminating nitrogen (Nitrospirae) as well as Verrucomicrobia known to be one of the most common and diverse phyla in soil habitats. As with bacteria, a distinct community structure and distribution patterns for archaea were observed in soils; however, the abundance, richness, regularity and diversity of archaea communities were significantly less in the different samples. In addition, biological nitrification inhibitors have had an impact in Euryarchaeota, responsible for the elimination of methane.

No abstract