Analysis of culturable and unculturable microbial community in bensulfuron-methyl contaminated paddy soils

To investigate the influence of bensulfuron-methyl(BSM)on culturable microbial quantities and unculturable microbial community structures,conventional and molecular biological methods were employed in five BSM treated soils with three replications,respectively. The results obtained with traditional culture-dependent methods showed that a low-level of BSM had slight and transient effects on culturable microorganisms;nevertheless,high concentration of BSM resulted in a dramatic decrease in bacterial colony fo...

Effect of different machinery and rolling times on the microbial activity of reclamation soil in coal area

Mechanical construction will put influence on the biological characters of reclaimed soils,as well as the soil quality.In order to explore the changing rule of soil microbial quantity and respiratory capacity under different construction machineries and rolling times,and find the optimal processing conditions,an experiment was set up and a simulation experimental area was chosen,in which we simulated the main types of reclamation in coal mine area.After 2 years’natural aging,we collected surface soil samples(0-20 cm)that can be used for experimental analysis.The result shows that changing rules of soil biological factors are different with different construction machineries,and soil properties are closest to the normal soil when adopting the combination of“crawler dozer×5 compaction times”and“dump truck×3 compaction times”,which shows that the soil quality is better under this condition.

Effects of different C/N ratios on the maturity and microbial quantity of composting with sesame meal and rice straw biochar

The purpose of this paper was to study the effects of different C/N ratios on the maturity and microbial quantity of com-posting with sesame meal and rice straw biochar.Rice straw was calcined into biochar as raw materials composting with sesame meal for 30 days,referring to Chenfu Agricultural Book in Sōuthern Song Dynasty(1127-1279 A.D.).Sesame meal was used to adjust the C/N ratio of compost,and three treatments were designed in the experiment,which were C/N ratios of 15,20 and 30,respectively.The results showed that C/N ratio of 20 was beneficial for promoting the temperature rise,the removal of water,the degradation of organic carbon,and the decrease of microbial quantity.The C/N ratio of 20 was beneficial to the compost maturity(T value was 0.47,final GI was 99.67%).The results of Pearson correlation analysis showed that C/N ratio was positively correlated with moisture content,total organic carbon and negatively correlated with germination index,indicating that high C/N ratio was beneficial to water removal and total organic carbon degradation.Therefore,we suggest that the suitable C/N ratio of rice straw biochar and sesame meal is 20.At the same time,we have proved that the composting method in Southern Song Dynasty is feasible,which is of great significance to understand the development of composting in China.