[Effects of Biogas Slurry Application on Soil Microbial Communities Structure and Function During Wheat-rice Stubble Period].

To reveal the effects of biogas slurry application on soil microbial community structure and function, a soil column experiment was constructed with three treatments[(no N addition, CM; conventional fertilization, SN; biogas slurry addition, SZ)]. The differences in composition, diversity, and structure of bacterial and fungal communities on day 1 and day 21 after soil flooding were evaluated, and their functions were predicted using Illumina high-throughput sequencing technology. The results of the analysis of α diversity showed that the fungal α-diversity indexes of CM, SN, and SZ treatments on day 1 were significantly higher than those on day 21, and there was no significant difference among the three treatments.

[Research progress of the response mechanism of wheat growth to waterlogging stress and the related regulating managements.].

The frequency of waterlogging events is increasing in recent years due to climate change. Wheat, a dryland crop, is particularly sensitive to waterlogging. Moreover, waterlogging stress is especially serious in the main wheat-producing regions at the middle and lower reaches of the Yangtze River as influenced by regional climate, soil, rotating system and other factors.

[Effects of nitrogen management on soil microbial community structure at different growth stages under straw returning in paddy soils].

Effects of different nitrogen application methods on microbial community structure of paddy soil at different rice growth stages were examined using phospholipid fatty acid analysis (PLFA) and Biolog technique. There were four treatments, no straw returning or fertilization (CK), straw returning +urea with the proportions of after wheat harvest, before rice transplanting, tillering stage and booting stage being 0:6:2:2 (T) and 3:3:2:2 (T), and straw returning+co-application of biogas slurry and urea with the proportion of after wheat harvest, before rice transplanting, tillering stage and booting stage being 3 (biogas slurry):3 (2biogas slurry+1urea):2 (urea):2 (urea)(T). Results showed that T significantly increased soil available nitrogen contents at all growth stages, which was significantly higher at maturity stage than that at tillering and booting stages.

[Assessment of Ecosystem Health of an Urban River Based on the Microbe Index of Biotic Integrity (M-IBI)].

The index of biotic integrity (IBI) has been widely used in river ecosystem health assessment. However, few studies have reported the application of microbial communities in ecosystem health assessment so far, especially for urban rivers. In this study, the Illumina high-throughput sequencing technique was applied to analyze the microbial community diversity and composition of five urban rivers selected in Zhejiang Province.

[Transformation and distribution of straw-derived carbon in soil and the effects on soil organic carbon pool: A review].

Farmland soil organic carbon (SOC) pool is a crucial component of global carbon cycle. Due to the widely-implemented straw returning, crop straws have become the primary exogenous carbon source for agricultural soils. The conversion and distribution of straw-derived carbon in soil directly affect the composition and contents of SOC, with further influence on soil nutrient cycling.

[Assessment of groundwater vulnerability to nitrate in He'nan Province of China based on principal component regression].

According to the hydrological and morphological characteristics, He'nan Province was divided into mountainous region and plain region. The level of rich water, infiltration modulus of precipitation, fertilization level per unit area, proportions of vegetable planting area, and soil texture were selected as the common indices, and the slope and groundwater depth were selected as specific indices to assess the groundwater vulnerability to nitrate. Principal component regression analysis was adopted to determine the index weights, and the spatial distribution of groundwater vulnerability to nitrate in He'nan Province was assessed with ArcGIS 9.