[Characteristics of Easily Oxidized Soil Carbon Content and Carbon Pool Management Index in Typical Climate Zones in Eastern China].

Climate and land use are important factors affecting the soil carbon pool and organic carbon influx. To explore the characteristics of active organic carbon content and carbon pool management index in farmland soils in typical climate zones, two types of farm land （dry land and paddy fields） and adjacent forest soils in four climate zones （temperate, warm temperate, subtropical, and tropical） in eastern China spanning north to south were selected for study. The permanganate oxidizable carbon （POXC） content in each climate zone was analyzed, and the soil lability of carbon （）, soil lability index （LI）, carbon pool index （CPI）, and carbon pool management index （CMI） under each land use type were calculated.

[Response of Organic Carbon Mineralization to Nitrogen Addition in Micro-aerobic and Anaerobic Layers of Paddy Soil].

In field conditions, a micro-aerobic layer with 1 cm thickness exists on the surface layer of paddy soil owing to the diffusion of dissolved oxygen via flooding water. However, the particularity of carbon and nitrogen transformation in this specific soil layer is not clear. A typical subtropical paddy soil was collected and incubated withC-labelled rice straw for 100 days.

[Effects of Organic Materials on Phosphorus Fractions and -harboring Bacterial Community in Karst Soil].

Efficient utilization of organic materials based on the rich resources in the karst region can promote soil fertility. Microorganisms have a crucial influence on soil phosphorus availability. is considered to be the encoding phosphatase gene that can reflect the hydrolysis of organophosphorus compounds for the soil bacterial community.

Value of serum miR-922 and miR-506 expression levels in the diagnosis and prognostic assessment of childhood acute lymphoblastic leukemia.

Objectives: To study the value of serum miR-922 and miR-506 expression levels in the diagnosis and prognostic assessment of childhood acute lymphoblastic leukemia (ALL).

Methods: A total of 132 children with ALL (ALL group) and 80 healthy children (healthy control group) were prospectively selected in this study. Quantitative real-time polymerase chain reaction was used to measure the expression levels of serum miR-922 and miR-506 in both groups.

[Responses of Soil Organic Carbon Fractions to Land Use Types in Hilly Red Soil Regions, China].

Land use type exerts important influences on soil organic carbon (SOC) and its fractions, and determines the stability of the carbon pool. Taking woodland as a reference, the content of SOC and its labile fractions[dissolved organic carbon (DOC), microbial biomass carbon (MBC), and particulate organic carbon (POC)] and non-labile fractions[mineral-associated organic carbon (MAOC)] in upland and paddy surface soils in hilly red soil regions were determined to explore the responses of SOC fractions to land use type. The results showed that the contents of SOC, MBC, POC, and MAOC ranked highest in paddy compared with upland and woodland.

[Characteristics of soil nitrogen cycle and mechanisms underlying the increase in rice yield with partial substitution of mineral fertilizers with organic manure in a paddy ecosystem: A review].

Partial substitution of mineral fertilizers with organic manure is a key strategy for stable and increase crop yield accompanying with zero growth of mineral fertilizers. Based on recent stu-dies, we reviewed the effects of partial substitution of mineral fertilizers with organic manure on rice yield, nitrogen utilization efficiency, soil nitrogen fractions, and microbial nitrogen fixation, ammonification, nitrification, and denitrification in rice paddy ecosystems. We further compared the cha-racteristics of soil nitrogen cycle of mineral fertilizers alone and partial substitution of mineral fertili-zers with organic manure.

[Straw Returning Plus Nitrogen Fertilizer Affects the Soil Microbial Community and Organic Carbon Mineralization in Karst Farmland].

The use of straw returning plus nitrogen fertilizer on farmland is one of the important agronomic practices for adjusting soil organic carbon (SOC) transformations. To explore the mechanisms of straw and nitrogen fertilizer application on straw and SOC mineralization in long-term fertilized soils, an incubation experiment with the C isotope tracing technique was conducted, which involved three long-term fertilized models in typical karst soils (no fertilization, inorganic fertilization, and a combination of inorganic fertilization and straw). To study the mechanisms of C-labeled straw and SOC mineralization, four treatments were designed as follows:no straw and nitrogen (control), and straw combined with three levels of nitrogen fertilizer (0, 214.

[Microbial Carbon Source Metabolic Profile in Rice Rhizosphere and Non-rhizosphere Soils with Different Long-term Fertilization Management].

Rhizosphere and non-rhizosphere soil samples under different long-term fertilization treatments including control without fertilizer (CK), chemical fertilization alone (NPK), rice residues combined with NPK (NPKS), 30% manure plus 70% chemical fertilizers (LOM), and 60% manure plus 40% chemical fertilizers (HOM) were collected from a paddy field in a red soil hilly area in Ningxiang City, Hunan Province, China. The characteristics of microbial carbon utilization in the soils were studied. Results of O-HO tracer analysis showed that both soil microbial biomass carbon content (MBC) and microbial growth rate () were highest in the HOM treatment, whereas they were lowest in CK.

[Characteristics of amino sugar accumulation in rhizosphere and non rhizosphere soil of rice under different fertilization treatments].

Soil samples were collected from paddy ecosystem under five long-term fertilization treatments, including control without fertilizer (CK), chemical fertilization alone (NPK), rice residue combined with NPK (NPKS), 30% manure plus 70% chemical fertilizer (LOM), and 60% manure plus 40% chemical fertilizer (HOM) in Ningxiang City, Hunan Province. The cha-racteristics of amino sugars accumulation in the rhizosphere and non-rhizosphere soils at rice tillering stage were analyzed. Results showed that the contents of soil organic carbon, total amino sugars and three amino monosaccharides (muramic acid, glucosamine and galactosamine) with long-term application of organic materials (rice residue or manure) were significantly higher compared with CK and NPK.

[Structure Analysis of Arbuscular Mycorrhizal in Roots from Different Shrubs in Karst Regions].

To explore if there are species-preferential characteristics of arbuscular mycorrhizal (AM) and host plants in karst regions, 13 shrub plants (including leguminosae and non-leguminosae) were selected to study the AM community structure of root samples. The soil nutrients in rhizosphere soils significantly differ among shrubs; they are higher in leguminosae than in non-leguminosae. Cluster analysis shows that all 13 shrubs can be infected by AM.

[Various effects on the Abundance and Composition of Arbuscular Mycorrhizal Fungal Communities in Soils in Karst Shrub Ecosystems].

Slope position is a key factor used in the restoration of vegetation in degraded karst ecosystems, and arbuscular mycorrhizal fungi (AMF) play an important role in improving this plant growth. However, little information is available regarding the effects of slope position on arbuscular mycorrhizal fungi. To test whether these fungal communities are impacted by slope position, the abundance, and composition of soil, AMF communities along the slope position were analyzed through terminal restriction fragment length polymorphism (T-RFLP) and real-time fluorescence-based quantitative polymerase chain reaction (real-time PCR).

[Effects of Lithology on the Abundance and Composition of Soil Nitrogen-fixing Bacteria and Arbuscular Mycorrhizal Fungal Communities in Karst Shrub Ecosystem].

Lithology is a key factor when used to restore vegetation in karst degraded ecosystems, and arbuscular mycorrhizal (AM) fungi and nitrogen-fixing bacteria play an important role in improving plant growth. However, little information is available regarding the effects of lithology on these two groups of microorganisms. To test whether these microbial communities are impacted by lithology, the abundance and composition of soil AM fungal and nitrogen-fixing bacteria communities were determined through terminal restriction fragment length polymorphism (T-RFLP) and real-time fluorescence-based quantitative PCR (real-time PCR).

[Effects of Slope Position and Soil Horizon on Soil Microbial Biomass and Abundance in Karst Primary Forest of Southwest China].

To explore the effects of slope position and soil horizon on soil microbial biomass and abundance, chloroform fumigation extraction methods and real-time fluorescence-based quantitative PCR (Real-time PCR) were adopted to quantify the changes of soil microbial biomass C, N and abundance of bacteria and fungi, respectively. Soil samples were harvested from three horizons along profile, i. e.

[Effect of long-term fertilization on lignin accumulation in typical subtropical upland soil].

To investigate the effect of long-term fertilization on lignin accumulation and clarify its influencing factors in subtropical agricultural upland soils, alkaline CuO oxidation and gas chromatography was performed to quantify the amount of lignin and its monomers components (V, S and C). The soil samples were collected from the fertilization treatments of NPK and NPKS (NPK combined with straw) in Huanjiang County, Guangxi Province (limestone soil) and Taoyuan County, Hunan Province (red soil). The results showed that NPK had no significant effect on the lignin content (Sumvsc) of limestone soil, whereas the content in red soil significantly increased by (55 ± 1)%.

[Response of mineralization of dissolved organic carbon to soil moisture in paddy and upland soils in hilly red soil region].

Typical paddy and upland soils were collected from a hilly subtropical red-soil region. 14C-labeled dissolved organic carbon (14C-DOC) was extracted from the paddy and upland soils incorporated with 14C-labeled straw after a 30-day (d) incubation period under simulated field conditions. A 100-d incubation experiment (25 degrees C) with the addition of 14C-DOC to paddy and upland soils was conducted to monitor the dynamics of 14C-DOC mineralization under different soil moisture conditions [45%, 60%, 75%, 90%, and 105% of the field water holding capacity (WHC)].

[Basidiomycetous laccase gene diversity in two subtropical forest soils].

As one of the key enzymes involved in lignin decomposition of forest litter, laccase plays an important role in the carbon cycling in forest ecosystem. By using TA cloning and sequencing, a comparative study was conducted on the basidiomycetous laccase gene diversity in the O horizon (litter layer) and A horizon (surface soil layer, 0-20 cm) in two subtropical forests (a primeval evergreen deciduous broadleaved mixed forest and an artificial masson pine forest). For the same soil horizons, the basidiomycetous laccase gene diversity and richness were higher in the primeval forest than in the masson pine forest; for the same forest ecosystems, the basidiomycetous laccase gene diversity and richness in the primeval forest were slightly higher in O horizon than in A horizon, but those in the masson pine forest were apparently lower in O horizon than in A horizon.

Land reclamation and short-term cultivation change soil microbial communities and bacterial metabolic profiles.

Background: Soil microbes play an important role in many critical ecosystem processes, but little is known about the effects of land reclamation and short-term cultivation on microbial communities in red soil. In this study, soil microbial communities under five land use patterns-artificial pine forest (Fp), tussock and shrub (TS), shrubbery (Sh), sugarcane (Su) and maize and cassava rotation (Ma)-were characterised by DNA fingerprinting and metabolic profiling to reveal how land reclamation and cultivation affect the underlying diversity and function of soil microbial communities in southwestern China.

Results: Eight years of reclamation and cultivation significantly affected population size, composition and structure, bacterial metabolic profiles and diversity values (Shannon-Wiener index) of soil microbial communities.

[Responses of soil properties to ecosystem degradation in Karst region of northwest Guangxi, China].

Four typical ecosystems, i.e., maize-sweet potato rotational cultivated land (KMS), grazing grassland burned annually in winter (KGB), natural restoration land (KNR), and primary forest land (KPF), in Karst region of northwest Guangxi were selected to investigate the responses of soil nutrients (C, N and P), soil microbial biomass, and soil structure to the degradation of ecosystem.

[Soil bacterial community structure in primeval forest and degraded ecosystem in Karst region].

By using PCR-RFLP, this paper studied the 16S rDNA gene diversity and phylogenesis of soil bacteria in primeval forest and degraded ecosystem in Karst region of Northwest Guangxi. More genotypes and higher diversity index were observed in the soil of primeval forest than in that of degraded ecosystem, and only two common genotypes were observed in the two soils. A clone from each genotype was randomly selected as representative for sequencing.