[Soil health evaluation of non-grain cultivated land: A case study of Dongwu Town, Ningbo City, Zhejiang Province, China].

Non-grain utilization of cultivated land threatens farmland ecological environment and soil health, which restricts grain production. To identify the key obstacle factors of cultivated soil under non-grain utilization, explore the changes of soil quality and function, and evaluate the effects of non-grain utilization on the health of farmland soil, we evaluated soil health of farmland under different non-grain utilization types (vegetables, bamboo-abandoned, nursery-grown plant-abandoned, nursery-grown plant-rice) by soil quality index and soil multifunctionality index method combined with sensitivity and resistance approaches. The results showed that soil organic carbon and total nitrogen (TN) in the bamboo-abandoned soil were 95.

[Effect of Long-term Straw Returning on the Mineralization and Priming Effect of Rice Root-carbon].

Long-term straw returning to the field changes the environmental conditions of rice paddy soil, which affects the mineralization and priming effect of residual rice roots in the soil, but the direction and intensity of its influence is not clear. Therefore, based on a long-term fertilization field experiment, C-CO isotopic labeling technology and laboratorial incubation were used to analyze the characteristics of mineralization of rice roots and native soil organic carbon, the intensity and direction of the priming effect, and the source partitioning of CO emissions in three treatments, consisting of no fertilization (CK), chemical fertilizer (CF), and straw returning with chemical fertilizer (CFS). The results showed that after 120 days of flooding incubation, the root residue (R) increased the cumulative CO emissions by 617.

[Characteristics of Paddy Soil Organic Carbon Mineralization and Influencing Factors Under Different Water Conditions and Microbial Biomass Levels].

Paddy soil often undergoes frequent dry-wet alternation. The change in water status not only affects the physical and chemical properties of the soil, but also changes the structure and diversity of the soil microbial communities, which in turn determines the rate of soil organic carbon mineralization. However, the effects of different water conditions and soil microbial biomass levels on the process of soil organic carbon mineralization and its mechanisms are still unclear.

[Effect of Water Management on Rice Growth and Rhizosphere Priming Effect in Paddy Soils].

The rhizosphere priming effect (RPE) caused by carbon inputs from crop rhizodeposits plays a key role in regulating the carbon emission flux and carbon balance of farmland soils. Due to frequent alternations between dry and wet conditions, CO and CH emissions and the RPE in paddy field ecosystems are significantly different to those of other ecosystems. Therefore, it is of great significance to determine the direction and intensity of the rice RPE under alternations of dry and wet to limit greenhouse gas emissions.

Metagenomic and C tracing evidence for autotrophic microbial CO fixation in paddy soils.

Autotrophic carbon dioxide (CO ) fixation by microbes is ubiquitous in the environment and potentially contributes to the soil organic carbon (SOC) pool. However, the multiple autotrophic pathways of microbial carbon assimilation and fixation in paddy soils remain poorly characterized. In this study, we combine metagenomic analysis with C-labelling to investigate all known autotrophic pathways and CO assimilation mechanisms in five typical paddy soils from southern China.

[Response of Extracellular Enzyme Activities to Substrate Availability in Paddy Soil with Long-term Fertilizer Management].

The availability of carbon (C), nitrogen (N), and other substrates in soil determines the growth and metabolism of microorganisms and affects the activity of extracellular enzymes. To study the activities of -1,4-glucosidase (BG) and -1,4--acetylglucosaminidase (NAG) in response to C and N availability, samples that underwent four treatments-non-fertilization (CK), chemical fertilizer (NPK), combination of organic manure and chemical fertilizer (OM), and mixture of straw and chemical fertilizer (ST)-were collected from long-term fertilization paddy soil and incubated for 0, 4, 8, and 12 months to obtain soil with different C and N availability gradients. The results showed that the dissolved organic carbon(DOC) content of OM and ST treatment samples was 2-3 times higher than that of CK and NPK treatment samples.

[Characterization of Soil Organic Carbon Mineralization Under Different Gradient Carbon Loading in Paddy Soil].

Available carbon is the most active part of the soil carbon pool. It is also the main carbon source of soil microbes and plays an important role in the processes of soil organic carbon mineralization and accumulation. However, the mechanisms are still not clear how soil organic carbon mineralization and its priming effect (PE) are affected by different input levels of readily available carbon, based on the growth requirements of microbes in paddy soil.

[Allocation and Stabilization Responses of Rice Photosynthetic Carbon in the Plant-Soil System to Phosphorus Application].

This research studied the response of the input and allocation of photosynthetic carbon (C) to phosphorus (P) in paddy soils. Two treatments were conducted in this experiment:no P application (P) and the application of 80 mg·kg of P (P). The rice cultivar was the indica Zhongzao 39.

[Effect of CO Doubling and Different Plant Growth Stages on Rice Carbon, Nitrogen, and Phosphorus and Their Stoichiometric Ratios].

The variation characteristics of ecological stoichiometric ratios can reflect the nature of plant adaptation to environmental changes. The C, N, and P contetns, and their stoichiometric ratios in different organs of rice were studied using a CO continuous labeling system, by simulating the increase of atmospheric CO concentration (800×10). The results showed that CO doubling promoted the growth of rice organs and increased the root/shoot ratio.

[Effects of Varying Long-term Fertilization on Organic Carbon Mineralization and Priming Effect of Paddy Soil].

A laboratory incubation experiment was conducted using the C isotope labeling technique to study the characteristics of organic carbon mineralization and their response to glucose addition when treated with a combination of straw and chemical fertilizer (ST), inorganic fertilizer (NPK), and non-fertilization (CK). The cumulative mineralization rate (ratio of accumulated mineralization amount to total organic carbon content) in CK reaches 1.64% at the end of incubation (56 days).

[Effect of Phosphorus Addition on the Abundance of Autotrophic CO-Fixation Microorganisms in Rhizospheric Soil from a Phosphorus-Limited Paddy Field].

A rice pot experiment was conducted to investigate the effect of phosphorus addition on the abundance of autotrophic CO-fixation microorganisms using phosphorus-limited paddy soil from the Changsha Observation and Research Station for the Agricultural Environment. Rice seedlings were transplanted in the paddy soil with or without phosphorus addition, corresponding to P-treated-pot (P) or control pot (CK), respectively. Rhizosphere soils were collected from the P and CK treatments during the tillering and shooting stages.

[Transformation and Distribution of Soil Organic Carbon and the Microbial Characteristics in Response to Different Exogenous Carbon Input Levels in Paddy Soil].

The turnover of soil organic carbon (SOC) and the activity of soil microbes can be influenced by exogenous carbon. However, microbial response characteristics of the transformation and distribution of available organic carbon under different levels remain unclear in paddy soils. C-labeled glucose was used as a typical available exogenous carbon to simulate indoor culture experiments added at different levels of soil microbial biomass carbon (MBC) (0×MBC, 0.

[Effects of Long-term Fertilization on Enzyme Activities in Profile of Paddy Soil Profiles].

The enzyme activity, which is closely related to soil material cycling (mineralization, transformation, etc.), can reflect soil quality and nutrient status. In order to explore the effect of long-term fertilization on the enzyme activity in paddy soil profile (0-40 cm), soils with organic fertilizer and inorganic fertilizer, and non-fertilized soils were selected, and the carbon and nitrogen contents, and the activities of -1,4-glucosidase (BG), and -1,4--acetylglucosaminidase (NAG) in 10cm depths of soil were analyzed.

[Dynamics of Rice Photosynthesized Carbon Input and Its Response to Nitrogen Fertilization at the Jointing Stage: C-CO Pulse-labeling].

Photosynthesized carbon (C) is an important source of soil organic C in paddy fields, and its input and distribution are affected by rice growth and soil fertility. Fertilizer application plays an important role in rice growth. The C pulse-labeling method was used to quantify the dynamics and distribution of input photosynthesized C in the rice-(rhizosphere-and bulk-) soil system and its response to nitrogen fertilizer (N) application.

[Responses of Extracellular Enzymes to Nitrogen Application in Rice of Various Ages with Rhizosphere and Bulk Soil].

Ecological enzyme activities are closely relevant to the carbon and nitrogen decomposition and mineralization of paddy soils, which can reflect the growth and metabolism of microorganisms. In order to clarify the response to nitrogen application by different enzymes in the rhizosphere and bulk soil of rice, the rhizosphere and bulk soil were identified using a rhizosphere bag. In addition, the -1,4-glucosidase (BG) enzyme; -1,4--acetylglucosaminidase (NAG) enzyme; and the effects of the rhizosphere, nitrogen application, and growth period on soil enzyme activities were analyzed.

[Allocation of rice photosynthates in plant-soil system in response to elevated CO and nitrogen fertilization].

To examine the allocation of rice photosynthates and its response to the elevated CO (800 μL·L) and N fertilization (100 mg·kg) at both tillering stage and booting stage in plant-soil system, rice was continually labelled with CO. The results showed that the rice root biomass at the tillering stage and the shoot biomass at the booting stage were significantly increased under elevated CO. Elevated CO increased the rice biomass and root-shoot ratio at tillering stage, but reduced it at booting stage.

[Responses of organic carbon mineralization and priming effect to phosphorus addition in paddy soils].

To understand the coupled controlling of carbon (C) and phosphorus (P) on the minera-lization of soil organic carbon and amended substrates in paddy soil, we investigated the effects of P addition on the decomposition of organic carbon and its induced priming effect by using C isotope probing technique in microcosm. The results showed that P addition accelerated the release of CO but inhibited the release of CH, leading to 53.1% reduction of total accumulated CH and 70.

Fe(II)/Cu(II) interaction on goethite stimulated by an iron-reducing bacteria Aeromonas Hydrophila HS01 under anaerobic conditions.

Copper is a trace element essential for living creatures, but copper content in soil should be controlled, as it is toxic. The physical-chemical-biological features of Cu in soil have a significant correlation with the Fe(II)/Cu(II) interaction in soil. Of significant interest to the current study is the effect of Fe(II)/Cu(II) interaction conducted on goethite under anaerobic conditions stimulated by HS01 (a dissimilatory iron reduction (DIR) microbial).

[Input and Distribution of Photosynthesized Carbon in Soil-Rice System Affected by Water Management and Nitrogen Fertilization].

Fertilizer and water management are two key factors for rice growth. A better understanding of the carbon (C) cycling in paddy soil requires investigation into the input characteristics and distribution dynamics of photosynthesized carbon in rice-soil system. We grew rice (Zhongzao 39) in PVC pots and used the C-CO continuous labeling method to quantify the allocation of photosynthesized carbon in rice-soil system under two regimes(Drying-rewetting .

[Effects of Soil Texture on Autotrophic CO Fixation Bacterial Communities and Their CO Assimilation Contents].

Autotrophic bacteria can assimilate atmospheric carbon dioxide (CO) and convert CO into organic carbon. The CO fixation by autotrophic bacteria is important for the improvement of carbon sequestration in agricultural soils. However, the effect of soil texture on autotrophic CO fixation bacteria and their CO fixation capacity is still unknown.

[Effects of Different Plantation Type on the Abundance and Diversity of Soil Microbes in Subtropical Red Soils].

Soil microbe plays an important role in carbon cycling, however, the effect of land use on soil microbe remain unclear. In present study, soil samples were collected from a long-term field experiment (Pantang Agroecosystem) in subtropical China (established in 1989), including paddy-rice (PR), upland-crop (UC), and paddy rice-upland crop rotation (PU) on soil bacterial (bacteria and Archaea) community structures. The effects of long-term different land uses were determined using terminal restriction fragment length polymorphism (T-RFLP) and quantitative PCR (RT-PCR) of the 16S rRNA gene.

catena-Poly[diaqua-tris(μ(3)-biphenyl-2,2-dicarboxyl-ato)disamarium(III)].

The title compound, [Sm(2)(C(14)H(8)O(4))(3)(H(2)O)(2)](n), is composed of one-dimensional chains and is isostructural with previously reported compounds [Wang et al. (2003 ▶). Eur.

Poly[[tetra-aqua-bis[μ(4)-2,2'-(p-phenyl-ene-di-oxy)diacetato][μ(2)-2,2'-(p-phenyl-ene-di-oxy)diacetato]dierbium(III)] hexa-hydrate].

The asymmetric unit of the title compound, [Er(2)(C(10)H(8)O(6))(3)(H(2)O)(4)]·6H(2)O, comprises one Er(3+) ion, one and a half 2,2'-(p-phenyl-enedi-oxy)diacetate (hqda) ligands, two coordinated water mol-ecules and three uncoordinated water mol-ecules. The Er(3+) ion is nine-coordinated by seven O atoms from hqda ligands and two O atoms from water mol-ecules. In the title compound, there are two types of crystallographically independent ligands: one with an inversion center in the middle of the ligand is chelating on both ends of the ligand towards each one Er center; the other hqda ligands are bridging-chelating on one side, and bridging on the other end of the ligand.