The single and combined effects of sulfamethazine and cadmium on soil nitrification and ammonia-oxidizing microorganisms.

The coexistence of antibiotics and heavy metals in soil has attracted increasing attention due to their negative effects on microorganisms. However, how antibiotics and heavy metals affect functional microorganisms related to nitrogen cycle remains unclear. The goals of this work were to explore the individual and combined effects of sulfamethazine (SMT) and cadmium (Cd), selected as target pollutants in soil, on potential nitrification rates (PNR) and ammonia oxidizers (ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB)) structure and diversity by 56-day cultivation experiment.

Differential responses of canonical nitrifiers and comammox to long-term fertilization in an Alfisol of Northeast China.

The newly identified complete ammonia oxidizer (comammox) that converts ammonia directly into nitrate has redefined the long-held paradigm of two-step nitrification mediated by two distinct groups of nitrifiers. However, exploration of the niche differentiation of canonical nitrifiers and comammox and their ecological importance in agroecosystems is still limited. Here, we adopted quantitative PCR (qPCR) and Illumina MiSeq sequencing to investigate the effects of five long-term fertilization regimes in the variations of ammonia-oxidizing bacteria (AOB), ammonia-oxidizing archaea (AOA), nitrite-oxidizing bacteria (NOB), and comammox abundances and comammox community composition in two soil layers (0-20 cm, topsoil; 20-40 cm, subsoil) in an Alfisol in Northeast China.

Microbial nutrient limitations limit carbon sequestration but promote nitrogen and phosphorus cycling: A case study in an agroecosystem with long-term straw return.

Soil fertility can be increased by returning crop residues to fields due to the cooperative regulation of microbial metabolism of carbon (C) and nutrients. However, the dose-effect of straw on the soil C and nutrient retention and its underlying coupled microbial metabolic processes of C and nutrients remain poorly understood. Here, we conducted a comprehensive study on soil nutrients and stoichiometry, crop nutrient uptake and production, microbial metabolic characteristics and functional attributes using a long-term straw input field experiment.

Toxicological effects of single and joint sulfamethazine and cadmium stress in soil on pakchoi (Brassica chinensis L.).

The combined pollution of heavy metals and antibiotics in soil has attracted increasing attention due to their negative effects on plant growth. The aims of this study were to evaluate the phytotoxicity of single and combined sulfamethazine (SMT) and cadmium (Cd), selected as target pollutants in soil, on growth and physiological response of pakchoi (Brassica chinensis L.).

Experimental supporting data on seasonal dynamics of different soil nitrogen pools affected by long-term fertilization regimes.

The data presented in this article are related to the research paper entitled "Changes in N supply pathways under different long-term fertilization regimes in Northeast China" [1]. Seasonal dynamics of soil NH -N, NO -N, soil microbial biomass nitrogen (N) and fixed NH were provided on the basis of a 26-year long-term experiment, including six treatments: no fertilizer (CK), recycled manure (M), N and P fertilizers (NP), P and K fertilizers (PK), N, P and K fertilizers (NPK), and NPK fertilizers with recycled manure (NPKM). The presentation of potential N retention and supply through soil microbial biomass N and fixed NH pools at different growth stages is helpful for comparing the effects of different N pools on soil N transformation and assessing synchronies between crop N demand and soil N supply through different N pools.

Evaluation of Different Types and Amounts of Amendments on Soil Cd Immobilization and its Uptake to Wheat.

Using amendments is a cost-effective method to soil cadmium (Cd) remediation, whereas knowledge about how different amendments and rates affect remediation efficiency remains limited. This study aimed to evaluate the impacts of different types and amounts of amendments on soil Cd immobilization and its uptake by plants. Biochar (BC), zeolite (ZE), humic acid (HA), superphosphate (SP), lime (L), and sodium sulfide (SS) were applied at three rates (low, medium, and high) ranging from 0.

Combined influence of external nitrogen and soil contact on plant residue decomposition and indications from stable isotope signatures.

External nitrogen (N) supply has been testified to exert important impacts on plant residue decomposition. The influence of N may be interactive with soil contact in terrestrial ecosystems. However, the joint mechanisms of decomposition of plant residues driven by soil contact and N addition remain incomplete.

Spatial Heterogeneity of SOM Concentrations Associated with White-rot Versus Brown-rot Wood Decay.

White- and brown-rot fungal decay via distinct pathways imparts characteristic molecular imprints on decomposing wood. However, the effect that a specific wood-rotting type of fungus has on proximal soil organic matter (SOM) accumulation remains unexplored. We investigated the potential influence of white- and brown-rot fungi-decayed Abies nephrolepis logs on forest SOM stocks (i.

Priming effects on labile and stable soil organic carbon decomposition: Pulse dynamics over two years.

Soil organic carbon (SOC) is a major component in the global carbon cycle. Yet how input of plant litter may influence the loss of SOC through a phenomenon called priming effect remains highly uncertain. Most published results about the priming effect came from short-term investigations for a few weeks or at the most for a few months in duration.

Toxicity of sulfadiazine and copper and their interaction to wheat (Triticum aestivum L.) seedlings.

A pot experiment was carried out to investigate the single and combined effect of different concentrations of sulfadiazine (SDZ) (1 and 10mgkg) and copper (Cu) (20 and 200mgkg) stresses on growth, hydrogen peroxide (HO), malondialdehyde (MDA), antioxidant enzyme activities of wheat seedlings and their accumulation. High SDZ or Cu level significantly inhibited the growth of wheat seedlings, but the emergence rate was only inhibited by high SDZ level. The presence of Cu reduced the accumulation of SDZ, whereas the effect of SDZ on the accumulation of Cu depended on their concentrations.

The combined effect of sulfadiazine and copper on soil microbial activity and community structure.

Elevated concentrations of heavy metals and antibiotics often coexist in agricultural soils due to land application of large amounts of animal manure. The experiment was conducted to investigate the single and joint effects of different concentrations of sulfadiazine (SDZ) (10mgkg and 100mgkg) and copper (Cu) (20mgkg and 200mgkg) on soil microbial activity, i.e.

[Study on Leaching Characteristic of Heavy Metal in the Manure-Amended Soil Using ICP-MASS].

Based on an 11-year fertilizer field trial (located at the lower liaohe river plain), the effects of different organic manure application rates on the accumulations of heavy metals (Cu, Zn, Cd and Cr) in surface soil (0-20 cm), and the leaching characteristic and vertical migration pattern of heavy metal have been investigated in this rainfed agro-ecosystem using undisturbed soil columns. The result showed that the content of heavy metal in surface soil was elevated with the increase of manure application. The increasing magnitude was in the order of Cd>Cu>Zn>Cr.

[Study on Contents and Budgets of Cu, Zn and Cd in an Arable Soil Using AAS].

Based on a long-term experiment in Shenyang Experimental Station, the effect of manure application on the contents and budgets of Cu, Zn and Cd in the arable soil was studied. The experiment included four treatments: no mature addition (CK), mature addition 10 t · ha⁻¹ year⁻¹(M1), 25 t · ha⁻¹ year⁻¹ (M2), and 50 t · ha⁻¹ year⁻¹(M3). The result showed that Cu, Zn and Cd in soil were accumulated with manure application and prolongation of experiment, and the accumulative magnitude increased with increasing of manure application.

Interactive effects of sulfadiazine and Cu(II) on their sorption and desorption on two soils with different characteristics.

Antibiotics and heavy metals often coexist in soils due to land application of animal wastes and other sources of inputs. The aim of this study is to evaluate the interaction of Cu(II) and sulfadiazine (SDZ) regarding to their sorption and desorption on Brown soil (BS, luvisols) and Red soil (RS, Udic Ferrosols) using batch experiments. The presence of Cu(II) significantly enhanced sorption of SDZ on BS at pH>5.

Occurrence of (fluoro)quinolones and (fluoro)quinolone resistance in soil receiving swine manure for 11 years.

Because of the widespread use of antibiotics in animal breeding, the agricultural application of animal manure can lead to the introduction of antibiotics, antibiotic-resistant bacteria and antibiotic resistance genes to the soil and surrounding environment, which may pose a threat to public health. In this study, we investigated the status of (fluoro)quinolone (FQ) residues and FQ resistance levels in soil with and without receiving long-term swine manure. Six FQs (pipemidic acid, lomefloxacin, enrofloxacin, norfloxacin, ciprofloxacin, and ofloxacin) were only detected in manured soil, with individual concentrations ranging from below the detection limit to 27.

[Basic features and monitoring methodologies of atmospheric nitrogen deposition].

Atmospheric nitrogen (N) deposition, including dry and wet deposition, is an important inorganic and organic N source for ecosystems, and also a key link of the N biogeochemical cycle. Recently, considerable active nitrogen has been emitted into the atmosphere due to enhanced human activities. High N emission leads to high deposition which has caused a series of environment risks, and more attentions have been focused on this issue.

[Determination of concentrations and distributions of Mn and Zn in maize under different fertilization regime using ICP-AES].

A long-term field experiment and ICP-AES analysis were conducted to study concentration and content of micronutrients Mn and Zn in maize under different fertilization systems. The results were as follows: (1) Concentrations of Mn in maize under NPKM and NPK treatments were significantly higher than those in M and control treatments. The concentration of Zn in grain of maize was similar under different treatments.

[The recycling rate of trace element Fe and Zn in agro-ecosystem using ICP-AES].

Input of trace elements Fe and Zn in the lower reach of Liaohe Plain under different fertilization systems was studied by long-term field experiment and ICP-AES analysis. The results showed that Fe and Zn were mainly from organic manure in agro-ecosystem. The residual rate of organic manure through a feeding-composting cycle in the absence of bedding materials was 21.

[Effects of long-term fertilizations on microbial biomass C and N and bacterial community structure in an aquic brown soil].

Taking a long-term field experiment on an aquic brown soil in the Shenyang Ecological Station of Chinese Academy of Sciences as a platform, the methods of traditional chloroform fumigation and modern PCR-DGGE were adopted to study the effects of different fertilizations on the changes of soil microbial biomass and bacterial community structure. During the whole period of the experiment, there was a similar trend in the dynamic changes of soil microbial biomass C and N. Long-term application of organic manure increased the soil organic C and the soil microbial biomass C and N significantly, while long-term application of chemical fertilizers had significant negative effects on the soil pH and soil microbial biomass C and N.

[Nutrient concentration and storage in different organs of Eucalyptus under effects of nitrogen topdressing].

A field experiment was conducted to study the effects of nitrogen (N) topdressing on the biomass accumulation and nutrient concentration and storage in different organs of two-year-old eucalyptus. Comparing with the control, N topdressing increased the eucalyptus biomass by 24.2%.

[Study on the main influencing factors of black soil spectral characteristics].

To develop soil properties quick measuring methods, promote the development of quantitatively remote sensing studies relating to terrestrial ecosystem, and deepen the application of remote sensing in agriculture, the hyperspectral reflectance of black soil in Songnen Plain, northeast China, was analyzed with spectral analysis methods (continuum removal, spectral angle match and spectral feature fitting) and statistic methods to discover the reflectance spectral characteristics and its influencing factors. The results are as follows: the soil parent material determines the basic characteristics of reflectance of the black soil, which is the mixture of montmorillonite and illite, and consistent with mineral analysis result. Organic matter is the main factor determining the curve shape of black soil reflectance in the region shorter than 1 000 nm, and indirectly influencing the reflectance in the region longer than 1 000 nm because of the correlation with soil moisture and mechanical composition.

[Effects of land use type on soil organic carbon storage in aquic brown soil].

The profile distribution of soil organic carbon (SOC), its storage, and carbon/nitrogen (C/N) ratio at the depth of 0-100 cm under different land use types were investigated in this paper. The results showed that the profile distribution of SOC varied significantly with land use type. The SOC contents in each soil layer in forestland, mowing land and wasteland were all higher than that in agricultural land.

[Decomposition process and residual rate of organic materials C and N in soils].

By using nylon mesh bags and sand filter tubes, this paper studied the decomposition of organic materials in the soils at Shenyang and Hailun eco-experimental stations of CAS to investigate the dynamic changes of their organic C and N during decomposition. The results showed that the decomposition process could be divided into two phases, i.e.

[K fertility and K deficit index of aquic brown soil under different fertilization systems].

A 15-year fertilization experiment was conducted on an aquic brown soil to study the variations of its K fertility and the index of K deficit under different fertilization systems. The results indicated that no K application accelerated the depletion of soil K, representing a certain decrease of soil available and slow-release K. Applying K alone could not keep soil K in balance, still having a decrease of soil available and slow-release K.

[Research advances in water-fertilizer effect on dry land farmland].

Water and fertilizer are the keys in improving dry land productivity, and the main factors limiting the agricultural development in dry land regions. For our food security and agricultural sustainable development, it' s of significance to bring the effect of water and fertilizer on increasing yield into full play. This paper introduced the design principles of several commonly used methods in researching the effect of water and fertilizer, e.