Conventional Farmland Research Articles

Fungal community composition changes and reduced bacterial diversity drive improvements in the soil quality index during arable land restoration

Arable land is facing the growing challenge of land degradation due to intensive use and this is beginning to affect global food security. However, active and passive restoration can improve soil characteristics and reshape microbial communities. Despite the increasing focus on changes in microbial communities during restoration, the mechanisms underlying how microbes drive the soil quality index (SQI) in arable land restoration remain unclear. In this study, we selected conventional farmland (CF, heavily intensified) and two restoration strategies (AR, artificial restoration; NR, natural restoration), with the same context (including soil texture, climate, etc.), and measured the microbial indicators over 2 years to investigate the mechanisms driving SQI improvement on restored arable land. The AR and NR treatments resulted in a 50% and 58% increase in SQI, respectively, compared to CF as soil nutrient levels increased, resulting in higher microbial biomasses and enzyme activities. Microbial abundance on the AR land was approximately two times greater than on the NR land due to the introduction of legumes. Bacterial diversity declined, while fungi developed in a more diverse direction under the restoration strategies. The AR and NR areas were mainly enriched with rhizobium (Microvirga, Bradyrhizobium), which contribute to healthy plant growth. The pathogenic fungi (Gibberella, Fusarium, Volutella) were more abundant in the CF area and the plant pathogen guild was about five times higher in the restored areas. Following arable land restoration, microbial life history strategies shifted from r-to K-strategists due to the higher proportion of recalcitrant SOC (DOC/SOC decreased by 18%–30%). The altered microbial community in the restored areas created new levels of functionality, with a 2.6%–4.3% decrease in bacterial energy metabolism (oxidative phosphorylation, C fixation, and N metabolism decreased by 7%, 4%, and 6%, respectively). Structural equation modelling suggested that restoration strategy affected SQI either directly by increasing total soil nutrient levels or indirectly by altering the microbial community and that fungal community composition and bacterial diversity made the largest contributions to SQI. These results provided new insights into soil quality improvement from a microbial perspective and can help guide future arable land restoration.

Land-use pattern and landscape structure impact butterfly diversity and abundance in organic agroecosystems

ContextAgricultural intensification and land-use patterns impact biodiversity and reduce ecosystem functions. Organic farming is often seen as a more biodiversity friendly way of farming. However, not all organic farming is equally supportive for biodiversity, structural diversity of the farms has a great impact and the often high intertwinement of organic and conventional farmland causes spill-over problems.ObjectiveOn organic farmland in central Italy, we analysed butterfly diversity and community structures in different land-use categories across a heterogeneous landscape. We aim to analyse the impact of the different land-use structures such as hedges and forest edges on this farmland, as well as the influence of adjoining conventionally farmed areas.MethodsWe studied butterflies on organic farmland including olive and hazelnut plantations, as well as meadows and fallow land, surrounded by hedges and forests. Hereby we considered the effects of land-use on the studied site and the adjoining land, e.g., semi-natural habitats (as hedges or forest edges), organic or conventional farmland. We counted butterflies along line transects and recorded habitat parameters for each transect. All encountered butterflies were classified according their ecological demands, behaviour, and life-history.ResultsWe found highest mean butterfly species richness in fallow land and lowest in hazelnut plantations. Species community structures differed hardly between plantations and meadows, but considerably compared to fallow land. Butterfly abundances are reduced for olive plantations adjacent to agricultural fields treated with pesticides, compared to such surrounded by organic fields. Habitat para-meters such as the number of flowering plant species and shade impact butterfly diversity and abundance. Forest edges producing considerable shadow to the transects had a significantly negative effect on diversity and abundance, while the influence of hedges was positive.ConclusionsBased on our findings, we conclude that also organic farmland has different degrees of biodiversity depending on a variety of land-use pattern. In particular, habitat heterogeneity and a high diversity of flowers positively influence butterfly diversity. The intensive mixing of organic and conventional agriculture must be seen critical for conservation as negative effects might spill over to organic fields, but might be compensable by landscape structures like hedges.

Vertical farming for crop production

Vertical farming for crop production

A moderate differential effect of organic and conventional agriculture across taxonomic groups inhabiting farmland ponds

Abstract Organic agriculture is increasingly promoted as a more environmentally friendly alternative to conventional agriculture, as it restricts the use of fertilisers and synthetic pesticides. However, the impact of both farming systems on aquatic biodiversity is strongly debated. Ponds are abundant in agricultural landscapes and strongly contribute to biodiversity. They also respond strongly to land use on a very local scale. The present study assessed the effects of conventional and organic agriculture on the taxonomic diversity of multiple groups of aquatic organisms at local and regional spatial scales. We conducted a broad scale field survey to quantify the differential impact of conventional and organic agriculture on local environmental conditions in ponds, on community composition and on local, among site and regional diversity of macrophytes, cladoceran zooplankton and selected macroinvertebrates in Belgian farmland ponds (Flanders). We observed that organic agriculture was moderately positively associated with higher local species richness for shoreline vegetation, but not for other organism groups. Only minor differences were observed for among‐pond variation, and these were mostly related to rare species of cladocerans and heteropterans. At the regional scale, ponds in organic showed higher species richness than in conventional farmland for shoreline vegetation, emergent vegetation, and cladoceran zooplankton, but lower for coleopterans and gastropods. There was no significant effect of agricultural type on water quality. We conclude that organic farming is associated with moderate positive effects on pond biodiversity and regional species richness of plants and zooplankton. We observed no systematic differences between the two types of agriculture in local environmental conditions in ponds. The absence of large differences in biodiversity and water quality between ponds located in organic and conventional farmland might be related to the dominance of intensive conventional farming in our study region and the history of conventional farming around ponds that are now surrounded by organic farming. Future studies should include other factors such as the structure of the landscape and the role of natural elements such as buffer strips surrounding the ponds.

Toxicological Comparison of Pesticide Active Substances Approved for Conventional vs. Organic Agriculture in Europe.

There is much debate about whether the (mostly synthetic) pesticide active substances (AS) in conventional agriculture have different non-target effects than the natural AS in organic agriculture. We evaluated the official EU pesticide database to compare 256 AS that may only be used on conventional farmland with 134 AS that are permitted on organic farmland. As a benchmark, we used (i) the hazard classifications of the Globally Harmonized System (GHS), and (ii) the dietary and occupational health-based guidance values, which were established in the authorization procedure. Our comparison showed that 55% of the AS used only in conventional agriculture contained health or environmental hazard statements, but only 3% did of the AS authorized for organic agriculture. Warnings about possible harm to the unborn child, suspected carcinogenicity, or acute lethal effects were found in 16% of the AS used in conventional agriculture, but none were found in organic agriculture. Furthermore, the establishment of health-based guidance values for dietary and non-dietary exposures were relevant by the European authorities for 93% of conventional AS, but only for 7% of organic AS. We, therefore, encourage policies and strategies to reduce the use and risk of pesticides, and to strengthen organic farming in order to protect biodiversity and maintain food security.

Fluctuating insect diversity, abundance and biomass across agricultural landscapes

Habitat destruction and deterioration of habitat quality caused a severe decline of biodiversity, such as insect diversity. In this study, we analyze insect diversity and biomass across agro-environments. We collected flying insects with 20 malaise traps across a landscape mosaic consisting of organic (eight traps) and conventional (four traps) farmland, as well as across agricultural land that has been recently converted from conventional to organic farming (eight traps). Sampling was conducted over 2 years, in 2019 and 2020, with in total 340 sampling events. We measured the dry weight of the captured organisms and identified species diversity by analyzing Operational Taxonomic Units (OTUs) and Barcode Index Numbers (BINs) via metabarcoding. The results obtained show temporal dynamics. The number of OTUs were always higher than the number of BINs. OTUs and BINs were moderately to highly correlated, while the number of OTUs and BINs were only moderately positively correlated with dry biomass. OTUs and BINs as well as biomass were highest in the recently transformed farmland if compared with pure organic and conventional farmland sites, which showed no significant differences in respect of insect diversity. OTU and BIN numbers but not the OTU/BIN ratio significantly decreased with increasing distance from the nearest forest fringe. The numbers of OTUs, BINs and the OTU/BIN proportion, as well as OTU and BIN/biomass proportions varied strongly over seasons, irrespective of agricultural practice. Based on our findings, we suggest to combine data on insect species richness and biomass measured over a period of time, to derive a largely complete and meaningful assessment of biodiversity for a specific region.

Hazardous toxic metal(loid)s in top- and deep-soils during the transformation of aquaculture ponds restored to farmland

The pollution risks due to the soil migration of toxic metal(loid)s (TMs) are a greatly hazard to ecological environment as well as animal and human health. Previous studies have primarily focused on surface contamination while deep soil layers often contain dangerous levels of TMs. We used restored wheat and rice farmlands from aquaculture ponds as a case study to examine the ecological risk and distribution of TMs in soil profiles. The elements Cu, Zn, Cr, Cd, Hg and As were markedly enriched in the 60–180 cm soil layers of restored farmland, and their concentrations decreased in the several depths as follows: 120–180 cm > 60–120 cm > 0–60 cm. Concentrations of TMs were 9.5–128 % greater in the restored farmlands relative to farmlands not exposed to aquaculture practices. Cadmium and mercury were the most serious contaminants and increased the overall ecological risk. The subsoil of wheat farming system had the highest pollution risk versus the restored rice farmland at 60–120 cm due to elevated levels of Cu, Zn and Pb. Toxic metal(loid)s might be derived from natural sources in deep soil of conventional farmland whereas aquaculture practices were found to constitute the major contribution in the subsoil of restored farmland. Our results indicated that the TMs that were buried in deep soil layers migrated upward and were a significant pollution risk. Urgent actions should be taken to identify and alleviate the contamination sources of these deep soils in addition to the conventional leaching and migration processes of surface contaminants.

Accurate modeling of vertical leaf nitrogen distribution in summer maize using in situ leaf spectroscopy via CWT and PLS-based approaches

The vertical leaf nitrogen (N) distribution in summer maize is believed to be an important adaptive reaction to crop physiology and ecosystem functions. Therefore, it is of great significance to understand the vertical characteristics of leaf N concentration (LNC) across summer maize canopies for crop growth and production. However, the effect of vertical canopy position on LNC and subsequently leaf hyperspectral characteristics of the entire spectrum (350–2500 nm) for summer maize is poorly understood. The purpose of this work was to quantitatively study the effects of the N nutrition on vertical distribution of LNC, identify the sensitive layer and effective wavelength of leaves, and establish a in situ leaf spectrum monitoring model considering vertical distribution of LNC. Six N field trials were conducted for four consecutive years (2017–2020). In addition, the data of 30 farmers' conventional farmland management in 2020 were collected to check the robustness of the constructed optimal estimation model for LNC prediction. Leaf spectral measurements together with LNC were studied at three vertical leaf positions on the crop stem: upper, middle and lower. Spectral reflectance was processed by continuous wavelet transform (CWT); partial least square (PLS) was used to analyze the relationships between LNC of different layers and spectral reflectance. Field sampling indicated that LNC had a vertical distribution pattern and an evident decline from the upper to lower layer. CWT technique can significantly increase the prediction accuracy of LNC at different layers, and the best decomposition scale is CWT-1. The CWT-1-PLS model for predicting vertical LNC distribution had achieved relatively higher accuracy than that based on the full range of the raw hyperspectral reflectance (R), the LNC determination coefficient (R2val) of the validation dataset was 0.832, 0.857 and 0.811 for the upper, middle and lower layer, and the relative percentage deviations (RPDval) were 2.444, 2.432, and 2.181, respectively. Eventually, ten bands were selected as the effective wavelengths for predicting the vertical LNC distribution in the upper, middle and lower layer, respectively. Newly developed CWT-1-PLS model using the effective wavelengths for LNC prediction in different layers also performed well (RPDval>2.0) based on the field experiments validation. Moreover, the validation at the farmers’ fields also showed fine precision for upper (RPDval=2.012), middle (RPDval=2.137) and lower (RPDval=1.881) layer LNC prediction. These results are of great significance for the study of summer maize leaf reflectance modelling, especially for the studies of integrating hyperspectral measurements and leaf traits data.

Europe's Farm to Fork Strategy and Its Commitment to Biotechnology and Organic Farming: Conflicting or Complementary Goals?

The European Commission's Farm to Fork (F2F) strategy, under the European Green Deal, acknowledges that innovative techniques, including biotechnology, may play a role in increasing sustainability. At the same time, organic farming will be promoted, and at least 25% of the EU's agricultural land shall be under organic farming by 2030. How can both biotechnology and organic farming be developed and promoted simultaneously to contribute to achieving the Sustainable Development Goals (SDGs)? We illustrate that achieving the SDGs benefits from the inclusion of recent innovations in biotechnology in organic farming. This requires a change in the law. Otherwise, the planned increase of organic production in the F2F strategy may result in less sustainable, not more sustainable, food systems.

MULCH APPLICATION ON BARLEY GRAIN YIELD AND PHYSICOCHEMICAL PROPERTIES OF SOIL IN NEGELE ARSI DISTRICT, CENTRAL, ETHIOPIA

There is uncertainty about the type of mulch to use to reduce soil nutrient depletion and water loss and at the same time enhance crop yield that will also be influenced by the materials available locally for use and their management. The objective of this study was to investigate the effect of mulch application on barley grain yield and physicochemical properties of soil in Negele Arsi district, Central, Ethiopia. Experimental plots were laid on farmers fields’ in randomized complete block design by taking farmers field as a replication. Five farms of each with a currently mulched plot, a year ago mulched plot with perennial mulch and conventional fields as control (15plots of 10m in width and 20m in length in general) were selected for the establishment of the experiment. Subplots of 1mx1m at each corner and a center of each main plot were used for taking barley grain yield and soil data. A total of 30 soil samples collected from two depth layers: 0–20 and 20–40cm were air-dried and passed through a 2 mm sieve to remove roots, and large organic residues. Soil organic carbon concentration in the soil samples was determined by Walkley and Black method. The soil data were subjected to a two-way ANOVA analysis using the general linear model Procedures of SAS. The pairwise comparison method was also used to assess the mean difference of the treatment types and depth levels depending on soil properties. The average barley grain yield obtained from plots mulched with perennial mulch in 2018 (1.52±0.209kg) was higher than plots mulched in 2017 (1.48±0.135kg) and conventional farmland plots (1.44±.0962kg). The overall mean SOC stock was found to be higher under plots mulched in 2018(49.8291±17.9301) and lower in soils under conventional farm plots (39.1182±13.5183) than another treatment type. The highest overall mean of soil carbon stock under plots mulched in 2018 indicates that perennial mulch might be the remedy for replenishing the declining soil fertility on conventional farmlands and to increase barley grain yield on a sustainable basis. KEYWORDS: conventional farm, grain yield, perennial mulch, soil fertility

Farmland Rental Rates: Does Organic Certification Matter?

We estimate U.S. organic farmers’ marginal willingness to pay to rent an acre of certified organic land relative to conventional farmland. Using a selection-on-observables design and farm-level data on farmland rental rates, organic status, and many conditioning variables, we address the role of profitability in mediating the effect of organic status. We find a 26% rental rate premium for organic farmland not driven by higher profits on organic farms. This premium is a modest incentive for landowners but a barrier for tenants to convert to organic farming practices, which may explain limited growth in U.S. organic acreage.

Impact of conventional agriculture on the concentration and quality of water-extractable organic matter (WEOM) in the surface horizons of Retisols—A case study from the Carpathian Foothills in Poland

In spite of many studies focused on the impact of land use changes on soil organic carbon (SOC) and the total nitrogen (TN) and soil organic matter (SOM) budget, less is known about the fate of water-extractable organic matter (WEOM) after the conversion of forestland to conventional farmland. The main aims of this study were: 1) to determine the concentration of water-extractable organic carbon (WEOC) and water-extractable total nitrogen (WETN) in topsoil horizons of forestland soils and cropland soils in the Carpathian Foothills in southern Poland and 2) to determine the quality of WEOM in topsoil horizons of forestland soils and cropland soils. Soil samples from topsoil horizons of forestland soils (Oi and Ah horizons) and cropland soils (Ap horizons) were collected and the concentration of WEOC and WETN was determined. In addition, the quality of WEOM was determined using ultraviolet-visible (UV–vis) spectroscopy and Fourier-transform infrared attenuated total reflectance (FTIR-ATR) spectroscopy. The results of this comparative study clearly indicate that conventional agriculture significantly affects the concentration and quality of WEOM in surface soil horizons of Retisols in the Carpathian Foothills in southern Poland. Surface horizons of arable soils (Ap horizons) are characterized by a significantly lower mean concentration of WEOC and WETN in comparison with surface horizons of forestland soils (Oi and Ah horizons), and reflect changes in the content of bulk SOC and TN due to soil tillage. Mean concentrations of WEOC and WETN in the studied Ap horizons of arable soils are 1.98 mg l−1 and 0.15 mg l−1, respectively while the mean concentrations of WEOC and WETN in the Ah horizons of forestland soils are 15.53 mg l−1 and 0.84 mg l−1, respectively. The studied Oi horizons of forestland soils are characterized by the highest mean concentration of WEOC (44.53 mg l−1) and WETN (6.22 mg l−1). Mean specific UV absorbance values at wavelength of 254 nm (SUVA254) was the highest for WEOM from Ap horizons indicating the highest transformation of WEOM in these horizons. Mean FTIR-ATR absorption bands of WEOM obtained from Oi and Ah horizons are much more intensive than the bands of WEOM from Ap horizons, which is related to significantly lower concentration of WEOM in the latter horizons in comparison with Oi and Ah horizons of forestland soils.

IOT BASED AUTOMATIC RAIN WATER HARVESTING AND IRRIGATION SYSTEM

All living species in the world need is water. These days, water consumption in family units has expanded because of the ill-advised utilization of water in different exercises, for example, cultivating, vehicle washing or family unit cleaning. This causes water shortage and an expansion in family unit financial consumption.Today, farmers have a few issues in agriculture because of absence of downpours and shortage of water. The primary adage of this task is to spare time and exertion of each farmer by utilizing the water collecting strategy in a manual or programmed method of utilization. Manual intercession is required for conventional farmland procedures. Human intervention can be constrained with the motorized development of water frame-work. By utilizing soil dampness sensor levels of soil dampness/mugginess can be checked. At whatever point there is an adjustment in stickiness in the dirt this sensor detects the change and an intrude on signal is passed to the microcontroller and relying upon this the water system framework works. The mechanized water system framework gives a web interface to the client with the goal that the client can screen and control the framework remotely i.e., can make the water system framework ON and OFF remotely. The rainwater harvesting system can reduce the water shortage and useful in various situations.In view of measurable data accessible during quite a while, a reproduction framework is worked to decide the ideal precipitation assortment tank volume and assess the utilization of such a framework in specific areas. It creates and collaborates with the techniques for display-ing and mapping fields and water profitability of downpour took care of harvests in semiarid situations of India utilising hyper-spectral and multispectral remote detecting information and connecting the information to a similar field zone information and atmosphere station information. This is to give data to propel water reaping innovations in the horticultural grounds of the semi-dry situations of India.

Toward a standardized quantitative and qualitative insect monitoring scheme.

The number of insect species and insect abundances decreased severely during the past decades over major parts of Central Europe. Previous studies documented declines of species richness, abundances, shifts in species composition, and decreasing biomass of flying insects. In this study, we present a standardized approach to quantitatively and qualitatively assess insect diversity, biomass, and the abundance of taxa, in parallel. We applied two methods: Malaise traps, and automated and active light trapping. Sampling was conducted from April to October 2018 in southern Germany, at four sites representing conventional and organic farming. Bulk samples obtained from Malaise traps were further analyzed using DNA metabarcoding. Larger moths (Macroheterocera) collected with light trapping were further classified according to their degree of endangerment. Our methods provide valuable quantitative and qualitative data. Our results indicate more biomass and higher species richness, as well as twice the number of Red List lepidopterans in organic farmland than in conventional farmland. This combination of sampling methods with subsequent DNA metabarcoding and assignments of individuals according depending on ecological characteristics and the degree of endangerment allows to evaluate the status of landscapes and represents a suitable setup for large‐scale long‐term insect monitoring across Central Europe, and elsewhere.

Modified Farmland Fertility Optimization Algorithm for Optimal Design of a Grid-connected Hybrid Renewable Energy System with Fuel Cell Storage: Case Study of Ataka, Egypt

In this paper, a Modified Farmland Fertility Optimization algorithm (MFFA) has been presented for optimal sizing of a grid connected hybrid system including photovoltaic (PV), wind turbines and fuel cell (FC). The system is optimal designed for providing a clean, reliable and affordable energy by adopting hybrid power systems. This system is very important for countries looking to achieve their sustainable development goals. MFFA is proposed in order to reduce the processing implementation time. The optimization method depends on the high reliability of the hybrid power supply, small fluctuation in the injected energy to the grid and high utilization of the wind and solar complementary characteristics. Moreover, MFFA is applied to minimize the cost of energy while satisfying the operational constraints. A real case study of a hybrid power system for Ataka region in Egypt is introduced to evaluate the performance of the proposed optimization method. Moreover, a comprehensive comparison between the proposed MFFA optimization technique and the conventional Farmland Fertility Algorithm (FFA) has been presented to validate the proposed MFFA.

Varieties of agri-environmental schemes in China: A quantitative assessment

Agri-environmental schemes have become an effective policy measure to prompt farmers to protect rural farmland and landscapes. In recent years, 17 provincial governments including Sichuan, Jiangsu, Shanghai, Guangxi and Guangdong have shown increasing interest in promoting local experimentation with agri-environmental schemes. Based on two waves of farmer survey data in Eastern, Middle and Western China conducted in 2012 and 2015, this paper conducts a comparative study of three agricultural environmental policy models: the farmland protection fund model in Chengdu city (the Chengdu model), the farmland eco-compensation model in Suzhou city (the Suzhou model), and the conventional farmland protection model in Wuhan (the Wuhan model). Our quantitative analyses show that: agri-environmental schemes in China have significantly enhanced farmer enthusiasm toward farmland protection and lifted their policy satisfaction. Yet, the improvement in farmer knowledge of farmland ecological functions is limited; different agri-environmental models have diverse policy effects. Overall, the Chengdu model characterized by a combination of pension insurance and agricultural insurance benefits works better than the Suzhou model. Farmer participation in rural farmland and landscape protection is affected by multiple factors, among which education is the most significant.

The Mechanisms of High N2O Emissions from Greenhouse Vegetable Field Soils

Vegetable cultivation in China is characterized by high N application rate, multiple cropping, and frequent irrigation, which may have caused high N2O emission. However, the N2O emission characteristics and the underlying mechanisms responsible for N2O emission under high N application rate in the greenhouse vegetable field soils remains largely unknown. Thus, we conducted a field experiment to monitor N2O emissions using static chamber and gas chromatography techniques. Meanwhile, an incubation experiment was carried out to quantify soil gross N transformation rates and N2O emissions pathways via 15N tracing and N2O source partitioning methods, respectively. The experiment involved three treatments: Conventional farmland cultivated with soybean (CF), greenhouse vegetable field receiving only chemical N fertilizer (CGV), and greenhouse vegetable field receiving both organic manure and chemical N fertilizer (OGV). Our results showed that soil N2O emissions in the greenhouse vegetable fields, especially in OGV treatment, were significantly higher than those in CF treatment. Heterotrophic nitrification was the dominant pathway for N2O emissions accounting for up to 84.0% of the total N2O flux. The gross heterotrophic nitrification rate was 19.52 mg N kg−1 per day (accounting for 81% of the total nitrification rate) in OGV treatment, which was significantly higher than in CGV and CF treatment. As a consequence, the application of nitrification inhibitors might not be an effective mitigation options of N2O emissions from the greenhouse vegetable fields in China.

黑土母质熟化过程微生物群落碳源代谢特征

PDF HTML阅读 XML下载 导出引用 引用提醒 黑土母质熟化过程微生物群落碳源代谢特征 DOI: 10.5846/stxb201312313078 作者: 作者单位: 中国科学院东北地理与农业生态研究所,中国科学院东北地理与农业生态研究所,东北农业大学资源环境学院 作者简介: 通讯作者: 中图分类号: 基金项目: 公益性行业(农业)科研专项经费资助(201203030, 201303126);国家自然科学基金资助(41371296) Microbial metabolic characteristics of carbon in the black soil parent material maturation process Author: Affiliation: Northeast institute of Geogrophy and Agroecology, Chinese Academy of Sciences,Northeast institute of Geogrophy and Agroecology, Chinese Academy of Sciences, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:东北黑土区由于表土丧失,母质裸露等问题,严重威胁粮食生产和生态环境,通过揭示母质肥力形成过程中微生物群落的碳源利用特征可以让人们更好的理解肥力形成过程中相关微生物过程。以海伦农田生态系统国家野外科学观测研究站长期定位试验为材料,研究母质不同熟化过程下微生物群落碳源代谢特征,结果表明:苜蓿草熟化过程(PAfl)、农田化肥配施有机物熟化过程(PCS+F+OM)可培养微生物数量最多。自然熟化过程(PNat)、苜蓿草熟化过程、农田化肥农产品全循环熟化过程(PCS+F+BM)、农田化肥加有机肥配合型熟化过程可以将微生物活性提高到常规农田黑土的水平。不同熟化过程下微生物群落对单个碳源的利用不同。主成分分析表明自然熟化过程、农田化肥投入熟化过程(PCS+F)、农田化肥农产品全循环熟化过程、农田化肥加有机肥配合型熟化过程与常规农田黑土微生物代谢特征类似。研究表明不同母质熟化过程通过影响微生物群落结构导致对各个碳源的利用发生变化,最终改变了整体碳源代谢特征。 Abstract:The northeastern region of China represents the country's largest commodity grain base. The Mollisols present in this northeastern region are very suitable for farming. However, the loss of top layer Mollisols and exposure of parent material have severely threatened the ecological environment and national food security in northeastern China. The soil microbial biochemistry process is the engine required for the reconstruction for soil fertilizers. Thus, it is important to characterize the pattern of carbon utilization by soil microbial communities during the parent maturation process to understand how microbial processes contribute to soil fertility. This study focuses on the carbon utilization pattern of soil microbial communities under different long-term maturing treatments at the national observation station of the Hailun Agroecology System. The results showed that Parent-Alfalfa (PAlf), Parent Corn-Soybean+Fertilizer+Biomass cycle (PCS+F+BM), and Parent Corn-Soybean+Fertilizer+Oganic Matter (PCS+F+OM) treatments contained the highest number of microorganisms. Parent-Natural (PNat), PAlf, PCS+F+BM, and PCS+F+OM treatments increased microbial activity to the level recorded under conventional farmland treatment. Different maturing process treatments produced different carbon utilization patterns in the microbial community. In all treatments, the highest utilization rate of the carbon source was carbohydrate. Principal component analysis indicated that the microbial metabolic characteristics under PNat, Parent-No Fertilizer (PCS-F), PCS+F+BM, and PCS+F+OM processes were similar to that those under Stander Soil Corn-Soybean+Fertilizer (SCS+F) treatment. We conclude that the change in microbial community structure under different maturing processes caused variations in the carbon utilization pattern, which ultimately influenced the metabolism characteristics of the overall carbon sources. 参考文献 相似文献 引证文献

국내 유기상추의 생산환경 조사분석

Among pre-harvest environmental factors, increasing attention has been paid to the effects of chemical and microbiological factors on fresh produce. The occurrence and prevalence of these factors have been usually studied with regard to the final products at the post-harvesting stage and/or when they are sold in the market. However, the origin and routes of transmission of both factors remain to be clarified. In the present study, we examined the contamination levels of food-borne pathogens and chemical factors such as pesticide residues and heavy metals in 83 and 43 samples, respectively, including various soil, water, and fertilizer samples, as well as post-harvested and processed samples. Among the organic farming samples, only one pesticide, dimethomorph, was detected in the soil sample, however no pesticides were observed from any other samples in organic farming system. Thus, it was thought that might be contaminated from conventional farm land in the vicinity. Whereas many pesticide residues were detected in conventional farming systems such as soil, fertilizer, water, and fresh produce as expected. Furthermore, heavy metals detected from all tested samples did not shown contamination levels higher than the standard limit. We comparatively assessed the levels of contamination by food-borne pathogens on the samples from organic and conventional farming systems, and found aerobic bacteria at approximately 7 log CFU/g, with no significant differences observed between the two systems. Coliforms were present at lower levels than aerobic bacteria. No human pathogens were present among the coliforms detected, indicating that these bacteria are saprophytes without the ability to cause food-borne illnesses. In contrast, among the high-risk food-borne pathogens, only sporadic cells of Bacillus cereus were found on samples of organic farming system. These data extend previous findings that the most prevalent food-borne pathogen is B. cereus and demonstrate that it spreads to whole living plants via soil.

Importance of ecological compensation areas for small mammals in intensively farmed areas

Abstract Small mammals make up an important link in the food chain as many predator species feed on them. There are indications that small mammal populations in Europe are declining due to the intensification of agriculture. According to national legislation, farmers in Switzerland have to cultivate at least 7% of their land as ecological compensation areas and, thus, some alternative habitats that are possibly beneficial for small mammals have been created. In this study, we estimated the diversity and density of small mammals on two types of conventional farmland field types (artificial grassland and autumn-sown wheat) and three types of ecological compensation areas (wild-flower strips, herbaceous strips and low-intensity meadows) by use of capture-recapture in March, May and July 2003. The common vole Microtus arvalis was the most abundant and predominant species in all habitat types except in herbaceous strips, which harboured the highest diversity with six species caught. In March the density of sma...