Enhanced Food Quality: Effects of Composts on the Quality of Plant Foods

The effects of composts prepared from kitchen and yard wastes and farm yard manures were compared to mineral fertilizers on a range of quality parameters of cabbage, carrots, potato and tomato. Parameters evaluated were desirable versus undesirable nutrients in vegetables, storage quality as determined both by storage testing and enzyme assays and sensory quality. As a general trend, composts positively affected food quality, improved storage performance and yielded a somewhat superior sensory quality of tomatoes in particular. Composts significantly reduced nitrates and improved the nitrate to vitamin C ratio of vegetables. Vegetable yields for compost treatments were lower during the first two years but did not differ significantly after the third application.     

Status of Biological Control of Plant Diseases with Composts

? Composts have the potential to provide biological control of plant diseases. Foliar as well as root pathogens may be affected. Many factors control these effects. Heat exposure during composting kills or inactivates pathogens if the process is monitored properly. Unfortunately, most biocontrol agents also are killed by this heat treatment. Thus, biocontrol agents must recolonize composts after peak heating. The raw feedstock, the environment in which the compost is produced, as well as conditions during curing and utilization determine the potential for recolonization by this microflora and disease suppression. Controlled inoculation of compost with biocontrol agents has proved necessary to induce consistent levels of suppression on a commercial scale. The decomposition level (stability) of composts also affects suppressiveness. Immature composts serve as food for pathogens and increase disease even when biocontrol agents are present. On the other hand, excessively stabilized organic matter does not support the activity of biocontrol agents. Composts also may induce detrimental effects. For example, chemical factors may negate suppressiveness. Salinity and the concentration of nitrogen in composts are principal chemical factors to be considered.     

土壤质量生物学指标研究进展

本文对近年土壤微生物、土壤酶活性和土壤动物等土壤质量生物学指标研究成果进行了综合评述。土壤微生物是土壤有机组分和生态系统中最活跃的部分,被认为是最敏感的土壤质量生物学指标:微生物生物量代表参与调控土壤中能量和养分循环及有机物质转化所对应微生物的数量,但须结合多样性研究以弥补其无法反映土壤微生物组成和区系变化的缺陷;微生物群落组成和多样性动态反映土壤中生物类群的多变性和土壤质量在微生物数量和功能上的差异;土壤微生物活性体现在土壤微生物商、微生物呼吸和代谢商等方面,应考虑生物量大小与微生物种群活性间的相关关系以反映微生物种群内的差异。土壤酶活性具有极高时效性,在较短时间内就能反映出土壤质量的变化。土壤动物通常以种类的组成和数量,土壤动物区系的相对丰度、多样性或活性作为评价土壤生物质量的敏感指标。与土壤理化指标相比,土壤生物学指标更能对土壤质量的变化做出灵敏迅速的响应,因而被广泛地用于评价土壤质量。     

Biodegradation of Organic Matter During Mechanical Biological Treatment of MSW

The German Technical Guideline for Municipal Solid Waste (TASI) stipulates criteria for waste to be landfilled in order to minimize environmental hazards and landfill maintenance. One of these requirements is an ignition loss of less than five percent dm (dry matter). Only waste which has been incinerated can comply with this criterion, and subsequently be landfilled. Experts agree that the ignition loss alone is not suitable to predict reactions in a landfill. Therefore, other methods of assessing biological activity of processed MSW in a landfill are presented and discussed. It was found that respiration activity was most appropriate for such an assessment at this stage. From available data, it was concluded that processed MSW is fit for landfilling if the respiration activity is below 5 mg O₂/g dm over a period of 96 hours.     

Effect of MSW Compost on Microbiological and Biochemical Soil Quality Indicators

This laboratory incubation study was conducted to evaluate the effect of municipal solid waste compost (MSWC) as a soil amendment on soil quality indicators, such as microbial biomass, and their activities. The MSWC was compared against cow dung manure (CDM), a traditional organic supplement. The comparative study was carried out in water regimes of 60% water holding capacity (WH) of soil and under waterlogged (WL) condition. MSWC was applied to an alluvial soil (Typic Fluvaquent) at the rates of 0, 2.5, 10, 20 and 40 and CDM at 0, 20 and 40 t/ha. Microbial biomass-C (MBC), glucose induced soil respiration (SR), urease and acid phosphatase activities in soil were analyzed following 15, 30, 45, 60, 90 and 120 days of incubation. The parameters studied were significantly higher in CDM-treated than in MSWC-treated soils. Increase in graded doses of MSWC from 2.5 to 40 t/ha substantially increased the MBC, SR, urease and phosphatase activities in the soil. In 60% WH regime, MBC and SR increased for the first 30 days of incubation and then declined. Under the WL regime, the MBC declined while SR increased from 15 days till 120 days of incubation. Urease and phosphatase activities of soil increased for up to 60 days during incubation in 60% WH regime and then decreased. Activities of both the enzymes under WL regime decreased progressively during incubation. There were no negative impacts on the soil quality indicators from high application rates of MSWC.     

Biological Stability: A Multidimensional Quality Aspect of Treated Water

Regrowth processes in drinking water distribution systems may lead to hygienic, aesthetic and technical problems. These complex processes depend on interactions between micro-organisms and (i), compounds serving as energy sources; (ii), environmental conditions (temperature, hydraulics) and (iii), physico-chemical processes (sedimentation, corrosion, disinfection), respectively. The concentration of growth-promoting compounds is considered as the main driving force for regrowth and a large variety of tests has been developed to assess the growth-promoting properties of treated water. These methods range from determining the decrease of the concentration of dissolved organic carbon in a batch test to the assessment of the Biofilm Formation Rate (BFR) in a flow-through test. Biostability assessment of treated water in the Netherlands includes the AOC test in combination with the BFR test. The growth-promoting properties of synthetic materials in contact with treated water are determined with the Biofilm Formation Potential (BFP) test. A complete understanding of regrowth processes enabling to define appropriate control measures requires further research including: (i), the effect of reactive surfaces on the availability of slowly degradable compounds, and (ii), improvement of mathematical models describing regrowth processes.     

城市污泥与玉米秸秆堆肥中多环芳烃(PAHs)的研究

将城市污泥与玉米秸秆进行自然通风堆肥处理，应用GC/MS检测方法对污泥堆肥中的多环芳烃化合物(PAHs)进行了分析。污泥堆肥中PAHs的含量较低，ΣPAHs和ΣPAHs_carc分别为0.561 mg/kg和0.107 mg/kg，绝大部分PAHs化合物的含量低于0.050 mg/kg，含量较高的主要是中、低分子量的化合物。PAHs的降解效果显著，ΣPAHs和ΣPAHs_carc的降解率在80%左右，绝大部分化合物的降解率在50%以上，中等分子量的3个和4个苯环的化合物的降解效果相对较好。污泥堆肥中PAHs的含量、分布模式及其降解效果与原污泥中PAHs的特征密切相关。     

High Quality Composts by Means of Cocomposting Of Residues from Anaerobic Digestion

Advanced treatment of residues from anaerobic digestion of leftovers and kitchen waste originating from an industrial waste treatment plant was carried out by means of cocomposting in order to reveal potential synergistic effects. After a retention time of two weeks in the anaerobic reactor, microbial activity of the residues remained high. The biogas produced is of use in combined heat and power generation. Lab-scale experiments in the liquid phase have demonstrated “cracking” of the anaerobic stabilized organic matter under aerobic conditions. The advanced aerobic treatment of residues from anaerobic digestion by means of cocomposting leads to high quality composts. The addition of output material to biowaste from the separated bin collection may improve the formation of humic substances. Extractable humic acids are considered to represent a reliable parameter in describing high quality composts. Thus, the improvement of humic acid formation by means of composting is a goal to be achieved. Process control was performed by assessing parameters such as loss of ignition, total organic carbon, nitrogen and humic acid content as well as by modern analytic methods like FT-IR spectroscopy and thermogravimetry.     

Nitrogen Supplemented Cocopeat-Based Organic Wastes as Potting Media Mixtures for the Growth and Flowering of Chrysanthemum

Growth and flowering characteristics of chrysanthemum (Dendranthema grandiflora) was evaluated in organic wastes comprising burnt rice husk ash (RHA) and composted sewage sludge (SS) amended with differential proportions of soil:cocopeat (CP) in 0%, 25%, 50%, and 75% each on dry weight volume basis. The media mixtures were supplemented with varying nitrogen (N) levels (0, 2, 4, and 6 g N per pot). Utilizing CP as an amendment with the organic media considerably improved the physical as well as chemical properties of the potting media that was found desirable for the root zone environment in a finite volume of a pot. Chrysanthemum plants produced in increasing proportions of CP were observed to be well anchored and exhibited excellent quality of flowers. Utilizing 50% CP and 25% soil as a growing media amendment in SS (25%) proved to be the best media mixture for ideal growth and performance of potted chrysanthemum. Better aggregate stability provided by the SS and increased potassium (K) content in CP coupled with improved physical root zone environment provide a suitable reason to utilize CP as an amendment in potting media for an ideal display of pot mums.     

Biological and Artificial Matrixes as PAH Accumulators: An Experimental Comparative Study

In order to find out a new effective accumulator of polycyclic aromatic hydrocarbons (PAHs) useful for monitoring studies on a large scale and low costs, the accumulation capacity of both biological and artificial matrixes (mosses and polyester fibers, respectively) has been tested. For this purposes, Hypnum cupressiforme and dacron® were exposed to pollution airborne in two sites located nearby an active iron industry and in center of the town of Trieste, where high PAH pollution spots, due to vehicular traffic, are usually detected. The samplers were exposed in six sampling sessions for 21 days. The results obtained were compared with data collected by active PAH samplers, usually employed for official widespread monitoring. The level of correlation between the data sets was calculated. Furthermore, a repeatability study of data was performed. According to the results, both matrixes are good PAH accumulators, though they show different skills.     

Comparative Assessment of Enzyme Activities and Characteristics during Composting of Two Types of Composts

Characteristics in composts were determined during composting of chitinous source-amended compost (Cscom) and no chitinous source-amended compost (Ncom). At the end of the composting, moisture content, organic matter (OM), total nitrogen (T-N), and carbon to nitrogen ratio (C/N ratio) decreased in both the composts, whereas the phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) content increased. pH of the compost was adversely changed with electrical conductivity (EC). Enzyme activities declined until the end of composting except phosphatase. In the final-stage, Cscom has higher number of chitinolytic bacteria than in Ncom. One bacterium predominant was isolated and identified as Bacillus licheniformis. Growth of the plant pathogens were suppressed by Cscom and Ncom water extracts, with the suppression being higher in Cscom. Paenibacillus ehmensis, known for high antifungal potential, was isolated from Cscom. From our study, it can be concluded that amendment of chitin material improves the chemical, biological properties, and disease suppression ability of compost.     

Relationship of Soluble Salts Content in MSW Compost Media and Rooting of Evergreen Cuttings

Municipal solid waste (MSW) compost media with various levels of soluble salts were used for rooting stem cuttings of nine evergreen landscape shrubs: Buxus sempervirens L. ‘Green Gem’; Juniperus chinensis L. ‘Hetzii; J. chinensis ‘Mint Julep’; J. chinensis ‘Pfitzeriana Aurea’; J. horizontalis Moench ‘Bar Harbor’; J. horizontalis ‘Blue Chip’; J. sabina L. ‘Blue Danube’; Taxus x media Rehd. ‘Densiformis’; and Thuja occidentalis L. Rooting occurred during the winter in greenhouse compartments supplied with bottom-heated benches filled with 100% sphagnum peat or 100% perlite, or peat or perlite mixed with 15, 30, 45, 60 or 75% by volume of MSW compost. The electrical conductivity (salt) levels were similar in MSW compost with peat or with perlite (range, 0.05-0.60 dS·m^?1 with 0-75% compost) and positively correlated with levels of MSW (r = 0.88, P≤0.001). With few exceptions, cuttings rooted similarly in MSW with peat or perlite. Depending on taxa, increasing salt levels had various degrees of diminutive, neutral, and enhancing effect on rooting response, expressed in terms of percent rooting, root number per cutting, and root length (longest root per cutting). Four taxa (J. horizontalis ‘Bar Harbor’ and ‘Blue Chip’, J. sabina ‘Blue Danube’, and T. occidentalis) were tolerant of the salt levels tested (positively influenced or unaffected). The other five taxa were intolerant (adversely affected).     

Use of Spent Coffee Ground Compost in Peat-Based Growing Media for the Production of Basil and Tomato Potting Plants

A spent coffee ground compost (SCGC) was evaluated as an alternative component of growing media to partially replace commercial peat (CP) and fertilizers in the production of potted plants. Seven mixtures (CP 100% + solid mineral fertilizers, CP 100% + liquid mineral fertilizers, CP 90% + SCGC 10%, CP 80% + SCGC 20%, CP 70% + SCGC 30%, CP 60% + SCGC 40%, and CP 100% without fertilizers) were compared for the production of basil and tomato potted plants. SCGC used in a proportion up to 40% enhanced the general plant stand by affecting the dry weight and the measured foliar parameters. Tomato and basil recorded good growth rates on SCGC-amended media, showing quality indices similar to those obtained under fertilization, evidencing compost plant nutrition provision. SCGC appears to be suitable for application as a partial peat substitute in the production of potted plants.     

Compositional Changes in Composts During Composting and Mushroom Growth: Comparison of Conventional and Environmentally Controlled Composts from Commercial Farms

Samples from conventional and environmentally controlled (EC) composts taken at various stages of composting and mushroom (Agaricus bisporus) growth were analyzed for changes in 80 percent ethanol and water extracts, monosaccharides in acid hydrolysates of polysaccharides, lignin concentrations and lignin structural features. The relative lignin content of all composts as measured by the acetyl bromide procedure increased, both during composting and mushroom growth. On the assumption that the absolute amount of lignin remains unaltered during composting and mushroom growth, the relative changes to the polysaccharide concentrations were calculated. Thus, during composting, 70, 53 and 58 percent of the initial wall polysaccharides for conventional, “cold” and “hot” EC, respectively, were consumed by compost microorganisms. During spawn running and fruiting, about 15 percent of wall polysaccharides were utilized from all types of composts. Thus, considerable amounts (17–31 percent) of polysaccharide remained at the end of mushroom production. During composting, there were changes in the degree of condensation and in the extent of oxidation of the lignins in all cases, but the rate and extent of these changes was dependent on the different composting regimes. During mushroom growth, further changes occurred, again with different patterns for the different compost types.     

Comparative Study on Biowaste Definition: Effects on Biowaste Collection,Composting Process and Compost Quality

A comparative study was run during 13 months on two biowaste definitions involving both lab tests and field surveys. A narrow biowaste definition, allowing only biogenic wastes (kitchen and garden waste) and referred to as ‘Biowaste,’ was compared to a broad biowaste definition, referred to as ‘Biowaste Plus’ and including man-made products, such as nonrecyclable wastepaper and diapers. Two similar test areas, each with about 425 inhabitants, were defined in a semiurban area north of Antwerp. During the entire test period, the amount of curbside waste (i.e., biowaste and restwaste or ‘grey waste’), was continuously measured and analyzed regularly (twice per season) for composition. At the start, middle and end of the test, the population of each test area was surveyed. Bench-scale aerobic composting experiments were run to evaluate the influence of both biowaste definitions on the composting process and the compost end product.

The introduction of source separated waste collection resulted in an overall landfill diversion rate of 43 percent for the (narrow) ‘Biowaste’ definition and 46 percent for the (broad) ‘Biowaste Plus’ definition. The contamination of biowaste with restwaste was low for both definitions (about three percent). Assuming that the collection and the appropriate disposal of organics could be improved to 95 percent efficiency (compared to about 60 percent currently), the landfill diversion rate could be increased to 59 percent for the ‘Biowaste’ and 74 percent for the ‘Biowaste Plus’ definition. Whereas the average sorting efficiency of separately collected organics was about 61 percent; 49 percent for nonrecyclable paper; and as low as 20 percent for certain categories of nonrecyclable paper (e.g., nonrecyclable cardboard packages). Apparently more education or a better systém of recognition and identification is needed to improve the collection efficiency of man-made compostables. Indeed, for easily recognizable products such as diapers, the sorting efficiency was as high as 70 percent.

The acceptance and goodwill of the population was significantly higher for the ‘Biowaste Plus’ definition, especially in the summer months. The yearly, overall composition of the total curbside waste (biowaste and restwaste combined) was 17 percent kitchen organics, 47 percent yard waste, four percent recyclable paper, 13 percent nonrecyclable paper and 19 percent noncompostables. It must be mentioned that glass, paper and large yard waste were collected separately by a voluntary bring-system. Biowaste Plus typically contained 16.0 percent paper (of which 2.9 percent was recyclable) versus 2.0 percent for Biowaste (0.3 percent recyclable).

The ‘Biowaste Plus’ definition resulted in improvements for the aerobic composting process due to easier moisture control, better aeration and a more tempered pH evolution. A significant difference was seen for NH₃ and corresponding odor emission, both being much lower with ‘Biowaste Plus.’ The quality of the compost produced was similar and acceptable for both biowaste definitions, according to existing standards (VLACO in Flanders and RAL in Germany).     

Utilization of Agricultural Waste Compost as an Alternative Potting Media Component with Coir Dust for Leafy Vegetable Ipomoea Acquatica

The aim of this research was to study the potential utilization of an alternative potting media developed from agricultural waste compost in combination with coir dust on the growth and development of leafy vegetable Ipomoea aquatica (L). Agricultural waste compost was prepared from poultry litter, sawdust, rice straw, gliricidia, and cow dung. Seven different potting media were prepared by mixing compost at the rates of 0%, 10%, 25%, 50%, 75%, and 100% with coir dust at the rate of 100%, 90%, 75%, 50%, 25%, and 0%, respectively. Developed potting media showed adequate physical and chemical properties for Ipomea aquatica cultivation. Crop yield showed significant differences among all treatments and treatment with 100% compost gave the best growth and yield parameters. The highest plant height, shoot fresh weight and shoot dry weight obtained from the 100% compost were increased by 2.70, 18.07, and 18.02 times in comparison to the 100% coir with chemical fertilizer control.     

A Four-Year Study on Influence of Biosolids/MSW Cocompost Application in Less Productive Soils In Alberta: Nutrient Dynamics

Composting municipal solid waste and biosolids and applying it on arable land have become an alternative way to treat waste in large municipalities in North America. However, cost of compost transportation and application constrains the compost use on the land further away from where it is produced. A four-year experiment was conducted (1998-2001) in less productive soils in Alberta to determine the effect of once in four year application of cocompost on soil nutrient dynamics and crop N uptakes. There were three crop blocks: barley (Hordeum vulgare L.), wheat (Triticum aestivum L), and canola (Brassica rapa), and they were rotated annually. The compost was only applied in 1998 at a rate of 50, 100 and 200 t/ha. Soil samples were taken in spring of every year after initial compost application to determine extractable N, P, K, S, Cu, Zn, Soil pH and EC. Each year, crops were harvested and N uptake was determined. Total concentrations of an array of heavy metals in the first year and fourth year after compost application were determined as well. The results showed that the release of N from the compost was high in the first year after compost application and then declined in each subsequent year. Similar to that release pattern was sulphur. The release of phosphorus from compost was steady throughout the four-year experimental time. Crop N uptake from compost application varied with crops and sites. The over all N use efficiency for three crops and two sites was 11%, 3%, 1% and 2% for the first and subsequent three years. The total heavy metal concentrations in the compost amended soils in the first and fourth year after compost application were similar, and they were below the standard of Canadian Fertilizer Act. Our results showed that N released from compost occurred mostly in the first two years after application, suggesting that an application frequency of once in every second year may be better than the once in every four year application strategy, especially with 100 t/ha application rate.     

堆肥中大肠菌群等粪便污染指标菌的残留状况调查

从日本九州地区23处堆肥化设施采集了以牛粪、鸡粪、污泥和餐厨垃圾为原料的堆肥试样29个,调查了大肠菌群等粪便污染指标菌的残留状况。结果表明,使用DESO培养基有11个试样被检出大肠菌群,检出率达38%,菌数在102~106 cfu.g-1的范围。使用API 20E鉴定系统对4个试样中的21个分离纯化菌株进行了菌种鉴定,发现有大肠菌群属的Escherichia coli、Escherichiavulneris、Pantoea sp.和Buttiauxella agrestis,以及非大肠菌群属的Serratia marcescens等肠内细菌科细菌。采用血清凝集试验对5株E.coli的病原性检测结果均为阴性。进一步针对6处堆肥设施的堆肥发酵过程中大肠菌群的消长追踪发现,大肠菌群数从原料到成品出现了逐渐减少直至消失、暂时消失、未完全消失、完全未检出4种走势,显示即使堆肥发酵温度在60℃以上,大肠菌群也有可能通过交叉污染等途径残留在堆肥成品中。     

百合试管苗的移栽对比试验

在含25μg/L多效唑手根培养基或结鳞茎培养基中培养后移栽,可显著提高百合试管苗移栽成活率,促进幼苗生长,其中以促进试管苗在试管内生成鳞茎再移栽途径的效果最好。鳞茎大小对幼苗生长有明显影响,以直径5－11mm的结磷苗进行去叶留根处理后,移栽效果最好。多效唑残留药效低。     

基于水质-水量的淮河流域生态补偿框架研究

淮河流域呈现水质型和水量型缺水状况。针对该流域现行生态补偿政策在实施过程中存在概念界定不清,区域局限性及补偿方式单一性的问题,在分析淮河流域水污染生态补偿政策实施现状的基础上,提出了基于水质-水量的生态补偿框架,并从核算标准、组织方式和补偿形式3个方面进行了分析和探索。分析结果表明,与淮河流域现行的生态补偿方式相比,该框架能够全面反映跨省、跨地区的水质和水量差异,可操作性和适用性更强、覆盖面更广。