Growth of Impatiens ‘Accent Red’ In Three Compost Products

Growth of Impatiens wallerana Hook. ‘Accent Red’ was evaluated in three composted urban waste materials (composted biosolids and yard trash (SYT): 20 percent biosolids/sewage sludge, 44 percent yard trimmings, and 36 percent mixed paper; composted refuse fuel residues with biosolids and yard trash (RYT): 74 percent refuse-derived fuel residuals, 10 percent biosolids/sewage sludge, and 16 percent yard trimmings; and composted municipal solid waste (MSW): 100 percent municipal solid waste). Treatments consisted of 100 percent composted waste and media in which the composted wastes were combined with control medium components at 60 percent, 30 percent, or 0 percent composted waste, by volume. Shoot dry mass of plants grown in SYT increased as the percentage of SYT in the medium increased, while shoot dry mass of plants grown in MSW linearly decreased from 1.24 g to 0.15 g. There were no significant differences in shoot dry mass of plants grown in different percentages of RYT. Initial medium soluble salt concentrations in MSW media were more than double concentrations measured in SYT and RYT media. Soluble salt concentrations in both the 100 percent and 60 percent MSW media exceeded 1.75 dS.m^?1, while the soluble salt concentrations in 100 percent SYT and 100 percent RYT were 0.50 dS.m^?1 and 0.61 dS.m^?1, respectively. The C:N ratios in 100 percent SYT and RYT were 17 and 15, respectively, while 100 percent MSW had a C:N ratio of 29. The relatively higher level of compost maturity as indicated by lower C:N and soluble salt concentrations contributed to superior growth of impatiens plants in 100 percent SYT and RYT compared to 100 percent MSW.     

Effect of A Waste Stream Component on the Agronomic Properties of Municipal Solid Waste Compost

Managing municipal solid waste (MSW) compost for agricultural use requires an understanding of waste stream components and how they affect the value of the finished product. We evaluated the influence of disposable diaper content in MSW compost because of the recent concern of the environmental impact of this product. To determine the potential effect of disposable diapers on MSW compost, the ‘normal’ concentration of soiled, disposable diapers in a waste stream was raised from 2 percent to 8 percent. Previous observations indicated that the diapers disassociated during in-vessel digestion and most of the components could not be distinguished from the primary compost. The objective of this study was to examine the effect of additional diapers on the agricultural value of mature MSW compost. Loamy sand and silt loam soils were amended with MSW compost at a rate of 20 percent. Comparisons between the two composts and their interactions with soil type were made on the basis of water retention characteristics; germination and emergence of corn, soybean, radish and lettuce; and yield and element uptake by corn and lettuce at two moisture regimes. Differences between the compost amended soils suggested that the primary benefits of additional diapers were increased nutrient availability and soil water retention, and the foremost concerns were excess total soluble salts and boron.     

Cumulative Effect of Annual Additions of MSW Compost on the Yield of Field-Grown Tomatoes

For three years, source separated municipal solid waste (MSW) compost was applied in the field at two rates (25 and 50 T/A) and planted with tomatoes. Average yield (lbs/plant) from plots amended with 50 T/A MSW compost was significantly greater all three years than the unamended controls. Yield from plots amended with 25 T/A MSW compost was significantly greater than the unamended control only in 1993. The average number of tomatoes per plant and the average weight of each tomato were also greater from the compost-amended plots. The addition of 50 T/A MSW compost for three years raised the pH of the soil from 5.8 to 6.4 and raised the percent organic matter 84 percent. The concentration of nitrate in plots amended yearly with 50 T/A MSW compost was three fold greater than the unamended control.     

菌、热及菌热联合对垃圾堆肥腐熟的比较分析

为研究菌剂、余热及其联合作用对堆肥腐熟度的影响,采用强制通风静态堆肥系统,以现有堆肥工艺为对照（CK）,比较研究了添加菌剂（T1）、余热利用（T2）、添加菌剂并利用余热（T3）3种工艺垃圾对堆肥过程中腐熟度的影响。结果表明：从温度、pH、电导率（EC）、腐植酸光学特性（E4/E6）、水溶性碳（WSC）、固相C/N和发芽率指数（GI）来看,4个处理均达到腐熟;添加菌剂（T1）对EC、E4/E6、WSC、C/N和GI有显著影响;除E4/E6、WSC和C/N外,循环热风（T2）对其余腐熟度指标有显著影响,菌剂和余热的联合作用可显著提高堆肥的腐熟度,且二者对堆肥腐熟度的影响是一种协同作用。     

Changes in the microbial activity of an arid soil amended with urban organic wastes

Changes produced in the biological characteristics of an arid soil by the addition of various urban wastes (municipal solid waste, sewage sludge and compost) at different doses, were evaluated during a 360-day incubation experiment. The addition of organic materials to the soil increased the values of biomass carbon, basal respiration, biomass C/total organic C ratio and metabolic quotient (qCO₂), indicating the activation of soil microorganisms. These biological parameters showed a decreasing tendency with time. Nevertheless, their values in amended soils were higher than in control soil, which clearly indicates the improvement of soil biological quality brought about by the organic amendment. This favorable effect on soil biological activity was more noticeable with the addition of fresh wastes (municipal solid waste or sewage sludge) than with compost. In turn, this effect was more permanent when the soil was amended with municipal solid waste than when it was amended with sewage sludge. Received: 28 May 1996     

Elemental Analysis of Municipal Solid Waste Compost II. Refuse Derived Fuel Unders

In utilizing municipal solid waste (MSW) as fuel for energy production, about 10 percent remains as a noncombustible small size fraction byproduct called refuse derived fuel unders (RDFU). We assessed the feasibility of using RDFU to produce compost for land applications, in the context of acceptable limits for metals. Periodic random samples from two batches of RDFU obtained during composting were analyzed for the heavy metals Cd, Cu, Pb, and Zn, and for the plant nutrients N, P, and K. The heavy metal content (mg/kg, dry weight) in all samples ranged from 1.7-12.7 (Cd), 201-3217 (Cu), 267-5002 (Pb), 344-2079 (Zn). The total variability of these elements within a batch of RDFU compost was high, with relative standard deviations (RSD) ranging from 20-107 percent. Estimates of the number of samples needed to obtain a 10 percent uncertainty in the averages ranged from 5-138, depending on the analyte and the compost batch. Leachability tests showed little leaching of metals in the RDFU compost. The high variability in heavy metal content and the excessive Pb concentrations in this RDFU may limit its use for composting.     

MSW Compost Reduces Nitrogen Volatilization During Dairy Manure Composting

Manures lose N through volatilization almost immediately after deposit. Attempts to control losses include the addition of a C source to stimulate nitrogen immobilization. Composting is a treatment process that recommends the addition of carbonaceous materials to achieve a C:N ratio of 30:1 to stimulate degradation and immobilize nitrogen. Dairies near cities may be able to reduce N loss from manures by composting with urban carbonaceous residues such as municipal solid waste (MSW) or MSW compost that, by themselves, have little agronomic value. Studies were conducted using a self-heating laboratory composter where dairy solids were mixed with MSW compost to determine the reduction of N loss during composting. One-to-one mixtures (v/v) of dairy manure solids and MSW compost were composted and NH₃ volatilization, CO₂ evolution and temperatures were compared to composting of manure alone. Addition of MSW compost resulted in increased CO₂ evolution and reduced N loss. Nitrogen loss from composting dairy manure alone was four to ten times greater than that from composting dairy manure mixed with MSW compost. Adjustment of the C:N ratio to 25 by adding MSW compost to manure appeared to be the major factor in reducing N losses.     

Effects of Compost Source and Timing of Fertigation Initiation on Growth of Potted Poinsettia

Treatment combinations of four poinsettia (Euphorbia pulcherrima) cultivars, 20 substrates, and three fertigation treatments were evaluated in a completely randomized block design. Poinsettia cultivars included ‘V-14 Glory’, ‘Red Sails’, ‘Lilo Pink’, and ‘Annette Hegg Top White’. The compost substrates were compost:peat:perlite blended (by vol.) at 2:3:3, 1:1:1, and 2:1:1 ratios. Sunshine Mix 1 and Pro Gro 300S were used as controls. Composts tested were those prepared from crab offal, lime and polymer-dewatered biosolids, municipal solid waste (MSW), yard waste, and poultry litter. Fertigation treatments were initiated on the week of potting, delayed one or two week after potting and applied once per week. Controls produced premium quality plants. Composts prepared from poultry litter, yard waste, polymer-dewatered biosolids, crab offal, and MSW produced good quality plants. Plant width in 25 percent compost treatments were greater than those in 50 percent compost treatments. Total number of branches, plant height, canopy diameter, and plant grade on plants treated with fertilizer on the first week were only three percent greater than in treatments where fertilizer application was delayed one or two weeks.     

Characterization of Organic Matter in Compost Produced with Municipal Solid Wastes: An Italian Approach

Stabilization of the organic matter of a static pile of compost from municipal solid wastes (MSW) under a forced-pressure ventilation composting system was followed for 55 days during winter season. The materials were analyzed according to the official methodologies required by Italian regulations regarding the quality of composts from MSW. The stabilization process of the organic matter was monitored using both the degree of humification (DH), i.e. the ratio between the humified fractions (HA + FA) and the total extractable carbon (TEC), and the electrofocusing technique (EF). The DH increased steadily in compost during stabilization process and converged asymptotically at the end of the period of composting. The EF analyses of the organic extracts of compost from MSW showed a definite trend in the humification process and confirmed the actual evolution of the organic matter composted.     

Reclamation of Saline-Sodic Soils with Gypsum and MSW Compost

The effectiveness of sequential application of gypsum followed by matured mixed municipal solid waste (MSW) compost was investigated for the reclamation of saline-sodic soils. Soil plots were treated with 50 dt/ha (dry tone/hectare) of gypsum, followed by the addition of matured MSW compost at the 50, 100, and 150 dt/ha with five replications for each treatment. A number of physical, chemical and biological properties were investigated. The results from different treatments were compared with the Tukey-Kramer method. The results of this study show that the sequential application of gypsum followed by matured MSW compost can effectively restore degraded soils suffering from high soluble salts and exchangeable sodium content.     

Needed: Regional Inventories of Organic Residuals

? As waste management planners seek to divert increasing amounts of materials from the municipal and commercial streams, the value of regions conducting inventories of organic residuals that could be composted becomes apparent. Since 1960, various research studies have analyzed the potential for applying urban wastes on agricultural lands, either directly or after composting. Specific studies described in this report were conducted in New Jersey, Maine and the Omaha, Nebraska — Council Bluffs, Iowa region.     

The use of urban organic wastes in the control of erosion in a semiarid Mediterranean soil

Abstract. A two year field experiment was carried out in a semiarid Mediterranean area in order to evaluate, the effect on soil erosion of adding different urban organic wastes: a stabilized municipal waste (compost), an unstabilized municipal waste, and an aerobic sewage sludge. All the treatments significantly reduced soil erosion, compared to the control soil. The soil amended with compost was the most effective treatment, reducing soil loss by 94% and runoff by 54%.     

Effects of tillage practice and repeated urban compost application on bromide and isoproturon transport in a loamy Albeluvisol

We quantified the effects of tillage practice and repeated compost (municipal solid waste compost, MSW, and co‐compost of sewage sludge and green wastes, SGW, compared with a control plot without compost addition, CONT) application on bromide and isoproturon transport into the tilled horizon of a loamy Albeluvisol. To do this we conducted field measurements of near‐saturated hydraulic conductivity (K), bromide and isoproturon leaching in column experiments and batch isoproturon sorption measurements. While the K measurements showed that tillage practice had the major effect compared with the different organic amendments, with greater conductivities measured after ploughing and smaller Kvalues measured after sowing, the column leaching experiments showed no statistically significant effect of either the tillage practice or the compost amendments. The batch sorption coefficient, K_d, of isoproturon increased in the order CONT < MSW < SGW, while the leaching of isoproturon for the MSW and SGW was either equal, retarded or quicker compared with CONT. Rate‐limited sorption of isoproturon in the CONT and SGW treatments columns was found, and the overall dissipation of isoproturon increased in the order CONT < SGW < MSW. It was suggested that irreversible sorption as well as degradation occured during isoproturon leaching.     

Evaluation of Field-Applied Fresh Composts for Production of Sod Crops

Application of compost to cropland potentially can use large quantities of compost and serve as an alternative to waste disposal into landfills. This study was conducted to evaluate the suitability of field-applied composts of mixed municipal solid wastes, biosolids, leaves, and agricultural wastes for production of wildflower and grass sods. The composts were applied one inch thick on the soil surface. In half the plots, the composts were left on the surface as a mulch and in the other half, composts were worked into the top two inches of soil. The effects of the composts on wildflower, grass, and weed germination and growth and on wildflower diversity and flowering were investigated for two growing seasons. Wildflower and grass quality did not differ whether the composts were applied as a mulch or incorporated into the soil. In the first year, limited growth in apparently immature biosolids-woodchips and mixed MSW composts was attributed to high concentrations of ammonium or soluble salts. The detrimental effects of biosolids-woodchips compost which had high initial ammonium-N concentrations remained into the second season. In the first season, N from composts or fertilizers stimulated weed growth and resulted in poor crop quality. In the second season, crops had a competitive edge over the weeds, and N from the compost improved crop quality. Wildflower diversity and total amount of bloom improved as the N status of the media increased. Weed control and mature compost with readily available N and low soluble salt concentrations are required for high crop quality in the first season.     

半干旱退化土壤中施入城市垃圾的长期效应研究

The addition of municipal solid wastes (MSW) is considered as a possible strategy for soil rehabilitation in southeast Spain. The objective of this study was to evaluate the long-term (17 years) effect of five doses of MSW addition on the microbiological, biochemical, and physical properties of semiarid soil. Increased values of several parameters that serve as indicators of general microbiological activity, such as, basal respiration, adenosine triphosphate (ATP) or dehydrogenase activity;microbial population size (microbial biomass C), and extracellular hydrolase activity related to macronutrient cycles, such as, urease, β-glucosidase, and N-α-benzoyl-L-argininamide protease, were observed in the amended soils. The highest MSW doses showed the highest values in these hydrolase activities. The incorporation of municipal waste resulted in a more dense development of the plant cover, 50% greater in higher doses than in the control treatment, which generated a substantial increase in several C fractions. Total organic carbon reached 12 g kg^-1 soil with the highest MSW doses, compared to 4.30 g kg^-1 soil in the control treatment. The physical properties of the soil were also improved, showing greater percentage of stable aggregates and water holding capacity. Positive correlation coefficients between C fractions and parameters related to microbial activity and aggregate stability were observed. Although these improvements were greater in the soils receiving the highest doses of organic amendment, the increases were not proportional to the amount added, demonstrating the existence of a threshold, above which an increase in the amount of organic matter added is not reflected in an increase in the soil's physical, biochemical, and microbiological properties. However, the addition of municipal solid wastes proved its suitability for improving soil quality, thereby indicating the potential of such an amendment, to prevent desertification in Mediterranean areas such as those studied.     

Effect of Municipal Solid Waste Compost on Mine Soils As Evaluated by Chemical,Biological And Biochemical Properties of Soil

Composts are increasingly used in land rehabilitation because they can improve soil quality and reduce the need for inorganic fertilizers. Their use contributes to an integrated approach to waste management by promoting recycling of nutrients and minimizing final disposal of organic residues that, due to their composition, can pose problems to agricultural soils. We investigated whether compost from mixed municipal solid waste (MSW) could be used to remediate two soils from a mine contaminated with trace elements. One of the soils was less acidic and had a greater content of Cu and Zn while the other had more Pb and a lower pH. The effect of MSW was evaluated by plant growth, trace element leachability, ecotoxicity of soil leachates, and biological and biochemical properties of soils. Growth of perennial ryegrass (Lolium perenne L. cv. Victorian) was stimulated in the MSW compost-amended soils compared with respective controls or with acidic soil when limed. After ryegrass had been growing for 119 days, the amount of water-extractable Zn was lower in MSW compost-amended soils, while the opposite was true for water-extractable Cu. Water-extractable Pb increased following MSW compost application to one soil and decreased in the other. The greatest dehydrogenase activity was obtained in amended limed soil, while the number of culturable bacteria and fungi and the activities of cellulase and β-glucosidase were similar in soil that was limed or following MSW compost application. In contrast, urease activity was repressed in limed or MSW compost-amended soils. Leachates from unamended soils were toxic towards Daphnia magna. Liming the very acidic soil led to a decrease in the toxicity of the leachate, but it was only in MSW compost-amended soils that ecotoxicity was no longer detected.     

Changes in Chemical,Physical and Biological Properties Of Passively-Aerated Cocomposted Poultry Litter And Municipal Solid Waste Compost

Cocomposting of poultry litter with municipal solid waste compost (MSW) was evaluated as a means to stabilize nitrogen and phosphorus in poultry litter and to produce a stable organic soil amendment. Four passively aerated compost piles were established by mixing fixed weight ratios of MSW and composted poultry litter (21:1, 6:1, 3:1, 1:1); moisture was adjusted to 50 percent by weight at pile establishment. These ratios represented a range of initial C:N (26-12) and C:P (150-50) ratios. Composting process parameters monitored over eight months included temperature, oxygen and moisture contents, pH, electrical conductivity, C:N:P ratios, microbial respiration and diversity. Initial feedstock ratios had no significant effect on temperature in the thermophilic phase of composting. After one year of composting, microbial respiration in 21:1 and 6:1 mixtures was high relative to 3:1 and 1:1 mixtures suggesting slow maturation in piles with high MSW content. Salmonella sp. and coliform organisms were detectable for up to 47 days. Results suggest that MSW has potential as a carbon feedstock for poultry litter composting when used in moderate amounts.     

The Impact of Various Contaminants on the Trace Metal Content of Compost

The trace metal content of municipal solid waste (MSW) compost affects the quality and potential end uses of the finished product. The impact of typical contaminants found in the organic fraction of MSW on the trace metal content of compost was investigated. Contaminants including alkaline batteries, galvanized nails, zinc-plated screws, copper wires, and electronic cables were exposed to a thermophilic composting process for three weeks. The increase in trace metal content in the compost product was measured at the end of the composting process. The results showed that low-quality alkaline batteries, galvanized nails, zinc-plated nails, and copper wires had a significant impact on the zinc, copper, arsenic, lead, and cobalt contents of compost. Copper wires showed the highest impact on copper content, which was 52% of the Canadian Council of Ministers of the Environment (CCME) Category A limit in the final compost. Galvanized nails contributed to final levels of zinc reaching 30% of the CCME Category A limit. To ensure that CCME Category A criteria can be achieved, it is recommended that contaminants made from bare copper or coated with zinc be removed from the composting feedstock.     

Assessing solid waste compost application as a practical approach for salt-affected soil reclamation

Abstract

A short-term pot experiment was made to evaluate the effectiveness of municipal solid waste compost amendment on salt-affected soil. Hordeum maritimum plants were cultivated in pots filled with a clay-loam soil containing 0 or 40 t ha^?1 of compost and irrigated with tap water at 0 or 4 g l^?1 NaCl. Soil properties and heavy metal (Zn^{2 +}, Pb^{2 +}, Cd^{2 +}) accumulation were investigated. Municipal solid waste compost application significantly increased the soil contents of carbon, nitrogen and potassium under both non-saline and saline conditions. Soil heavy metal concentrations increased substantially too, but the recorded values were below the toxicity limits. Interestingly, plants subjected to the salt–compost interaction were more vigorous, compared with those grown on non-amended soil. Altogether, our data indicate that short-term utilization of municipal solid waste compost at 40 t ha^?1 may be of potential interest in the perspective of the rehabilitation of salt-affected soils. Yet, it must be stressed that the present findings are preliminary and need to be further evaluated under field conditions before practical recommendations can be inferred.