Response of Four Container Grown Woody Ornamentals to Immature Composted Media Derived from Waxed Corrugated Cardboard

Four containerized deciduous ornamental shrubs [deutzia (Deutzia gracilis L.), silverleaf dogwood (Cornus alba ‘Elegantissima’), red-osier dogwood (Cornus sericea L.), and ninebark (Physocarpus opulifolius L.)] were grown during each of two separate growing seasons using 12 different immature (nonaged) composts as media (year one, 12 weeks from start of windrowing; year two, 16-weeks) and also two control nursery mixes (100 percent ground pine bark; and 80:15:5 by volume of pine bark:sphagnum peat:top soil). The compost formulations (volume basis) consisted of spent mushroom substrate (50 percent), waxed corrugated cardboard, 0 percent, 25 percent, or 50 percent), and/or pulverized wood wastes (50 percent, 25 percent, and 0 percent). Supplemental N was added to some composts as poultry manure (18 kg·m^?3), soybean wastes (24·kg·m^?3), or both at the same application rates. Despite the immaturity of the compost media and the presence of high initial contents of soluble salts primarily from the spent mushroom substrate (EC ≤6.4 dS·m?1, 1:1 v/v medium:water extracts), the top dry weight (averaged over two seasons) of each of the four species grown in compost media, regardless of waxed corrugated cardboard (WCC) level, exceeded that obtained in 100 percent pine bark. Compared with the 0 percent WCC compost, plants of all four species grew better in 25 percent and/or 50 percent WCC compost media and growth in these treatments was more (silverleaf dogwood), similar (deutzia and red-osier dogwood), or less than (ninebark) that in the 80:15:5 nursery mix. Rapid leaching of the potentially toxic soluble salts from the containerized compost media within days after planting minimized any adverse effects on the plants. There was no difference in foliar concentrations of N, P, K, Ca, Mg, Fe, Mn, and Zn due to WCC level, or to the N supplements which had little or no effect on growth. The foliar contents of heavy metals (Cu, Ni, Cr, Cd, Co, and Pb) were low and/or below detection limits.     

畜禽粪便复混肥研制及其肥效初探

利用猪粪、鸡粪及其垫料进行了高温堆肥化及有机一无机复混肥的研制和应用效果的初步试验。结果表明,堆肥化温度升至55℃以上保持了一周时间,达到了无害化要求;经过100d的堆制,堆肥基本腐熟。腐熟堆肥与化肥配制的有机一无机复混肥可明显促进玉米株高和生物量的增加,与对照相比,施用复混肥的玉米株高和生物量在中肥力土壤上分别增加了11．4％和71．8％,在低肥力土壤上分别增加了8．9％和43．2％;复混肥对水稻的生长促进作用非常明显,与对照相比,施用复混肥水稻的株高、分蘖数和生物量在中肥力土壤上分别增加了15．4％、58．5％和78．3％,在低肥力土壤上分别增加了29．4％、104．5％和247％。即在低肥力土壤上的促进作用高于中肥力土壤。     

Use of Sulfur to Control pH in Composts Derived from Olive Processing By-products

Two composts were prepared from olive press cake (OPC) repeatedly turned and moistened with either olive mill wastewater (OPC+OMW) or water (OPC+W). When phytotoxicity was drastically reduced and the pH of the composts had reached 8.6 and 7.55 respectively, elemental sulfur was added at 0.9% of dry weight to the OPC+OMW compost and at five different doses (0.1 – 1.0% of dry wt) to the OPC+W compost. During the following six months, an exponential pH decline was observed in both compost materials. The pH reached a final value of 5.8 in the OPC+OMW compost whereas a pH decline related to the amount of added sulfur was observed in the OPC+W compost (final values from 6.8 to 4.3). Over 80% of the pH decline occurred during the first two months following the sulfur addition. Sulfur was applied following the stabilization of the material in the case of OPC+W. No phytotoxic effects of the final products were observed at sulfur application doses up to 0.5% of dry compost weight, but a significant germination index reduction was observed at the 1% dose, probably related to the increased conductivity of the compost leachate. Sulfur was applied before stabilization of the compost material, in the case of OPC+OMW, to also investigate the effects of sulfur addition on the composting process. A thermophilic phase similar to that observed after the last OMW application exceeding 50°C followed, and no effects on microbial activity profiles of the compost were observed. The results indicate that small amounts of elemental sulfur may efficiently control high pH values in the final compost products and could be safely applied at late composting stages or after composting. This may broaden the utilization of these composts in potting media and alkaline soils.     

Effect of Five Municipal Waste Derived Composts on a Cereal Crop

Agricultural soils were amended with five mixed feedstock (four source segregated and one mechanical biological treatment) municipal waste derived composts to investigate the effect on a cereal crop over two years. Composts were applied at two rates to contain either 250 or 500 kg nitrogen ha^?1 and compared to a control which received no fertilizer. In year one, three of the composts increased barley yield (by up to 21%), compared to the control (no compost and no fertilizer) and two reduced it (by up to 33%). Application of the municipal waste derived compost resulted in greater nitrogen concentration in the grain and 1000 grain weight but reduced nitrogen uptake and yield. Application of composts had no significant effect on levels of lead, nickel and cadmium in the barley grains. Levels of soil potentially toxic elements were not significantly increased by application of the composts. In year two, all composts gave comparable or greater wheat yields in comparison to the control.     

Fate of 15N Derived from Composts and Urea In Soils under Different Long-term N Management In Pot Experiments

Understanding of dynamics of N derived from organic N sources in soil is required for the development of sustainable agricultural systems. The aim of this paper is to compare, using pot experiments, the fate of N from urea (UF) and organic N sources such as rice straw compost (RC) and cattle compost (CC) using ¹⁵N labeled materials in paddy soil planted with rice. Two soils with a history of long-term applications of chemical fertilizers (LTCN) and organic N sources, i.e. straw compost +soybean cake, (LTON), were also compared. Nitrous oxide emissions were monitored during the growing period. Yield and N uptake of rice were higher in LTON soil than LTCN soil with no significant interaction with N applications. Chemical fertilizer increased yield and N uptake with a recovery rate by rice of 36 to 45%. Nitrogen recovery from RC and CC by rice was less than 10%. When recovery of N in soil was included with that recovered in the plant, 70% and 61% of applied N in the UF treatment was recovered from the LTCN and LTON soils, respectively. In comparison, more than 95% of applied N was recovered in the plant and soil for the RC and CC treatments. There was a sharp increase in N₂O emission during the aerated period in nonplanted pots regardless of whether supplemental N was added, and this was associated with the increase in NO₃- in soil solution at 0.5 cm depth. There was a much lower N₂O emission in planted pots than nonplanted pots with no significant difference among the LTCN and LTON soils or the N treatments. The results indicated that the application of organic N source provided lower N supply to the plant than urea, but also could reduce N loss because of higher retention in the soil. Long-term continuous application of organic N sources enlarged the labile N pool without increasing N₂O emission. Nitrous oxide emission was important during the mid-season aerated period from pot experiments and was partly related to the concentration of NO₃- and the rate of nitrification.     

Physicochemical and Microbial Characteristics of Locally Processed Green Waste Composts

Four locally composted green waste composts (GWCs) namely Almukhasib, Growers, Plantex, and Super were screened to determine whether they meet the standards. All composts showed normal physical properties, except for the bad smell from sulfur reducing bacteria in Almukhasib compost, and light brown color Plantex. The germination indexes of the composts comparable to the standard (90%) were 98% for Plantex followed by Growers (77%), and 5% for both Super and Almukhasib. The chemical and physical properties vary considerably as follows: pH 3-10.5 (standard 5-8), electrical conductivity (EC) 0.4-10.2 mScm^?1 (standard 0.04.0 mScm^?1), moisture content (MC) 29-43.7% (standard 35-60%) and water holding capacity (WHC) 92-200%. Wide ranges in the chemical properties were expressed as total nitrogen concentration 5705-16401 mgkg^?1 (standard <500 mgkg^?1), organic matter 17-67.6% (standard 35%). Although, there are significant variations in the concentration of the heavy metals among the tested composts, the concentrations of these metals (Zn, Ni, Pb, Hg, As, Cd, and Cr) were lower than the recommended levels. The average of the bacterial colony forming unit per gram dry weight ranged between 464-2292 cfu/g, whereas the fungal cfu were 14-4308 cfu/g (standard < 1000 cfu/g). The most probable number (MPN) for coliform bacteria was 64-1549 cfu/g dry weight. Aspergillus niger was the predominant fungus recovered from all compost samples (100%) followed by A. fumigatus (50%), A. sparsus (50%), yeasts (50%), A. flavus (37.5%), and the remaining A. restrictus, A. ochraceous, Cladosporium spp., and Penicillium spp. is 25% each. The results showed that the physicochemical properties and microbial contamination of the screened composts were considerably varied and did not meet many of the acceptable limits in Oman, which render them unsafe for handling or unsuitable as direct fertilizer for plant growth or for soil bioremediation, which suggests mixing the composts with vermiculite and soil in order to improve their general characteristics. Therefore, there is evident need for urgent development of proper composting techniques, standard laboratory testing methods for high quality control measures, and adopting strong legislation. The use of certified and high grade mature green waste compost is a priority.     

Mineralogical Characteristics of Yellow- Red Soils Derived from Granite

Mineral constituents and their weathering in yellow-red soils derived from granite in middle and lower reaches of the Yangtze R iver were studied. Light minerals in fractions greater than silt contained over 80% quartz and feldspar, and heavy ones contained more than 60% various iron minerals and about 30% mica and hornblende. Kaolinite was the main clay mineral, the content of which was about 300 -400 g/kg. Quartz was weathered very weakly, Ca-feldspar was weathered over 65%, and about 25% of Na-feldspar was weathered. The vermiculitisation of mica was relativly obvious, > 50% of mica being weathered to vermiculite. Weatherable minerals were also obviously weathered, the weathering being about 60%. Soil vermiculite was evolved through the process of mica→hydromica→vermiculite-chlorite→vermiculite, which was closely related to leaching situation and oxidic condition.     

不同母质发育旱地土壤反硝化功能差异及其关键影响因素

农田土壤反硝化作用强度具有较高的空间异质性,不同类型土壤反硝化作用活性的影响机制可能存在差异。本研究通过大规模样带调查,系统采集了3种不同母质发育的旱地农田土壤,对比分析了土壤反硝化能力的差异及其与土壤环境因子的关系。结果发现:土壤反硝化势在3个类型土壤间有显著差异,其中河流冲积物发育的潮土(AS)反硝化势(以单位时间单位质量土壤的N2O释放量表示)显著高于其他两个类型土壤22.22～579.09μg/(kg·h),平均高达213.34μg/(kg·h),黑土(BS)的反硝化势平均为136.38μg/(kg·h),略高于第四纪红色黏土发育的红壤(QRCS)(96.17μg/(kg·h)),但两者无显著差异。相关性分析表明,土壤pH与反硝化势极显著正相关,说明在本研究所测定的土壤性质中,pH可能是影响不同类型土壤反硝化势差异的关键因素,另外,有机质含量对3个类型土壤反硝化势也有一定影响。同一母质发育的土壤,反硝化能力在不同采样地点也存在差异,而且调控不同类型土壤内部反硝化势的关键土壤环境因素不尽相同,其中对第四纪红色黏土发育的红壤、潮土和黑土影响最为显著的因素分别为土壤有机质、pH和黏粒含量。     

不同母质发育土壤的中红外吸收光谱特征

选取湘东丘陵区四种典型母质发育土壤(酸性紫色土、花岗岩红壤、板岩红壤和第四纪红土红壤),采集剖面(深至母岩/母质层)样品,应用傅里叶变换红外光谱仪研究灼烧去除有机质处理、土层深度和母质类型对土壤中红外吸收光谱特征的影响,分析吸收光谱与土壤理化性质的关系。结果表明,去除有机质后,特征区的中红外吸收值升高,反映矿物质对红外吸收谱线的强烈影响。在剖面上,底土(60~80 cm或100~120 cm)的中红外吸收值高于表土(0~20 cm),与土壤有机质含量的剖面分布相反。四种土壤的中红外光谱均属典型的高岭石图谱。砂粒、粘粒含量与红外吸收值的相关性最好,砂粒含量的最大相关系数(0.51)出现在3700、913和720~540 cm~(-1)附近,粘粒含量的最大相关系数(0.54)出现在1100~694 cm~(-1);本研究表明,原土的中红外吸收光谱特征主要受矿物质的支配,可以很好地反映土壤质地的状况,指示土壤质量变化。     

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.     

Physical Characteristics of Miscanthus Composts Compared to Peat and Wood Fiber Growth Substrates

The physical parameters of four different Elephant grass “Miscanthus ogiformis” ‘Giganteus’ composts and four of the most used types of peat products in Denmark, along with a wood fiber growing medium (Culti), were compared to determine possible physical differences, and to test whether compost could be used as an alternative substrate to peat. The Miscanthus straw was composted with three different N sources: ammonium sulfate, liquid pig manure and urea plus tap water (as a control). Compared to peats, the composts tested had low total bulk density, high air-filled porosity and a high diffusion coefficient of oxygen. None of the 9 products tested had the optimum levels of all the different physical parameters. Mixing the tested compost and peat will possibly increase the air-filled porosity of the substrates compared to pure peat, and brings the substrates physical parameters closer to the ideal recommended range. These compost media require further investigation before they can be used directly as an alternative to peat in greenhouse production.     

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.     

Study on Sorption Characteristics of Uranium onto Biochar Derived from Eucalyptus Wood

In this study, the sorption characteristics of U(VI) onto eucalyptus biochar as a function of various operating parameters such as solution pH, initial metal ion concentration, contact time and ionic strength of the medium are reported. Biochar was characterised using various techniques such as CHNS element analysis, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). SEM analysis showed the presence of micro- and macropores in the sorbent, and FTIR spectra confirmed the presence of functional groups like carboxylic (?COOH), hydroxyls(?OH), carbonyls(–C=O), etc. Maximum sorption of about 95% is found to occur in the pH range of 5 to 6. U(VI) sorption onto biochar reached equilibrium within 20 min at pH 5.5. The kinetic data were analysed using both pseudo-first-order and pseudo-second-order kinetic models, and the latter is found to be more appropriate to explain the observed kinetics. The equilibrium data were correlated with Langmuir and Freundlich models, and the maximum monolayer adsorption capacity obtained from the Langmuir model was 27.2 mg/g at 293 K. From EDS, FTIR and XPS measurements, it is found that the sorption process involves chemical interaction between the U(VI) and the surface functional groups on the adsorbent. Efficient removal of low level of uranium from ammonium diuranate supernatant demonstrates its utility as sorbent for waste water treatment.     

巫山黄土成因及其发育土壤特征研究

  目的  为探明巫山黄土成因,了解该类母质发育土壤的发生学特征。  方法  以典型巫山黄土及其发育土壤剖面为研究对象,通过野外调查采样和室内分析,详细考察剖面形态、颗粒组成、常量元素地球化学特征及其他相关理化性质,计算探讨硅铝率（ Sa ）、化学蚀变指数（ CIA ）、钠钾比（ Na/K ）、铁游离度等风化指标。  结果  （1）巫山黄土的颗粒组成以粉粒为主,平均含量为53.29%,与典型风尘沉积物相似,同时,巫山黄土与其他区域风成黄土的主要元素硅、铝、铁含量非常接近,上陆壳（UCC）标准化曲线也较为相似;（2）该剖面100 ~ 140 cm深度与其他深度相比,有机碳和硒含量较高,CaCO₃相当物含量和δ13C值较低,推测在此深度堆积过程中的气候较为温湿,并可能出现过植物的生长;（3）巫山黄土剖面的 Sa 为8.73 ~ 9.17、 CIA 为65.96 ~ 69.10、 Na/K 为0.74 ~ 0.89、铁游离度为22.88% ~ 29.74%,与其他地区风成黄土相比,巫山黄土风化程度强于洛川黄土而弱于下蜀黄土和成都黏土,与汉江黄土和甘孜黄土十分接近。  结论  巫山黄土应为风积成因,处于中等化学风化程度,以脱盐基为主,脱硅富铁铝化程度弱,可能与汉江黄土或甘孜黄土同源。     

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.     

Microbial Diversity and Bioactive Substances in Disease Suppressive Composts from India

The present study aimed to investigate microbial communities in seven Indian composts and their potential for biocontrol of Fusarium oxysporum f. sp. lycopersici. In addition, identification of bioactive substances in disease suppressive composts was also attempted. Composts were chosen based on disease suppressiveness and subjected to molecular microbial analyses. Total genomic DNA from the composts was extracted and amplified with polymerase chain reaction using primers targeting the 18S rRNA and 16S rRNA genes of fungi and bacteria, respectively. Denaturing gradient gel electrophoresis (DGGE) fingerprinting and DNA sequencing were used to identify the fungal and bacterial targets. Phylogenetic analysis of the fungal 18S rRNA ITS gene sequences showed that phylum Ascomycota was dominant in all composts, while in the bacterial 16S rRNA gene sequences, the phylum Proteobacteria was dominant. Some fungi in disease suppressive composts grouped phylogenetically close to F. oxysporum. Bacterial sequences with close similarity (>95% identity) with Actinobacterium showed a strong presence only in disease suppressive composts. Disease suppressive composts formed a separate group in the cluster analysis of 18S rRNA ITS and 16S rRNA gene sequences. Gas chromatography-time of flight-mass spectrometry was performed with compost extracts to determine if bioactive substances were present in disease suppressive composts. The analysis of compost organic matter showed a negative association of disease suppressiveness with phloroglucinol, sitosterol, and monoenoic fatty acid, while cholesterol and certain organic acids were positively associated with suppressiveness.     

重庆市更新统沉积物发育土壤的特性及分类

选取重庆市境内分别由夹卵石黄色黏土(PC)、黄色黏土(YC)、红色黏土(RC)等更新统沉积物发育的6个典型旱地和水田土壤剖面为研究对象,探讨其土壤特性及系统分类归属。结果表明,PC发育的旱地土壤富含砾石且无铁锰斑纹,YC发育的旱地土壤不含砾石但有铁锰斑纹,RC发育的旱地土壤耕作层以下黏粒淀积明显。在PC和YC发育的水田土体内,上部土层的有机质累积明显且彩度较下部低,游离铁在下部土层有明显聚积,而母质为RC的水田土体内游离铁则迁移不明显。3个旱地土壤分别被划归为普通简育湿润雏形土、普通铁质湿润雏形土和红色铁质湿润淋溶土3个亚类,3个水田土壤则分别被划归为普通铁聚水耕人为土和普通简育水耕人为土2个亚类,共可建立6个土族和6个土系。YC发育的普通铁质湿润雏形土有铁锰斑纹存在,这是古水文条件的反映,现已完全脱离地下水的影响,故不再具有潮湿土壤水分状况;沉积物特征、区域气候等会影响旱地土体内黏粒的淋溶淀积,进而影响其土纲划分;水耕活动使更新统沉积物发育的雏形土和淋溶土演变为水耕人为土;地块筛选、坡改梯、拣拾等人为活动会显著减少PC发育的水田土体内砾石含量,影响其土族控制层段的颗粒大小级别判定。     

Effects of Different Types of Composts on Soil Characteristics and Morphological Traits of Two Dry Rangeland Species

Today, environmental protection and safe crop production are very important. The management of soil elements by compost is considered as important for sustainable agriculture. The mode of action of the composts is very different between various plant species. To evaluate the effects of different composts on soil structural and chemical properties and on morphological traits of two dry rangeland species (atriplex; Atriplex lentiformis and mesquite; Prosopos juliflora), a study was conducted in Fars Province of Iran during the year 2010. The study was a factorial experiment based on a randomized complete block design with three replications. Treatments included compost types: solid (SC) and liquid compost or compost tea (LC), solid-liquid mixture (XSL) and control (Con; non used compost) as the first factor, and two pasture plant species as the second factor. The results showed that the compost application had significant and positive effects on morphological traits such as plant height, stem diameter, plant volume, crown length, width, and area, and caused 15, 51.18, 70.67, 34.18, 18.35, and 64.94% increase on these morphological traits, respectively. Although soil acidity was not significantly affected by compost and species, the effects of compost were significant on organic matter percentage, soil phosphorous, and potassium contents. Soil nitrogen percentage was affected by both species and compost. Compost application caused a decrease in the amount of sodium compared with the control. Overall, the results of this study suggested that within the compost types, liquid compost was an advisable biofertilizer in a similar climate. Furthermore, the LC and the XSL are recommended for improving the morphological traits and the soil characteristics, respectively.     

广东不同母质水稻土供钾特性的评价

应用生物耗竭法并结合模拟试验综合评价了广东5种主要母质发育水稻土的供钾特性。研究结果表明:(1)2mol/L冷HNO3法提取的有效钾与水稻吸钾量间的相关性最好,建议用2mol/L冷HNO3法提取的钾来评价土壤的供钾状况。(2)1mol/L沸HNO3法提取的非交换性钾含量在耗竭后高于耗竭前的水平,与水稻吸钾量相关性很小或呈负相关,不适宜用来评价耗竭土壤。(3)广东5种主要母质发育的水稻土供钾能力大小顺序为:三角洲沉积物发育水稻土>花岗岩发育水稻土>砂页岩发育水稻土>石灰岩发育水稻土>玄武岩发育水稻土。该试验结果可供水稻合理施用钾肥作参考。     

Stability Evaluation of Mixed Food Waste Composts

As interest in food waste composting grows, so does the need for proven composting methods. Stability testing has been proposed as a compost quality assurance tool. We conducted this study to: (i) to evaluate the efficacy of simple outdoor composting methods in producing a compost with a low, stable decomposition rate, and (ii) to determine the reliability of simple, 4-h compost stability evaluation methods. Composting was conducted outdoors in winter and spring in Eugene, Oregon without moisture addition. Mixed food waste was combined with screened dairy solids and ground yard trimmings. Sawdust was used to cover windrows for the first 27 d of composting. Compost windrow temperatures remained above 55°C for 30+ d. Carbon dioxide evolved with several 4-h test methods was strongly correlated (r² > 0.7) with CO₂ evolved using a 48-h test. A limited-turn windrow (LTW) composting system produced compost with slightly greater stability than a passively aerated windrow (PAW) composting system. Food waste compost samples had a low CO₂ evolution rate after 71 to 99 d using either composting system. Compost CO₂ evolution rate at 25°C decreased with composting time, reaching approximately 1 to 4 mg CO₂-C g compost C^?1 d^?1 for the PAW method and 0.5 to 2 mg CO₂-C g compost C^?1 d^?1 for the LTW method. Putrescible organic matter in food waste was effectively decomposed in outdoor windrows using composting methods that did not employ forced aeration, self-propelled windrow turners, or manufactured composting vessels. Several 4-h stability tests showed promise for implementation as quality assurance tools.