Biological,Chemical and Physical Properties of Composted Yard Trimmings as Indicators of Maturity and Plant Disease Suppression

A full scale system for composting of fermented, odiferous yardwaste trimmings was developed that produced a stabilized compost, minimized odor generation and prevented leachate formation. Characteristics of the compost highly significantly correlated with composting time included availability of the plant nutrients K, P, Ca and Mg, electrical conductivity, total carbon to nitrogen ratio, cation exchange capacity, stability based on O₂ respirometry, and finally, nitrate-nitrogen concentration. Radish was a good indicator of compost maturity. As the compost matured, suppressiveness to Pythium damping-off increased but it remained conducive to Rhizoctonia damping-off.     

Soil Physical Properties and Organic Matter Fractions Under Forages Receiving Composts,Manure or Fertilizer

A field study was conducted to assess the benefits, with respect to soil physical properties and soil organic matter fractions of utilizing composts from a diversity of sources in perennial forage production. A mixed forage (timothy-red clover (Trifolium pratense L.) and monocrop timothy (Phleum pratense L.) sward were fertilized annually with ammonium nitrate (AN) at up to 150kg and 300 N ha^?1 yr^?1, respectively, from 1998-2001. Organic amendments, applied at up to 600 kg N ha^?1 yr^?1 in the first two years only, included composts derived from crop residue (CSC), dairy manure (DMC) or sewage sludge (SSLC), plus liquid dairy manure (DM), and supplied C to soil at 4.6 and 9.2 (CSC), 10.9 (SSLC), 10.0 (DMC) 2.9 (DM) Mg C ha^?1. Soil samples (0-5cm; 5-10cm;10-15cm) were recovered in 2000 and 2001. Improvements in soil physical properties (soil bulk density and water content) were obtained for compost treatments alone. Composts alone influenced soil C:N ratio and substantially increased soil organic carbon (SOC) concentration and mass (+ 5.2 to + 9.7 Mg C ha^?1). Gains in SOC with AN of 2.7 Mg C ha^?1 were detectable by the third crop production year (2001). The lower C inputs, and more labile C, supplied by manure (DM) was reflected in reduced SOC gains (+ 2.5 Mg C ha^?1) compared to composts. The distribution of C in densiometric (light fraction, LF; >1.7 g cm^?3) and particulate organic matter (POM; litter (>2000μm); coarse-sand (250-2000μm); fine-sand (53-250μm) fractions varied with compost and combining fractionation by size and density improved interpretation of compost dynamics in soil. Combined POM accounted for 82.6% of SOC gains with composts. Estimated compost turnover rates (k) ranged from 0.06 (CSC) to 0.09 yr^?1 (DMC). Composts alone increased soil microbial biomass carbon (SMB-C) concentration (μg C g^?1 soil). Soil available C (C_ext) decreased significantly as compost maturity increased. For some composts (CSC), timothy yields matched those obtained with AN, and SOC gains were derived from both applied-C and increased crop residue-C returns to soil. A trend towards improved C returns across all treatments was apparent for the mixed crop. Matching composts of varying quality with the appropriate (legume/nonlegume) target crop will be critical to promoting soil C gains from compost use.     

Physical,Chemical and Biological Processes for Optimizing Decentralized Composting

On-site composting of nonpolluted organic wastes avoids costs and energy for transportation since the volume to be transported can be reduced to about 20% of the original. This paper describes the aerobic processes in a small-scale composting reactor, and evaluates how these processes can be optimized. The optimized composting process has a relatively short turnover time for organic matter; at the same time the temperature of about 60°C decreases the problems with pathogens and weeds in the mature compost. The compost produced has a high nutritional value, with high concentrations of especially nitrogen, potassium and phosphorus, while the contamination by heavy metals and other toxic substances are very low.     

Comparison of Analytical Methods for Organic Matter in Composts and Organic Mulches

Abstract

The conventional dichromate (Walkley and Black), carbon analyzer, and weight loss‐on‐ignition (WLOI) methods are compared for determination of organic matter contents in composts and organic mulches. The objective of this study was to evaluate these three methods for their reliability in determining the organic matter contents of composts and organic mulches that also contain inorganic carbon. The carbon analyzer method overestimated organic matter contents for samples containing inorganic carbon (C) as carbonate or charcoal C. The removal of inorganic C improved the correlation coefficients (r) of results obtained by the carbon analyzer method and the Walkley and Black method (0.95 vs. 0.89). The WLOI method produced results more similar to those obtained with the Walkley and Black method than with a carbon analyzer. Oven drying samples for 16–24 h at 105°C as a basal temperature for WLOI improved results compared with a basal temperature at 70°C, which is commonly used. A heating temperature of 500°C for 12 h resulted in organic matter determinations by the WLOI method in the closest agreement with those obtained by the Walkley and Black method.     

秋施有机肥对土壤生物学、理化性状及玉米产量的影响

以黑龙江省海林农场白浆土为研究对象,在等氮量条件下（秋季有机肥配施来年春季无机肥）,设置100%有机肥（T₁）,30%有机肥+70%无机肥（T₂）,20%有机肥+80%无机肥（T₃）,100%无机肥（T₄）和不施肥（CK）5个处理,研究长期施肥对土壤生物学、理化性状以及玉米产量的影响。结果表明:玉米生育期内,土壤微生物数量呈先升高后降低的变化趋势,且施用高量有机肥有助于细菌和放线菌群落结构的形成,无机肥和不施肥适于真菌生长;有机无机肥配施处理在提高土壤酶活性方面占据绝对优势,脲酶和蔗糖酶活性始终显著高于其他处理,且有机肥较无机肥处理更能提高玉米生育期内土壤微生物生物量;有机无机肥配施可明显提高土壤全量和速效养分,培肥地力,单施效果稍差,且差异不大,而高量有机肥在降低土壤容重、增加总孔隙度百分比方面作用显著;两年玉米累计产量30%有机肥（T₂）最高,分别比100%有机肥（T₁）和100%无机肥（T₄）提高57.34%和4.59%,稳产并高产。总体来讲,30%有机肥+70%无机肥为最佳施肥模式。     

Physical,Chemical, and Biological Changes in the Rhizosphere and Nutrient Availability

The rhizosphere is the soil zone adjacent to plant roots which is physically, chemically, and biologically different from bulk or non-rhizosphere soil. Adaptative mechanisms of plants influence physical (temperature, water availability, and structure), chemical [pH, redox potential, nutrient concentration, root exudates, aluminum (Al) detoxification and allelopathy], and biological properties (microbial association) in the rhizosphere. These changes affect nutrient solubility, transport, and uptake and ultimately plant growth. Major rhizosphere changes are synthesized and their influence on nutrient availability is discussed. In the last decade, significant progress has been made in understanding the rhizosphere environment and nutrient availability. However, the subject matter is very complex and more research is needed to understand the interaction between the plant, the rhizosphere environment, and nutrient availability.     

有机营养改土肥对河西内陆灌区玉米制种田理化性质和玉米经济性状及产量的影响

在甘肃河西内陆灌区玉米制种田,采用盆栽和田间试验,研究了有机营养改土肥与玉米制种田理化性质和玉米经济性状及产量间的关系。研究结果表明:影响玉米幼苗地上部分干重因素依次是聚乙烯醇Zn-SO4.7H2OCO(NH2)2(NH4)2HPO4糠醛渣,因素间最佳组合是:A2B3C3D1E2(糠醛渣1 500 g、CO(NH2)21 125 g(、NH4)2HPO4900 g、ZnSO4.7H2O 45 g、聚乙烯醇90 g)。随着有机营养改土肥用量的增加,玉米制种田孔隙度、团粒结构在增大,容重在降低。有机营养改土肥施用量与玉米制种田蓄水量、有机质、速效养分EC呈正相关,与pH呈负相关。有机营养改土肥施用量为0.06%时,可显著提高玉米幼苗植物学性状,施用量大于0.06%时,对玉米的植物学性状有抑制作用。随着有机营养改土肥施用量的增加,制种玉米经济性状、产量在增加,但单位(1 kg)有机营养改土肥的增产量则随施用量的增加而递减。经回归统计分析,有机营养改土肥最佳施用量为1 349.96 kg/hm2时,制种玉米的理论产量为7 080.00 kg/hm2。     

台湾有机农业的现况

有机农业之定义宽严界定因人而异,自完全自然放任的生态平衡农业耕作方式至不施用化学肥料及农业药剂或有限使用化学肥料与农业药剂的农耕方式。主要在倡导自然界物质之循环利用,维护生态,节省能源,减少污染,土地之永续利用,生产安全健康的农产品。可与宗教、生态保护、农药受害、地力维持、祈求安全食品者相结合发展。基于此种观点,在省中、南部设置相关试区,测试有机农法理念在台湾地区进行之可能性,包括利用轮作,间作,生物防治及微生物肥料于耕作中。综合目前试验成果显示,有机农耕法作物产量渐与惯行法相近,或略为增产。产品风味佳但     

香港有机农业发展

有机农业是利用天然再生资源配合环境和生态作用以生产高质量农产品和避免虫害的可持续农业生产方式。在20世纪80年代,有机农业由一些环保团体引入香港;在过去10年间,有机农业广泛引起社会的注意和兴趣。2000年香港政府推出（有机耕作转型计划）,目的主要是为香港农业创造新的生产模式,同时为市民提供多一个新鲜农产品的选择机会。首先介绍有机农业的一些重要概念和香港有机农业的发展过程,然后分析并评论有机耕作转型计划的成功和失败之处。     

Nuclear Magnetic Resonance,Infra-Red and Pyrolysis: Application of Spectroscopic Methodologies to Maturity Determination of Composts

Compost maturity or stability reflects the degree of decomposition of the organic matter (OM). Since stability of natural OM is a relative term, defining it is not a trivial challenge. In addition, it requires a series of chemical, physico-chemical and spectroscopic determinations. Among the methods applied, ¹³C-NMR and FTIR (or DRIFT) and pyrolysis have been shown to be of significance and therefore this review will be dedicated to studies focusing on the application of these methods to composting research. In fact, solid-state ¹³C-NMR spectroscopy has become the most important tool for examining the chemical structure of natural OM (NOM) and the chemical changes associated with OM decomposition. Changes can be measured on the bulk OM either fresh or composted, on humic substances (HS) extracted from the compost or on dissolved organic matter (DOM). Recently, 2D ¹H NMR has been employed to study properties of HS extracted from MSW compost. In general, changes measured on decomposing OM are more distinct in the following order of tested materials: DOM > Bulk OM > HS > Core HS. In conclusion, compost HS which are “young” relative to soil HS were shown to differ from the latter mostly in their high levels of aliphatic and polysaccharide components, which tend to decompose during composting. ¹³C-NMR is the most effective instrument applied to date to structural studies of NOM.     

Compost Maturity Assessment Using Calorimetry,Spectroscopy and Chemical Analysis

This work is aimed at characterizing compost maturity and, organic matter transformation during this process, by the use of nondestructive spectroscopic and thermal techniques, together with some chemical analysis. Composting was conducted in a laboratory over a period of one year using the organic fraction of domestic wastes, fresh farmyard manure, spent coffee and sawdust as the raw materials. Samples were retired after different periods of composting and were analyzed by differential scanning calorimetry (DSC) and fourier transform infrared (FTIR) spectroscopy as well as by routine chemical parameters including temperature, pH, C/N, ash content and humic-like substances content. Results showed that in case of domestic wastes, spent coffee and farmyard manure, the C/N ratios, ash and humic acid content showed a typical high rate of change during the first 197 days of composting and tended to stabilize thereafter, probably as a result of the maturity of the produced composts. In contrast, sawdust underwent only a very limited transformation even after one year of composting. Thermoanalytical and spectroscopic data confirms these finding and gives useful and complementary information with respect to the structure, the heterogeneity and the relative stability of the compost products. In particular, as the decomposition proceeded, there was an increase in aromatic to aliphatic structure ratio and a decrease in the importance of peptide structures of composts. Besides, both the spectroscopic and the thermal behavior of compost samples, retired beyond 197 days of composting, tended to be regular, less dependent on the raw material and close to that characterizing mature composts, with the exception of sawdust samples. We concluded that the spectroscopic and thermal techniques used are complementary to one another and to chemical tests and could be a powerful and fast approach for the study of compost maturity.     

Assessment of Seasonal and Site-Specific Variations in Soil Physical, Chemical and Biological Properties Around Opencast Coal Mines

Coal mining adversely affects soil quality around opencast mines. Therefore, a study was conducted in 2010 and 2011 to assess seasonal and site-specific variations in physical, chemical, and biological properties of soil collected at different distances from mining areas in the Jharia coalfield, India. Throughout the year, the soil in sites near coal mines had a significantly higher bulk density, temperature, electrical conductivity, and sulfate and heavy metal contents and a significantly lower water-holding capacity, porosity, moisture content, pH, and total nitrogen and available phosphorus contents, compared with the soil collected far from the mines. However, biological properties were site-specific and seasonal. Soil microbial biomass carbon (MBC) and nitrogen (MBN), MBC/MBN, and soil respiration were the highest during the rainy season and the lowest in summer, with the minimum values in the soil near coal mines. A soil quality index revealed a significant effect of heavy metal content on soil biological properties in the coal mining areas.     

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.     

稻草原位还田对双季稻田土壤理化与生物学性状的影响

于2010-2011年通过大田试验研究等量施肥条件下稻草不同原位还田方式(稻草全量还田、稻草烧灰还田和稻草不还田)对双季稻田土壤理化特性和生物学性状的影响.结果表明:稻草全量还田2年(4季)有利于改善土壤物理性状和提高耕作层土壤有机质、不同形态碳素、碱解氮、速效氮和缓效钾含量.土壤中3大类微生物总量以稻草还田处理大于稻草不还田和稻草烧灰还田,其土壤细菌、真菌的数量增加,而放线菌的数量减少;土壤蔗糖酶活性明显增加,而脲酶和过氧化氢酶活性变化不大.土壤脲酶活性与土壤全氮含量呈显著相关,蔗糖酶活性与有机质、全氮含量呈显著或极显著相关,过氧化氢酶活性与全氮、碱解氮和速效钾含量呈显著或极显著相关.     

生物炭与有机肥、无机肥配施对采煤塌陷区复垦土壤理化性状的影响

为了研究施用生物炭对采煤塌陷复垦土壤的熟化效果,以山西省晋城市采煤塌陷复垦区土壤为研究对象,连续3年采用生物炭与有机肥、无机肥配施等方式研究其对复垦土壤主要理化性状的影响。结果表明:不同施肥处理均不同程度改善了土壤的理化性状,有机肥配施生物炭处理明显降低了复垦土壤容重(降幅10%),提高了土壤孔隙含水率(增幅7.14%),但对土壤pH影响不明显。有机肥处理和无机肥处理的土壤全氮、全磷含量差异不显著;无机肥配施生物炭处理与单施无机肥处理相比,速效磷增加了8.33%,速效钾增加了6.34%,增幅较明显,对碱解氮影响则不明显。有机肥配施生物炭,土壤细菌、真菌、放线菌数量增幅不明显;无机肥配施生物炭,真菌数量增幅最为明显(11.7%)。有机肥、无机肥配施生物炭处理玉米产量分别提高了3.03%和2.70%,生物炭的增产作用有限。因此,在复垦土壤上施用生物炭后可以提高有机肥和无机肥的培肥效果,单施生物炭效果不明显。     

Carbohydrates as Chemical Constituents of Biowaste Composts and their Humic and Fulvic Acids

The decomposition of organic matter of source-separated biowaste during composting was followed during 18 months. Compost samples were fractionated into three parts: (i) hot water soluble extract (HWE) (ii) bitumen fraction and (iii) humic substances (humic acids (HA) and fulvic acids (FA)). Original compost samples and the HA and FA fractions were hydrolyzed with sulfuric acid for hexoses and pentoses. Quantitative spectrophotometric and qualitative GC/MS analyses of monosaccharides as trimethylsilyl ethers of the corresponding alditols were carried out.

During composting, the amount of HA in the organic matter of the compost increased, the amounts of HWE and bitumen decreased and the amount of the FA fraction changed only a little. Carbohydrates were found to be important constituents of biowaste composts and their HA and FA fractions. Elemental analysis (C, N and H) of compost and HA samples showed an increase in the C:H ratio and in unsaturation of compounds during composting. The decrease in the C:N ratio was marginal.

The amounts of hexoses and pentoses in original compost samples and the HA and FA fractions decreased during composting. The sugar alcohols erythritol, xylitol, L-arabitol, ribitol, L-rhamnitol, L-fucitol, D-mannitol, D-glucitol and galactitol were identified in both the HA and FA fractions. 2-Deoxy-D-erythro-pentitol was identified in one HA fraction and inositol in two FA fractions. An analysis of gas chromatographic data for relative abundances showed that, in every sample except one and in every stage of composting D-glucitol was the main sugar alcohol. In general, the relative amount of D-glucitol decreased during composting, while the relative amounts of all other sugar alcohols increased.

As chemical indicators of compost maturity, carbohydrates would appear to be a important group of compounds. Most informative as a general indicator would be the ratio of the amount of HA to the amount of organic matter in the total compost samples.

According to our studies, the carbohydrates in composts are covalently bound to the structures of FA and HA. Carbohydrate determination clearly deserves more attention in the structural elucidation of FA and HA.     

牧草的不同利用方式对果-草人工生态系统土壤理化及生物学性状的影响

采用单因素随机区组试验研究了果-草人工生态系统中牧草的不同利用方式对土壤理化及生物学性状的影响.结果表明;刈割覆盖、刈割压埋、畜肥还园3种利用方式均能较清耕提高土壤水分含量,降低土壤密度,稳恒土壤温度,提高土壤养分含量,增加土壤微生物数量,提高土壤酶活性.相关性分析发现,除全P与纤维分解菌、纤维分解酶、多酚氧化酶为负相关外,其余养分与生物因子间均呈正相关,且多数养分与生物因子呈显著或极显著相关;经通径分析发现,脲酶、硅酸盐细菌、纤维分解酶是促进有机质积存的主要生物因素,蔗糖酶是影响N、P、K速效养分的最主要因子,过氧化氢酶、多酚氧化酶、纤维分解菌只是选择性地对有机质的积存和N、P、K速效养分的形成起作用.     

Changes in Soil Properties and Vegetable Growth in Preparation for Organic Farming in Hawaii

Changes in soil properties and vegetable growth were quantified on a low-fertility tropical soil. Four treatments (two composts, urea, and control) were applied to an Oxisol (Rhodic Haplustox, Wahiawa series) in a field on Oahu, Hawaii. Chinese cabbage (Brassica rapa, Chinensis group) and eggplant (Solanum melongena) were grown sequentially as test crops. Soil quality as measured by hot-water-soluble carbon, dehydrogenase activity, and cation exchange capacity (CEC) increased by compost amendments. Total organic carbon or carbon dioxide (CO₂) respiration rate did not correlate with the soil amendments. Nitrogen (N) nutrition was the main factor that improved growth and carotenoid content in cabbage. The urea treatment promoted better growth in cabbage, whereas good-quality compost, made of grass clippings/tree trimmings, lime, and rock phosphate yielded better growth in eggplant, suggesting organic N requires time to mineralize and to be available to crops.     

Changes in Soil Physical,Chemical, and Biological Characteristics of a Temperate Desert Steppe under Different Grazing Regimes in Northern China

A field grazing experiment was conducted in Jingtai County, Gansu Province, China, from 2003 to 2010. The grazing intensity treatments included light grazing (LG, 0.45 sheep unit/ha), moderate grazing (MG, 0.75 sheep unit/ha), heavy grazing (HG, 1.50 sheep unit/ha), and no grazing (NG). Soil physical, chemical, and biological properties were measured. The results showed that, with increasing grazing intensities, the concentrations of total nitrogen, available nitrogen, organic matter, available phosphorus, available potassium, urease, catalase, and alkaline phosphatase in the soil decreased significantly with LG being mostly the greatest (P < 0.05). Soil bulk density for HG and NG was greater than that for LG and MG (P < 0.05). The concentrations of copper, manganese, and zinc were lower than their critical levels for plant growth, whereas iron was greater than its critical level. Correlation and principal component analyses revealed that soil trace elements were the secondary principal component compared with the primary elements, i.e., soil moisture, bulk density, etc.