Microbial activity and biomass in mixture treatments of soil and biogenic municipal refuse compost

An incubation experiment was performed to determine how the mixing of soil with municipal organic refuse compost affects C mineralization, growth of the microbial biomass, and changes in organic components, especially in the fractions of amino acids and amino sugars. Compost and soil differed in almost every parameter measured, with the organic C content of the compost representing only 10.8% of the dry weight. The fractions of K₂SO₄-extractable organic C and of non-hydrolyzable C were larger in the compost (1.24 and 62.9% of organic C, respectively) than in the soil (0.56 and 41.6% of organic C). These two fractions increased in proportion to the addition of compost, in contrast to amino sugar and amino acid C which were identified overproportionately in the mixture treatments, especially in the 30% compost treatment. Overproportionate increases in the microbial biomass C content and CO₂ evolution rate were also measured in this treatment. The adsorption of compost colloids on the surface of regular soil silicates increased both the availability for microbial enzymes and the detectability for chemical analysis.     

Physico-chemical properties of commercial composts varying in their source materials and country of origin

Composting is a partially controlled bio-oxidative process through which highly heterogeneous organic matter (OM) in its solid-state transforms into a humified material. The variability of the OM undergoing composting makes compost research a great challenge. Our purpose was to define chemical and plant response characteristics of a variety of composts, grouped based on their major source materials. Thirty-seven commercial composts were collected from France, Greece and the Netherlands. When grouped by country of origin, significant differences were found in %OM, %C, %N, dissolved organic carbon (DOC) concentration, electrical conductivity (EC) and NO₃ concentration. These differences may be attributable to source materials or local regulations and quality control measures. When the composts were classified into 7 groups by their source materials: wood, green, manure, grape marc (GM), oilcake, spent mushroom substrate and municipal solid waste-based composts, significant differences between groups were found in %OM, %C, %N, DOC, pH, EC, NO₃ and soluble sugars. Extracts of composts from all groups, except GM and oilcake had absorbance in the UV and visible range that was linearly correlated with DOC. GM and oilcake compost extracts had lower absorbances and distinctly lower specific UV absorbance (SUVA). Diffuse reflectance infrared Fourier Transform (DRIFT) spectra of the composts from different source groups also exhibited distinct group features (e.g. the ratio of polysaccharide to aliphatic peak intensity), whereas NMR spectra did not. Cucumber plants grown on manure-based composts had greater fresh weight than those grown on other composts. Plants grown on oilcake and GM composts exhibited low fresh weight. The difference in characteristics of the oilcake and GM composts may be a result of their unique chemical composition which slows their degradation. It may also be related to their relatively low degree of maturity, which is a consequence of their slow degradation.     

Effect of the addition of municipal solid-waste compost on microbial biomass and enzyme activities in soil

Summary Changes in the content of C, N, P, and S in the soil biomass and in phosphatase, urease, protease, deaminase, and arylsulphatase activity, induced by amendment with municipal solid-waste compost, were determined in a clay loam soil during 1 year of incubation at 25° and 35°C.In the unenriched soil (control) decreasing trends in biomass C, biomass N, and biomass S were observed at both temperatures. In the enriched soil, these values increased, reaching a maximum after 1 month. Biomass P, probably due to a slower process of P immobilization, showed different trends. Alkaline phosphomonoesterase, phosphodiesterase, and deaminase activity remained constant after reaching maximum values (3–5 months). Arylsulphatase, urease, and protease activity tended to return to baseline after reaching a maximum (2–3 months).Atrazine, though applied at a dose that was 10 times higher than the recommended field rate, did not modify the chemical and biochemical properties of either the control or the enriched soil.Significant positive and negative correlations between changes in biomass values and changes in enzyme activity were found. The negative correlations are attributed to the delay in the enzymatic response compared with the changes in microbial biomass.     

发达国家畜禽废物处理技术与立法

源于集约化畜禽养殖场的大量粪便及废水导致的环境污染问题越来越受到人们的关注,发达国家十分重视畜禽废物的处理技术研究及控制由其引起污染的立法工作。该文在分析畜禽废物管理系统的构成、约束及目标基础上,对发达国家近年来处理技术的发展进行综述,包括还田利用、好氧与厌氧生物处理、存贮、收集与运输、提取新产品及优化模型与决策支持系统等方面,最后对有关畜禽废物管理方面的法规做了介绍。     

Nitrogen mineralization from mature bio‐waste compost in vineyard soils. I. Long‐term laboratory incubation experiments

The steadily increasing utilization of bio‐waste compost in German viticulture requires a more detailed investigation of nitrogen (N) mineralization parameters for mature bio‐waste compost applied to vineyard soils. N mineralization kinetics were described with two superposing exponential equations. Long‐term aerobic laboratory incubation experiments of 12 soil‐compost substrates revealed that 5±2.8% of its total N content could be released from a rapidly decomposable fraction (half‐life period t₅₀ = 41 d at 15°C) and another 60±2.9% from a slower decomposable fraction (t₅₀ = 490 d). The remaining proportion (35%) is considered not to be released in the medium term. The obtained potentially mineralizable nitrogen of 65% of total compost N significantly differs from current fertilizer recommendations, which were adopted from calculations for agricultural conditions. For fertilizer recommendations in viticulture, we recommend the consideration of a higher N‐mineralization potential for organic fertilizers.     

中国矿业用地现状分析

当前中国矿业用地存在土地使用权取得方式单一、使用粗放，开采占地方式多、占用数量大，各类占用破坏严重，重开发生产、不注重保护治理，矿山开采企业经营困难、难以落实复垦政策等五大特征。文中提出了解决矿山用地问题的途径，提出拓宽供地方式、建立专门复垦管理机构、专门基金、多方承担复垦工程任务和加强执法力度等。     

垃圾堆肥对难溶性磷转化及土壤磷素吸附特性影响

在城市生活垃圾进行工厂化堆肥过程中，加入难溶性磷矿粉，探讨堆肥对难溶性磷的转化能力及堆肥产品培肥后对土壤磷素吸附特性的影响。结果表明，加入磷矿粉可使堆肥中活性有机磷、中等活性有机磷、中稳性有机磷、高稳性有机磷及速效磷含量均有不同程度的提高，与对照相比分别增加212.69%、80.36%、61.21%、62.74%、157.89%。通过电镜观察表明，堆肥后磷矿粉典型的矿物特征消失，表面呈蜂窝状。将堆肥后的产品进行培肥试验表明，富磷垃圾肥处理可明显改善土壤磷素的吸附特性，与施化肥相比，最大吸附量(Q_m)下降8.76%，最大缓冲容量(Q_m·K)下降13.58%，而磷素的吸附饱和度(DPS)、零净吸附浓度磷(EPC₀)则呈不同程度的增加，幅度依次为98.52%、7.13%。试验结果显示，通过堆肥生产富磷垃圾肥可为解决中国磷素资源缺乏、化学磷肥利用率低等问题提供一条生物学途径。     

城市生活垃圾堆肥过程中腐熟度指标及控制参数

以日处理400 t经马家楼筛分处理后的15～60 mm生活垃圾的北京南宫堆肥厂垃圾堆肥过程为研究对象，对堆肥过程中垃圾的理化性质、腐熟度指标与控制参数进行了研究。结果表明，堆肥过程中水分含量是下降的；不同季节堆肥pH值的总体变化均呈上升趋势；电导率(EC)降到了作物受抑制的限定值以下，不会对作物产生盐分毒害；堆肥水浸提的腐殖酸E₄/E₆值随着垃圾堆肥腐熟度升高呈增加趋势；24 h和96 h的发芽率指数(GI)表明垃圾堆肥时间可以从8周缩短到5周；有机碳、总氮和C/N比随着堆肥时间的增加均呈下降趋势；C/N比与E₄/E₆值和GI(24 h和96 h)值呈显著负相关关系，EC值与E₄/E₆值和GI(24 h和96 h)值呈极显著负相关，而E₄/E₆值与GI(24 h和96 h)值呈极显著正相关。