蚯蚓粉的营养成分分析及贮藏性评价

研究了自制蚯蚓粉的营养成分和不同温湿度条件下的贮藏稳定性.结果表明,蚯蚓粉的蛋白质含量高,达到69.52％.共检出16种氨基酸,必需氨基酸/总氨基酸值为36.4％,必需氨基酸/非必需氨基酸值为61.62％,符合蛋白质理想模式.蚯蚓粉贮藏28 d后,酸价随时间的延长而升高,温度越高,水分和湿度越大,酸价升高越快.在20、30℃和湿度50％条件下,样品在贮藏28 d后的酸价为3.61～5.84 mg/g;过氧化值均呈现贮藏初期先下降随后上升的趋势;蚯蚓粉在所设条件下贮藏28 d后,胃蛋白酶消化率没有发生明显变化,均在88％以上,符合饲用鱼粉一级品86％的国家标准.在试验温度和湿度范围内贮藏28 d后,蚯蚓粉仍保持较好的品质,表明蚯蚓粉可作为优质的饲料蛋白.     

接种蚯蚓对桉树根系生长的影响

为了研究桉树人工林接种蚯蚓对桉树根系的生长效应,采用单因素随机区组试验对桉树下不同基质接种蚯蚓后,桉树根系生长量、根系活力、根系构成情况进行研究和统计分析。结果表明：接种蚯蚓对桉树根系生长量、根系结构和根系活力产生显著影响。与对照相比,牛粪基质和桉树叶基质接种蚯蚓处理,小于1mm根级新根比例分别提高10．08％、9．12％;诱导出的桉树新根其干重与鲜重之比分别提高21．86％、13．38％;根系活力分别提高147．73％、127．19％。牛粪和桉树叶作为基质接种蚯蚓,均能诱导桉树新根的产生,促进根系的生长。     

Effects of organic versus conventional arable farming on soil structure and organic matter dynamics in a marine loam in the Netherlands

Abstract. We compared the effects of conventional and organic arable farming on soil organic matter (SOM) content, soil structure, aggregate stability and C and N mineralization, which are considered important factors in defining sustainable land management. Within one soil series, three different farming systems were selected, including a conventional and an organic arable system and permanent pasture without tillage. The old pasture represents optimal conditions in terms of soil structure and organic matter inputs and is characterized by high earthworm activity. More than 70 years of different management has caused significant differences in soil properties. SOM content, mineralization, earthworm activity and water-stable aggregation decreased as a result of tillage and arable cropping when compared with pasture, but were significantly greater under organic farming than under conventional farming. Total SOM contents between 0 and 20 cm depth amounted to 15, 24 and 46 g kg⁻¹ for the conventional arable, organic arable and permanent pasture fields, respectively. Although less sensitive to slaking than the conventionally managed field, the soil under organic farming was susceptible to compaction when high pressures were exerted on the soil under wet conditions. The beneficial effects of organic farming are generally associated with soil biochemical properties, but soil physical aspects should also be considered. Depending on soil type and climate, organic farmers need to be careful not to destroy the soil structure, so that they can enjoy maximum advantage from their organic farming systems.     

全灭菌环境下蚯蚓和堆肥对土壤五氯酚老化过程的影响

通过全灭菌环境下的土壤五氯酚（PCP）污染模拟实验,分别测定水提取态、乙醇提取态、腐殖质固定态以及蚯蚓生物累积态PCP的变化,研究添加两种不同蚯蚓品种（赤子爱胜蚓和壮尾环毛蚓）和堆肥对土壤PCP老化过程的影响。结果显示,在42d的培养期内,水提取态PCP在全灭菌土壤对照和添加灭菌堆肥的处理中随时间推移逐渐下降,存在明显的老化效应。在蚯蚓处理中,水提取态PCP呈现先下降后上升的趋势,说明蚯蚓促进土壤PCP的解吸附,这主要与蚯蚓的生物扰动作用以及调节土壤pH趋向中性的作用直接相关。培养结束时,蚯蚓能够有效促进土壤PCP向腐殖质固定态转化,并进一步促进PCP的去除,这与蚯蚓提高土壤腐殖质的含量,促进PCP的化学还原转化作用以及蚯蚓自身对PCP的消解作用有关。壮尾环毛蚓比赤子爱胜蚓更能有效促进PCP的转化与去除,这与两者的生活习性不同有关。灭菌堆肥对全灭菌土壤PCP向其他形态转化的影响不显著。     

蚯蚓在牛粪转化过程中的作用

鉴于牛粪对环境造成的污染,本文主要介绍了牛粪的蚯蚓处理方法。着重介绍了蚯蚓品种选择、生活习性、养殖方法、生长繁殖、饲养管理、收集等方面的技术,并对蚯蚓粪的特点进行了介绍。     

Assessing significant harm to terrestrial ecosystems from contaminated land

Abstract. Terrestrial ecosystem risk assessment remains in its infancy by comparison with the aquatic discipline, yet it is advancing quickly in response to increasing concerns surrounding soil quality and the sustainable use of soil. Several international frameworks have been developed during the last decade to aid decision-makers as the need for scientifically derived tools for determining ecological risk from land contamination has been recognized. From the regulatory viewpoint, the priority is establishing what to protect in order to prevent ecological harm. This is a complex issue requiring clear objectives in a risk assessment context. The most important factor in assessing ecological harm is whether or not ecosystem function is altered as a result of land contamination and, if it is, judging the significance. A consensus is developing that ecological risk assessment should aim to protect populations rather than individuals. This paper critically reviews recent developments in risk assessment for terrestrial ecosystems and land contamination in the UK, with emphasis on deriving a measure of ecological harm to assess ecosystem function. We seek to further justify the use of earthworms as a favoured indicator species for protecting ecological function. Guidance on how to measure harm in relation to ecological function is, however, still lacking.     

Study of cadmium (Cd)-induced oxidative stress in Eisenia fetida based on mathematical modelling

As a sensitive biological indicator, earthworms are widely used to monitor various pollutants of soil and provide an early warning for soil pollution. However, because many indices are involved in the exposure-induced oxidative stress response, practical applications of these indices are quite inconvenient. Therefore, it is appropriate to investigate the key monitoring index for use in early warning and pollution monitoring. Using Eisenia fetida as an experimental model in an indoor simulation experiment, the mathematical modelling of the effect on oxidative stress in earthworms under cadmium (Cd) stress was studied. The test lasted 40 d, with the removal of one earthworm every 10 d. The Cd²⁺ concentration gradient was set as 0, 1, 10, 20, 100, 200, 400, and 800 mg kg^-1 dry weight. The earthworms were divided into two sections from the clitellum for the determination of total protein (TP) and peroxidase (POD), superoxide dismutase (SOD), glutathione-S-transferase (GST), glutathione peroxidase (GPX), catalase (CAT), malondialdehyde (MDA), and acetylcholinesterase (AChE) activities. Results showed that POD was the key index of oxidative stress in head tissues after 10 d of exposure, TP was the key index at 20 d, and POD became the key index again at 30 and 40 d. By contrast, in tail tissues, MDA and SOD were the key indices at an exposure time of 10 d, GPX at 20 d, CAT and TP at 30 d, and POD and MDA at 40 d. These results contribute to establishing a scientific method for ecotoxicological diagnosis and revealing the mechanism of soil Cd toxicity.     

Behavior and respiration responses of the earthworm Eisenia fetida to soil arsenite pollution

Soil arsenic (As) pollution from mining and industrial sources is a serious issue in China. Earthworms are considered ecosystem engineers and contribute to soil fertility development and maintenance of soil physico-chemical properties. In this study, earthworms were exposed to soils with different sodium arsenite concentrations (0, 5, 20, and 80 mg As kg^-1) for 60 d to investigate the changes in soil properties and the responses of the earthworms (e.g., burrowing activity and respiration). Earthworm burrowing activity decreased with increasing arsenite concentrations, and earthworm respiration was significantly lower in soils with 20 and 80 mg As kg^-1 compared to 0 mg As kg^-1. Changes in soil properties were also observed after incubation of As-amended soil with earthworms. Specifically, soil pH decreased, while soil electrical conductivity and contents of soil NH₃^--N, Olsen-P, and available K increased. Our results suggest that arsenite negatively impacts the metabolic activity of earthworms, leading to reduced burrowing activity, which in turn modifies the effects of earthworms on soil fertility and remediation.     

Earthworm populations are stable in temperate agricultural soils receiving wood-based biochar

The application of decomposable organic residues such as manure and crop litter is generally beneficial to earthworms. There is an emerging interest in applying biochar, a carbonaceous product of pyrolysis, to temperate agricultural soils. The slow decomposition rate of biochar, which also contains ash and combustion byproducts, could be detrimental to earthworms. The objective of this study was to describe the earthworm populations in biochar-amended soils on a dairy farm in the St. Francis River watershed, Quebec, Canada. Earthworms were collected from replicated field plots under cereal production. Site A received three wood-based biochar types at two application rates(5 and 10 t ha~(-1) biochar) plus an unamended control, while Site B received wood-based biochar(7.5 t ha~(-1) biochar), dairy cattle slurry(10 t ha~(-1) manure), or a combination of the biochar and manure rates plus an unamended control. Earthworms were collected by hand sorting and formaldehyde expulsion from soil pits. Three species, Aporrectodea turgida, Aporrectodea tuberculata, and Lumbricus rubellus, were found at the sites, and Aporrectodea was the dominant genus. Biochar sources, rates, and application with dairy slurry did not affect the earthworm population, which had 52–218 individuals m~(-2) in 2010 and 4–96 individuals m~(-2) in 2011. The seasonal variation in earthworm population may be due to flooding in the spring of 2011, which apparently interfered with earthworm reproduction. The similarity in earthworm abundance and biomass in plots with and without wood-based biochar leads to the conclusion that earthworm populations are stable in biochar-amended soils in this cold, humid temperate region.