有机固体废弃物堆肥的腐熟度评价指标

有机固体废弃物堆肥的腐熟度指标是评价堆肥稳定及安全农用的重要参数，通过综述堆肥的物理、化学、生物学指标，提出评价堆肥的腐熟度时，物理指标一般作为辅助指标，化学指标中T值≤0．6、水溶性C／总有机N≤0．70可以稳定应用，核磁共振和红外光谱分析可以精细地评价腐熟后堆肥产品中各组分，发芽率指标可作为堆肥产品安全稳定的生物指标。在应用时要与BOD、CEC、腐殖化参数等多方面结合来评价堆肥的腐熟程度。     

鸡粪堆肥腐熟度参数及波谱的形状研究

本研究从农业固体废弃物资源化利用角度出发,设计了以鸡粪、玉米秸秆为原料和填充料的高温堆肥体系,应用物理分析法、化学分析法、波谱分析法和植物生长分析法研究了高温堆肥的腐熟度参数及指标。结果表明,温度是表征高温堆肥腐熟度的最直接参数。随着堆肥进程的进行,C/N、NH4+-N含量呈下降趋势,HA/FA呈上升趋势,它们能较好地反映高温堆肥腐熟程度,可以作为堆肥的腐熟指标。堆肥胡敏酸可见光谱、红外光谱、核磁共振光谱对堆肥有机质结构变化和腐熟度判定具有重要的参考价值;堆肥过程中堆肥腐熟指标变化与种子发芽率变化规律具有一定的相关性。     

堆肥含水量与腐熟度对其粉碎度的影响研究

以鸡粪和麦秸为原料，通过堆肥不同腐熟度和不同含水量下粉碎度的测定，表明堆肥含水量是控制粉碎度大小的首要因素，堆肥粉碎度随含水量的增加而降低，两者满足二级动力学方程。粉碎度的临界含水量为20％，含水量低于20％时，粉碎度的变化较小。含水量大于20％时，腐熟度对粉碎度的影响增强。腐熟的堆肥更容易粉碎。粉碎度与GI(发芽指数)、EC、pH值等腐熟度指标并不存在相关关系。但与TOC呈负线性相关，与全N、C/N比呈显著负二次相关。粉碎度与堆肥化学参数：纤维素、半纤维素含量呈负线性相关，与木质素无相关性。     

畜禽粪便堆肥腐熟度评价指标体系研究

以牛粪和猪粪两种畜禽粪便分别与秸秆混合堆肥,全面考察了堆肥过程中与腐熟度有关的理化指标和生物指标变化。结果表明,在3个月的堆肥熟化试验考察期内,堆肥初期堆体升温迅速,50℃以上高温持续时间累计超过15d;物料pH值先升后降,60d后稳定在8.0左右;含水率和C/N持续下降,C/N60d后接近20;氨氮含量呈先升后降趋势,胡敏酸和富里酸比值则先降后升;Solvita腐熟等级、种子发芽势和根系建成指标不断升高,而作物生长指标则无显著变化。由腐熟度指标相关性分析表明,最能体现堆肥腐熟程度的Solvita腐熟等级与C/N、种子发芽势、根系建成指标呈高度相关,与含水率和腐殖酸呈低度相关。据此,结合常规温度指标建立了堆肥腐熟度评价指标体系,用于科学指导农牧业废弃物堆肥质量控制。     

北京南宫静态堆肥隧道仓不同区间的垃圾堆肥腐熟度模糊评价

以南宫堆肥厂27 m长的静态高温堆肥发酵隧道仓为研究对象，对其10个不同区间的垃圾堆肥腐熟度进行分析并进行了模糊评价。结果表明：经过14d的高温静态发酵，10个区间的垃圾堆肥物理组分均发生了明显变化；垃圾堆肥含水率均未达到一次发酵结束时的要求；从电导率、pH值、E₄/E₆、固相C/N、GI等指标来看，10个区间的垃圾堆肥均达到了基本腐熟。模糊评价结果表明：南宫堆肥厂的堆肥隧道仓中，各区间垃圾堆肥的腐熟程度并不一致：隧道仓第6区间(13.5～16.2 m)的垃圾堆肥腐熟程度最好；第1区间(0～2.7 m)、第9区间(21.6～24.3 m)、第10区间(24.3～27 m)垃圾堆肥腐熟程度最差；其他区间的垃圾堆肥腐熟度居中。     

不同腐熟度猪粪、奶牛粪在小白菜和香瓜上施用的农学效应研究

进行猪粪和奶牛粪自然高温堆肥发酵,分别在15、25、35、50 d取样,获得了不同腐熟程度堆肥产物,分别进行了小白菜和香瓜种子发芽与田间应用试验,以期获得不同腐熟堆肥在蔬菜上施用的农学效应,旨在从堆肥农田施用的农学效应角度,为制订堆肥腐熟度标准提供科学依据。结果表明:牛粪堆肥过程中的最高温度高于猪粪,且高温期也长于猪粪;两种处理在35d有机碳含量均显著降低,全氮含量为先降低后升高趋势;两种堆肥在35d后,均达到无害化标准。不同腐熟程度堆肥对小白菜株高和主根长及香瓜苗重和主根长均没有明显抑制作用,对小白菜和香瓜出苗率、根系活力及小白菜单株鲜重和生物产量影响较大,尤其是猪粪腐熟25d,奶牛粪腐熟15d的堆肥表现出显著抑制作用。将堆肥理化参数与小白菜、香瓜生长指标进行相关分析表明:pH值、全氮含量和C/N这3种指标均与小白菜和香瓜各项生物性状无显著相关性;有机碳和DOC与各项生物性状指标均表现出显著或极显著相关性;铵/硝与小白菜和香瓜的GI和根系活力均表现极显著或显著的相关性,其结果与现行的堆肥腐熟度指标并不一致。因此,在制订堆肥腐熟度标准时,应关注堆肥产物农田施用后不同作物所表现出的不同农学效应。     

基于机器学习的畜禽粪便资源化预测研究

为了比较不同来源的畜禽粪便理化性质差异,考察堆肥过程中与腐熟度有关的理化指标变化情况,采集5种畜禽粪便的原料(堆肥原样)和堆肥腐熟后的样品,对其进行性质测定分析;同时,为探索预测堆肥腐熟度的最优模型,选用XGBoost、随机森林、支持向量机(SVM)、多元非线性回归模型对训练集样本堆肥腐熟度进行预测,并利用测试集样本对比分析4种模型的预测精度。结果表明:羊粪、牛粪、猪粪、兔粪、鸡粪原样均为弱碱性,其浸提液中可溶性盐浓度(EC)较高,鸡粪原样总养分(N、P、K)含量最高,猪粪原样中金属元素铜、锌、铁、锰总含量和有机质含量最高;5种粪便原样经过升温腐熟过程后,铜、锌、铁、锰元素含量和发芽率均表现出明显的上升趋势,pH值、EC值和有机质含量呈显著下降趋势;堆肥有机质含量和含水率对堆肥腐熟度影响最大,%IncMSE值分别为14.92%和13.61%;通过构建XGBoost、随机森林、SVM机器学习模型和多元非线性回归模型,经特征选择模型优化后,仅选取含水率和有机质含量作为特征变量,即可准确地预测堆肥腐熟度,模型预测值与实测值间的拟合优度(R2)分别为0.994、0.871、0.908、0.800。其中,XGBoost模型表现出较高的预测性能,均方根误差和平均绝对误差分别为4.690%和4.042%。相比于模型优化前,XGBoost、随机森林、SVM的R2分别升高41.39%、5.83%和36.30%。由于堆肥腐熟前后pH值、含水率、有机质及发芽率变化显著,且与其他性质之间存在较高的相关性,据此选取其作为堆肥腐熟度的评价指标。综合分析结果认为,XGBoost模型对堆肥腐熟度的预测精度最高,特征选择是提高模型预测精度的有效方法。     

堆肥过程中水溶性有机物的SUVA_(254)、SUVA_(280)值的变化及其与腐熟度进程的关系

在有机肥堆制过程中找到一个简单、灵活、准确和易于接受的判定腐熟程度的标准是研究者一直追寻的目标。本研究以鸡粪和稻壳作为原材料堆肥,研究堆腐过程中堆肥水溶性有机物(DOM)的SUVA_(254)和SUVA_(280)紫外光谱特征值的变化,对比传统的几种判定堆肥腐熟度的方法,对SUVA_(254)和SUVA_(280)值与堆肥腐熟度关系进行了量化研究。结果表明,按堆制过程中C/N判断,SUVA_(254)和SUVA_(280)的值分别为0.247和0.180时堆肥达到腐熟;按种子发芽指数(GI)判断,SUVA_(254)和SUVA_(280)值分别为0.192和0.153时堆肥基本腐熟,SUVA_(254)和SUVA_(280)值分别为0.247和0.180时堆肥完全腐熟。本研究结果可为判断堆肥腐熟度提供一个较为简便快捷的方法和新思路。     

堆肥种子发芽指数测定方法与敏感性种子筛选

种子发芽指数（Germination Index,GI）作为评价堆肥腐熟度的权威指标,被广泛应用于评价堆肥产品植物毒性等方面,但对于GI测定方法和供试种子类型仍缺少统一标准,导致不同堆肥研究的GI结果缺乏可比性。为此,该研究通过设置不同毒性梯度的堆肥试验、选取不同类型种子,详细介绍了GI测定方法,规定根长为0 mm和1 mm的计量标准以及根长起始测量位置,并系统分析了表征堆肥腐熟度指标与种子发芽之间响应关系。结果表明：最终产品GI以纯猪粪（26.54%～80.49%）、纯羊粪（16.71%～92.98%）、猪粪+秸秆（28.28%～110.74%）、羊粪+秸秆（43.38%～119.69%）的顺序递增。综合分析不同堆肥处理理化指标（温度、氧气、pH值、碳氮比）和植物毒性因子（电导率、铵根、有机酸和有机质）与不同种子GI（黄瓜、萝卜、白菜、油菜）相关性关系,发现萝卜种子响应度最高（3.69,r=0.96）,在综合表征堆肥腐熟度和植物毒性上最具科学性和代表性。以上结果可为种子发芽指数测定、有机肥标准制定以及堆肥农田安全施用提供参考。     

堆高对生活垃圾中15 mm筛下物堆肥腐熟的影响

为了解小粒径生活垃圾的独立堆肥适宜性,并筛选最佳堆高,本文以北京市马家楼垃圾转运站筛分后的0～15 mm生活垃圾为研究对象,在南宫堆肥厂隧道发酵仓分别以2.5、2.0、1.5和1.0 m 4个堆高进行强制通风条件下密闭静态高温发酵对比试验。通过高温发酵（8 d）前后采样测定堆肥水浸提液的电导率（EC）、腐殖酸光学特性（E4/E6）、水溶性碳（WSC）质量分数、水溶性铵态氮（NH4+-N）质量分数和发芽率指数（GI）,堆肥固相碳氮比（C/N）和粪大肠菌值等腐熟度指标,并应用模糊评价法进行腐熟度评价。结果表明：0～15 mm粒径的生活垃圾可单独堆肥,且1.5和1.0 m 的2个堆体的腐熟程度最好,综合考虑后推荐在隧道发酵仓中采用1.5 m为最适宜堆高。     

低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响

【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。     

Biodiversity and ecogeography of wild Lactuca spp. in some European countries

Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.     

Pasture Vegetation Elemental Analysis by Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.     

Properties of anaerobically digested and composted municipal solid waste assessed by linking soil mesofauna dynamics and nitrogen modelling

We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass, soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration, N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially (<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils, indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea.     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.