不同处理对高含水率奶牛粪便好氧堆肥的影响

针对奶牛养殖场粪便含水率高,堆肥处理成本高的特点,采用以干燥玉米秸秆为调理剂,在较高初始含水率条件下（70%～80%）,进行了强制通风堆肥槽和翻转式堆肥仓的对比试验,并且探讨了晾晒脱水作为预处理对堆肥效果的影响。结果表明,各处理堆体升温迅速,且均在50℃以上维持8～12d,满足堆肥无害化的卫生标准（GB7959—1987）要求。至堆肥结束时,各处理含水率均降至40%以下,C/N均降至20以下,WSOC均低于16g·kg-1,NH4＋-N含量均低于0.4g·kg-1;除采用堆肥槽在初始含水率为65%下堆肥NH4＋-N/NO3--N〉3尚未腐熟完全外,其他处理NH4＋-N/NO3--N均小于0.5,腐熟情况较好;所有处理的GI均大于50%,其中采用堆肥槽在较高初始含水率堆肥和晾晒预处理后堆肥GI已达80%,基本消除了植物毒性。采用较为开放的堆肥槽时,以玉米秸秆作调理剂,在较高的初始含水率条件下堆肥效果更好;以晾晒脱水作为预处理后堆肥,可减少所需调理剂的用量,节约了堆肥的成本。     

The proportional mineralisation of microbial biomass and organic matter caused by air-drying and rewetting of a grassland soil

During the first few days after rewetting of an air-dried soil (AD-RW), microbial activity increases compared to that in the original moist soil, causing increased mineralisation (a flush) of soil organic carbon (C) and other nutrients. The AD-RW flush is believed to be derived from the enhanced mineralisation of both non-biomass soil organic matter (due to its physical release and enhanced availability) and microbial biomass killed during drying and rewetting. Our aim was to determine the effects of AD-RW on the mineralisation of soil organic matter and microbial biomass during and after repeated AD-RW cycles and to quantify their proportions in the CO₂-C flushes that resulted. To do this, a UK grassland soil was amended with ¹⁴C-labelled glucose to label the biomass and then given five AD-RW cycles, each followed by 7 d incubation at 25 °C and 50% water holding capacity. Each AD-RW cycle increased the amount of CO₂-C evolved (varying from 83 to 240 μg g⁻¹ soil), compared to the control with, overall, less CO₂-C being evolved as the number of AD-RW cycles increased. In the first cycle, the amount of biomass C decreased by 44% and microbial ATP by 70% while concentrations of extractable C nearly doubled. However, all rapidly recovered and within 1.3 d after rewetting, biomass C was 87% and ATP was 78% of the initial concentrations measured prior to air-drying. Similarly, by 2 d, extractable organic C had decreased to a similar concentration to the original. After the five AD-RW cycles, the amounts of total and ¹⁴C-labelled biomass C remaining in the soil accounted for 60 and 40% of those in the similarly incubated control soil, respectively. Soil biomass ATP concentrations following the first AD-RW cycle remained remarkably constant (ranging from about 10 to 14 μmol ATP g⁻¹ biomass C) and very similar to the concentration in the fresh soil prior to air-drying. We developed a simple mathematical procedure to estimate the proportion of CO₂-C derived from biomass C and non-biomass C during AD-RW. From it, we estimate that, over the five AD-RW cycles, about 60% of the CO₂-C evolved came from mineralisation of non-biomass organic C and the remainder from the biomass C itself.     

三种干燥方式对粪污厌氧残余物化学性质的影响

为揭示干燥方式对粪污厌氧残余物化学性质的影响,开展了真空冷冻干燥、风干干燥和热风干燥对粪污p H值、氨氮、总氮、含盐量、总有机碳和溶解性有机碳的影响,对客观认识粪污理化性质和粪污厌氧残余物干燥方式的优选提供依据。研究结果显示真空冷冻干燥处理方式各化学指标相比于风干干燥和热风干燥方式数值较大,表明真空冷冻干燥处理过程能够维持粪污厌氧残余物化学形态和较高的含量。在此基础上,比较发现真空预冻3 h和预冻6 h对各化学指标的影响差异不显著。建议真空冷冻干燥并且预冻3 h作为粪污厌氧残余物相对较适宜的干燥方式,不仅能够较少地破坏粪污化学性质,同时具有操作简便、节省时间等优点。     

Effect of Seed Drying on Germination Behavior and Seedling Growth of Sweetsop （Annona squamosa）

An experiment was conducted at the Department of Horticulture, College of Agriculture and Natural Resources, Kwame Nkrumah University of Science and Technology, Kumasi （KNUST） Ghana from September, 2009 to April, 2010, to determine the most appropriate drying method, as a post harvest practice, that would ensure high percentage germination ofAnnona squamosa seeds and its subsequent effect on seedling growth. The seeds were sun-dried, air-dried under shade or kept in the fresh state. Five treatments were used, namely, Freshly Sown seeds （Treatment 1, control）, Seeds Air-Dried under Shade for one day （Treatment 2）; Seeds Sun-Dried for one day （Treatment 3）; Seeds Air-Dried under Shade for three consecutive days （Treatment 4）; Seeds Sun-Dried for three consecutive days （Treatment 5）. The experiment was arranged in a Completely Randomized Design （CRD） and replicated three times. Drying of Annona squamosa seeds had significant effect on earliness and number of seeds germinated. Air drying under shade and sun-drying for three consecutive days improved earliness to germination （26 days after sowing） and percent total germination but air-drying under shade had better effect on total seed germination, achieving 90% germination in 42 days after sowing. Furthermore, the prevailing ambient temperature of 30 ℃-32 ℃ enhanced germination of Annona squamosa seeds. The study concluded that for optimum germination, seeds of Annona squamosa should be either air-dried or sun-dried for three consecutive days and be incubated in an ambient temperature range of 30 ℃-32 ℃. In terms of growth, seedling growth in leaf production was better from seeds sun-dried for three consecutive days.     

中式香肠自然晾挂成熟过程中微生物指标的变化规律

本研究对传统中式香肠自然晾挂成熟过程中的好氧菌总数、厌养菌总数、乳酸菌总数、嗜冷菌总数、酵母和霉菌总数变化规律进行测定和分析,为我国传统中式香肠技术水平的提升和工艺现代化研究提供理论参考与方法指导。     

晾晒对毛红椿苗木活力的影响

通过对毛红椿1年生苗木进行5种晾晒处理试验，测定不同晾晒处理时根系含水量、相对电导率、根系活力和栽植后的成活率，分析探讨毛红椿苗木水分与苗木活力的关系。结果表明：毛红椿苗木活力与其苗木水分密切相关，在晾晒的过程中苗木失水使相对含水量下降；相对电导率增加，根系活力下降，最终导致苗木成活率降低。所以在毛红椿造林时，要做好起苗后的苗木保护工作，尤其是根系的保护，这对于维持苗木活力、提高造林成活率有重要的意义。     

A comparison of different preservation methods for nitrogen isotopes of soil extractable NO3-

Nitrogen(N) isotope ratio(δ~(15)N) of soil extractable NO_3~- plays a pivotal role in the study of N biogeochemical circulation in ecosystems. However, the NO_3~-concentration and its isotope composition of soil samples are unstable, making sample storage critical for preserving the N isotope composition of extracted soil NO_3~-. Nevertheless, studies on the appropriate selection of storage methods after soil sampling are scarce. In this study, we compared two commonly used methods for storing soil samples and investigated the stability of N isotopes of soil NO_3~-. The results demonstrated that no significant changes in the NO_3~-concentration and δ~(15)N value occurred in the samples stored at-18?C. However, the soil NO_3~-concentration markedly increased, and NO_3~-δ~(15)N value significantly changed after air-drying storage. Meanwhile, we also found that NO_3~-and its δ~(15)N were well preserved in the filtered soil extracts after 1 month. In contrast, the NO_3~-concentration gradually decreased and the~(15)N in NO_3~-was gradually enriched in the bactericidal agent-containing soil mixture solution during the storage period. Overall, our results indicated that N isotopes of NO_3~-could be effectively preserved in frozen-stored soil samples or filtered soil extracts. For field investigations conducted in remote areas and continued for a long-time period(and lacking a refrigerant supply), soil extraction/filtration using a CaSO_4-saturated solution may be a superior preparation and storage method for analyzing N isotopes of soil NO_3~-.     

传统咸干鲅鱼自然风干过程风味物质变化

为探究传统水产加工制品咸干鲅鱼(Scomberomorus niphonius)的风味形成规律,对咸干鲅鱼自然风干不同阶段的水分含量、肌肉硬度值、游离氨基酸、呈味核苷酸以及挥发性成分进行了测定.结果表明,鲅鱼自然风干过程中水分含量逐渐减少,肌肉硬度值增大,逐渐形成肉质柔韧、富有嚼劲的特有口感.游离氨基酸总量在风干前期显...     

传统中式香肠自然晾挂成熟过程中生理生化特性及微生物的变化

对传统中式香肠自然晾挂成熟过程中的理化特性、生化特性和微生物的变化规律进行了测定和分析。结果表明,传统中式香肠自然晾挂成熟过程中的水分活度和水分均在干燥前16 d迅速下降,然后缓慢降低;pH则在干燥前12 d迅速下降,然后缓慢降低;蛋白质、脂肪和滴定酸度均在干燥前12 d迅速升高,然后缓慢上升;N aC l含量在整个干燥过程中一直显著上升;总糖虽然也一直呈上升趋势,但是不明显;色度在干燥前8 d迅速上升,然后快速下降;除非蛋白氮外,酸价、过氧化值、羰基价、硫代巴比妥酸值、氨基酸态氮、挥发性盐基氮均在整个干燥过程中呈上升趋势;好氧菌总数、厌氧菌总数、嗜冷菌总数、酵母和霉菌总数均在干燥前12 d呈上升趋势,然后迅速下降;乳酸菌总数在干燥前8 d呈上升趋势,然后迅速下降。     

晾制密度对雪茄烟主要含氮化合物变化规律的影响

为全面把握雪茄烟叶晾制过程中氮代谢产物的变化规律,以制定合理的调制工艺,以雪茄烟品种‘Gu-5’为试验材料,研究不同晾制密度（40、60和80 片·杆^-1）对雪茄烟叶主要含氮化合物变化规律的影响。结果表明,在各晾制密度下,烟叶各类含氮化合物变化趋势较为一致。其中,总氮含量变化呈“双峰曲线”,晾制结束时含量最低;可溶性蛋白降解主要发生在萎焉期和变黄期,氨基酸积累与蛋白质降解同时进行,呈“快-慢-快”的变化规律;总生物碱含量小幅度降低;硝酸盐含量在晾制前后变化不大。不同晾制密度相比,40片·杆^-1处理下烟叶总氮、蛋白质和生物碱降解最快,3种化学成分均在晾制第25 d达到最低值;同时,该处理烟叶中氨基酸在晾制过程中得以充分积累,最终达到7.61 mg·g^-1;此外,其硝酸盐含量则始终最低。综合来看,40 片·杆^-1的晾制密度更有利于改善雪茄烟叶的品质和工业可用性。