冬季侧窗通风猪舍氨气和温室气体排放特征

冬季猪舍通风管理方式影响猪舍内的环境质量以及污染物的排放,为确定改造后猪舍侧窗负压通风系统6阶段管理对冬季舍内环境质量以及氨气和温室气体排放的影响,对舍内温度、湿度和空气流速等环境指标进行了测定,采用水分平衡方程确定了不同通风阶段猪舍的通风率,利用INNOVA 1412多气体分析仪-连续采样测试技术,对冬季猪舍NH_3、N_2O、CH_4和CO_2的排放进行了测定,确定了不同通风量条件下氨气和温室气体的排放率。结果表明,冬季侧窗通风密闭式育肥猪舍平均温度为13.7℃,湿度为69.7%,舍内最大温度与湿度差值分别为3.2℃和39.6%,平均通风率为6 207 m~3·h~(-1)(单头生猪通风量:24.9 m~3·h~(-1)),舍内平均空气流速为0.28 m·s~(-1),满足了育肥猪生长的要求;冬季试验猪舍中NH_3平均浓度范围在8.42～15.63 mg·m~(-3),CO_2平均浓度范围保持在2 509～5 303 mg·m~(-3)之间,CH_4浓度变化在1.11～5.90 mg·m~(-3),可满足冬季育肥猪生长的需求;单头生猪NH_3、CO_2和CH_4的平均排放率分别为250.0 mg·h~(-1)、79.9 g·h~(-1)、57.7 mg·h~(-1),单头生猪累积日排放量分别为6.0 g·d~(-1)、1.92 kg·d~(-1)和1.39 g·d~(-1),试验期间没有监测到N_2O的排放;采用的6级通风管理模式显著影响NH_3、CO_2的平均排放率,对CH_4的排放影响不显著。     

草原能源工程学刍议

作者概述了目前草原上能源的使用情况,列举了适合草原特点的能源种类及几种能源资源的分布,对几种主要能源的应用前景及目前在应用中存在的问题作了探讨。     

温带森林中风倒形成的坑和丘对土壤性质和温室气体排放的影响

Pit and mound micro-relief(resultant microsites from trees uprooted by windthrow) could have regimes of microclimate and soil features that differ from areas of undisturbed soil. In an attempt to provide a comprehensive evaluation of the significance of pits and mounds on soil features and also the dynamics of greenhouse gas(GHG) fluxes at local scale, this study was carried out in a reserved area of Darabkola forest in Mazandaran Province, northern Iran. The age of a pit and mound was considered equal to the degree of decay of the blown down tree. Three microsites were distinguished, consisting of pit bottom(PB), mound top(MT) and undisturbed area(UA). Soil samples were taken at 0–15 and 15–30 cm depths from all microsites and analysed for soil physical, chemical and biological features. Our findings suggested that in context of forest ecology, pits and mounds following windthrow events should be considered as an effective factor influencing soil features(i.e., density, texture, water content, p H, organic C, total N, available nutrients and earthworm density/biomass) and especially GHG fluxes. Results showed that MT acted as a sink for N2O(-0.010 mg N2 O m-2d-1) and CH4(-0.257 mg CH4m-2d-1) fluxes and also produced lower CO2 concentrations(0.095 mg CO2 m-2d-1) than PB(0.207 mg CO2 m-2d-1) and UA(0.098 mg CO2 m-2d-1). As a consequence, a separation into pits/mounds would be important for a precise budgeting of greenhouse gases.     

沼液对地膜小麦根系及产量影响研究

沼液浸种的地膜小麦具有合理的产量结构，比地膜小麦增产9.88%，比露地小麦增产67.65%，苗期着重促进了根系的发育，中后期更快地促进了地上部的生长发育，使植株的抗逆性增强。喷施叶面肥均表现为增产，其中KH₂PO₄效果最好，增产幅度11.94%～13.92%，其余依次为麦丰乐、沼液、红苹果2号，增产幅度不足6%，同时提高了株高、成穗数、穗粒数和粒重。     

无机盐对乙酸底物甲烷发酵动力学的影响

厌氧发酵反应器中的甲烷化以乙酸降解途径为主。已知的数十属产甲烷菌中只有Methanothrix和Methanosarcina以乙酸为底物,其中Methanothrix常为消化器中的主力。该文以乙酸为碳源培养了Methanothrix优势菌液,分析了温度与无机盐对甲烷发酵的动力学影响。结果表明,通过调整无机盐浓度,可使常规浓度培养液的总反应速度常数提高8倍,对Methanothrix产甲烷有显著影响;以研究较为成熟的温度因素作参照,当温度与无机盐在工程范围变化时,引起的动力学常数的变化幅度分别为0．01～0．43和0．04～0．59,无机盐与温度具有相同数量级的影响力。此外,该文采用适于厌氧水解的动力学模型研究乙酸底物甲烷发酵过程,结果表明,其产甲烷进入对数期后与试验数据基本吻合。     

Methane production and consumption in a cultivated humisol

Summary Laboratory studies were conducted on a cultivated humisol containing populations of both methanotrophs and methanogens. The molar ratio CO₂ produced : O₂ consumed :CH₄ consumed was 0.27:1.0:1.0. Methane oxidation showed typical Michaelis-Menten kinetics with apparent K _m values for CH4 and O₂ of 66.2 M and 37.0 M, respectively. The low CO₂ yields and the effects of low dissolved oxygen indicated the presence of aerobic obligate methanotrophs. It is suggested that the methanotrophs in this soil are not entirely dependent on atmospheric CH₄ for growth and survival in situ.     

氮肥、土壤湿度和温度对稻田土壤甲烷氧化的影响

Effects of nitrogen fertilizer,soil mosture and temperature and temperature on methane oxidation in paddy soil were investigated under laboratory conditions.Addition of 0.05 g N kg^-1 soil as NH4Cl strongly inhibited methane oxidation and addition of the same rate of KCl also inhibited the oxidation but with more slight effect,suggesting that the inhibitory effect was partly caused by increase in osmotic potential in microorganism cell,Not only NH4^ but also NO3^- greatly affected methane oxidation.Urea did not affect methane oxidation in paddy soil in the first two days of incubation,but strong inhibitory effect was observed afterwards.Methane was oxidized in the treated soil with an optimum moisture of 280 g kg^-1 ,and air-drying inhibited methane oxidation entirely.The optimum temperature of methane oxidation was about 30℃ in paddy soil.while no methane oxidation was observed at 5℃or 50℃。