Growth and physiological responses of growing pigs to wheat–corn distillers dried grains with solubles

Gaining a detailed knowledge on the impact of a feedstuff on pig growth and physiological responses is critical for its effective utilization. Thus, the purpose of this study was to investigate the effect of distillers dried grains with solubles derived from co‐fermentation of wheat and corn (wcDDGS) on performance, carcass and visceral organ weights, whole‐body O₂ consumption and heat production (HP) in growing barrows. The experimental diets were as follows: corn–soybean meal diet (Control), Control + 15% wcDDGS and Control + 30% wcDDGS. In Exp. 1, 48 pair‐housed pigs of average BW 18.6 ± 1.5 kg (mean ± SD) were allotted to the 3 diets (n = 8). Pigs had free access to water and feed for a 28‐day period during which ADG and ADFI were calculated weekly. Thereafter, 1 pig/pen was killed to measure carcass and visceral organ weights. Overall, wcDDGS linearly decreased (p < 0.05) ADFI and ADG but had no effect on G:F (p > 0.10). The ADFI was 1.55, 1.45 and 1.36 kg/day for diets containing 0, 15 and 30% wcDDGS respectively; corresponding values for ADG were 0.79, 0.75 and 0.67 kg/day respectively. A linear decline (p = 0.01) in eviscerated hot carcass weight was observed as dietary wcDDGS increased. In Exp. 2, 18 pigs of average BW 20.4 ± 2.4 kg (mean ± SD) were individually housed in metabolism crates and fed the 3 diets (n = 6) at 550 kcal ME kg BW^?0.60day for a 16‐day period followed by measurement of O₂ consumption using an indirect calorimeter. Diet had no effect (p > 0.10) on whole‐body O₂ consumption and HP. In conclusion, increasing wcDDGS content in growing pig diets linearly reduced ADFI, ADG and eviscerated hot carcass weight but had no effect on G:F, visceral organ weights or HP.     

木耳属4个野生菌株的培养特性研究

通过研究不同营养和环境条件对木耳属4个主要种类的野生菌株生长速率和生长势等培养特性的影响,明确了黑木耳、毛木耳、皱木耳、紫木耳菌丝生长的最适温度范围以及最佳碳源和氮源。     

江苏省水稻生产的碳排放结构特征和影响因素研究——基于农户生产投入和规模的视角

基于对江苏省水稻生产农户的实地调研,运用投入产出法和生命周期法,对水稻生产的碳排放进行探究,并借助影响因素回归模型,探讨影响农户水稻生产碳排放的主要因素.结果表明：①江苏省农户生产1 hm2水稻的碳排放约为5 110.92 kgCe,从水稻碳排放结构特征来看,水稻生产中甲烷排放的比重较大,包括农用能源（煤炭、柴油、电力）及工业投入品（化肥、农药等）的全生命周期碳排放是水稻温室气体重要的来源;②家庭劳动力数量的增加并不会减少水稻单位产量的碳排放;③种植规模对水稻单位产量碳排放的影响显著为负,且种植规模效益地区差异明显.     

《土壤肥料学》教学过程中固碳思想的融入与加强探讨

介绍了固碳思想产生的背景,在此基础上提出《土壤肥料学》教学过程中固碳思想融入与加强的必要性,并从提高教师专业素质,优化课程教学内容,丰富课程教学方法,注重实践能力培养等方面探讨了实现途径.     

旅游交通能源消耗与碳排放研究

旅游业作为世界上最大的产业部门,其能源消耗和碳排放已经引起关注,其中旅游交通作为旅游业能源消耗和碳排放最主要的部门,许多学者对其进行了研究.科学全面地分析旅游交通能源消耗和碳排放有助于推动旅游交通的可持续发展,进而促进旅游业更健康地发展.分析了当前旅游交通能耗和碳排放的研究方法,然后从旅游交通能源消耗和碳排放的测度、影响因素、对环境的影响和响应对策等4个方面,综述了其主要的研究内容,最后对中国旅游交通能源消耗和碳排放的研究提出了建议.     

长白山8种林型土壤有机碳和全氮的质量分数及垂直分布特征1）

基于样地调查和室内分析,比较研究了长白山地区典型的8种森林类型土壤有机碳和全氮的质量分数、碳氮比、碳密度和氮密度的分布特征。结果表明,8种林型土壤有机碳和全氮的质量分数变化范围分别是36．99～70．33、3．14～6．04 g· kg－1,有机碳、全氮质量分数最大的林型均是阔叶混交天然林。红松天然林土壤C ／N值最大为15．56,其它C ／N值变化范围为10．55～12．19。在土壤垂直剖面上,随着土层深度的增加,土壤的有机碳、全氮质量分数随之递减,土壤密度随之递增。8种林型土壤碳密度是杨树天然林最大,为22．13 kg· m－2,氮密度是落叶松人工林最大,为1．97 kg· m－2;针阔混交人工林的碳密度和氮密度均为最小,分别是12．37、1．11 kg· m－2。     

苏州主要园林树种的光合固碳能力对比分析

园林树种的光合固碳能够维持城市空气中CO2和O2的平衡。以苏州地区32个园林树种为材料,利用Li-6400便携式光合作用仪测定了其光合日变化,并利用测定结果计算其日净固碳能力,再以聚类分析法对其日净固碳量进行分类。结果如下:第1类[日净固碳量极高,17.55~18.76 g/(m2·d)]有紫荆、枫杨、垂柳,第2类[日净固碳量高,12.25~16.02 g/(m2·d)]有大叶女贞、乌桕、榉树、枫香树、垂丝海棠、樱花、夹竹桃,第3类[日净固碳量中等,8.57~11.97 g/(m2·d)]有银杏、红花檵木、朴树、乐昌含笑、红叶李、杜英、海桐、金边黄杨、杜鹃、重阳木、樟树、金丝桃、红叶石楠,第4类[日净固碳量低,3.81~7.64 g/(m2·d)]有红枫、洒金东瀛珊瑚、金叶女贞、八角金盘、五角枫、鹅掌楸、紫薇、木芙蓉、桂花。上述分析结果可对苏州的园林规划及树种选择提供一定的理论指导。     

两种施肥情景对温室气体排放和经济成本的影响——以山东滕州和兖州为例

本研究对山东滕州和兖州的施肥状况进行入户调查,借鉴农田管理措施的固碳速率和温室气体(GHG)排放的计算方法,根据农业部的施肥建议设定不同推荐情景,估算施肥现状和推荐情景对GHG净排放和经济成本的影响。结果表明,小麦和玉米都采用推荐用肥能明显减少GHG排放和经济成本,特别是玉米采用基追结合,滕州和兖州的排放分别减少300 kgCe/(hm2·a),成本减少2 700元/hm2,化肥碳效率增加超过30%。总之,农业部施肥建议的推广应用具有重要的环境和经济价值。     

Belowground carbon allocation patterns in a dry Mediterranean ecosystem: A comparison of two models

Total belowground C allocation (TBCA) accounts for a large fraction of gross primary production, it may overtake aboveground net primary production, and contributes to the primary source of detrital C in the mineral soil. Here, we measure soil respiration, water erosion, litterfall and estimate annual changes in C stored in mineral soil, litter and roots, in three representative land uses in a Mediterranean ecosystem (late-successional forest, abandoned agricultural field, rain-fed olive grove), and use two C balance approaches (steady-state and non-steady-state) to estimate TBCA. Both TBCA approaches are compared to assess how different C fluxes (outputs and inputs) affect our estimates of TBCA within each land use. In addition, annual net primary productivity is determined and C allocation patterns are examined for each land use. We hypothesized that changes in C stored in mineral soil, litter and roots will be slight compared to soil respiration, but will still have a significant effect on the estimates of TBCA. Annual net primary productivity was 648 ± 31.5, 541 ± 42.3 and 324 ± 22.3 g C m⁻² yr⁻¹ for forest, abandoned agricultural field and olive grove, respectively. Across land uses, more than 60% of the C was allocated belowground. Soil respiration (F_S) was the largest component in the TBCA approaches across all land uses. Annual C losses through water erosion were negligible compared to F_S (less than 1%) and had little effect on the estimates of TBCA. Annual changes in C stored in the soil, litter layer and roots were low compared to F_S (16, 24 and 10% for forest, abandoned agricultural field and olive grove, respectively), but had a significant effect on the estimates of TBCA. In our sites, an assumption that Δ[C_S + C_R + C_L]/Δt = 0 will underestimate TBCA, particularly in the abandoned agricultural field, where soil C storage may be increasing more rapidly. Therefore, the steady-state model is unsuited to these Mediterranean ecosystems and the full model is recommended.