Effects of biogas digestion of clover/grass-leys, cover crops and crop residues on nitrogen cycle and crop yield in organic stockless farming systems

The trend towards specialization in conventional farming led to large agricultural areas in Germany and in Europe lacking livestock. Also stockless organic farming has increased during recent years. In organic farming clover/grass-ley (CG) provides nitrogen (N) to the whole cropping system via symbiotic N₂ fixation and also controls certain weeds. A common practice in organic farming, when ruminants are not present, is to leave the biomass from CG in the field for their residual fertility effect. CG biomass, crop residues (CR) and cover crops (CC) represent a large unexploited energy potential. It could be used by anaerobic digestion to produce biogas. A field experiment was carried out by implementing a whole cropping system with a typical crop rotation for such farming systems on the research station Gladbacherhof from 2002 to 2005. The crop rotation consisted of six crops (two legumes and four non-legume crops). The aim was to evaluate whether the use of N could be improved by processing biomass from CG, CR and CC in a biogas digester and using the effluents as a fertilizer, compared to common practice. In the control treatment, represented by the usual stockless system, the CG, CR and CC biomass were left on the ground for green manure purposes. In the biogas systems these substrates were harvested for digestion in a biogas plant. The effluents of digestion were used to manure the non-legumes in the same crop rotation. Results indicate that digestion of CG, CR and CC can increase the crop dry matter and N yields and the N content of wheat grains in organic stockless systems. Harvesting and digestion of residues and their reallocation after digestion resulted in a better and more even allocation of N within the whole crop rotation, in a higher N input via N₂ fixation and lower N losses due to emissions and probably in a higher N availability of digested manures in comparison to the same amounts of undigested biomass.     

The analysis of China wind power industry

The development course of China wind power industry is reviewed by six stages. National policies on wind power industry are elaborated from the aspects of laws & regulations, planning, finance & taxation and electrovalence policy. And these policies have played an important supporting and regulating role in the development of wind power industry. The development status of China wind power industry is analyzed based on wind turbine installed capacity, wind power output and their growth rate. It is explained that national wind turbine manufacturers have kept developing and become strong by the data of new global installed capacity share of mainland wind turbine manufacturers in 2013 and the new global market share of 8 domestic enterprises among the world top 15 wind turbine manufacturers. But there are still 5 key problems which influence the development of national wind turbine need to be solved, including lack of top-level design, abandon and restriction wind power seriously, lack of R&D abilities, some of the key parts relying on imports and wind turbine facing a quality guarantee dilemma. Taking Sinovel Wind Group Co. Ltd. and Xinjiang Goldwind Sci & Tech Co. Ltd., the two leading companies as an example, their performance is analyzed and it’s pointed out that the wind industry must keep vigilant after the overspeed development. The enterprises should try to avoid neglecting cultivating their inner core competitive ability, including technology advancements and products reliability. Occupying the market with low price competition and expanding blindly is also not desirable. At last, the development prospects of our country’s wind power industry are analyzed and three proposals are put forward.     

湘潭市雨湖区产业扶贫现状及对策分析

"十三五"时期,湘潭市雨湖区扶贫工作的主要任务是发展产业扶贫,进一步巩固脱贫成效。分析了该区蔬菜、特色水产、花卉苗木、生猪及水稻等5个产业发展现状和市场地位,就全区发展产业扶贫的优劣势进行分析,提出了抓好产业培育、加大政策扶持、优化资源配置、强化科技支撑、完善利益联结机制、夯实组织保障等发展建议。     

福建安溪茶产业集群形成机制研究

福建安溪的茶产业集群经过长期的发展,取得了显著的成效。福建安溪茶产业集群形成的内部优势包括区域资源禀赋、产业链迂回、龙头企业推动等,外部力量主要是市场催生、政策拉动以及独特的传统社会文化环境等。建议农业产业集群发展要在农户层面、企业层面和产业集群层面做好政策支持。     

工厂化养殖仿刺参营养品质分析与评价

为了更好地了解工厂化养殖仿刺参的营养成分和品质,本研究采用国标等方法,分别对工厂化养殖、池塘养殖、底播自然生长和海捕野生仿刺参的各项营养成分进行了分析和评价。结果显示,工厂化养殖仿刺参出皮率为62.7%~65.8%,煮后出皮率为24.8%~31.1%,显著高于其他来源仿刺参。工厂化养殖仿刺参的必需氨基酸/非必需氨基酸为0.46~0.50,氨基酸营养价值平均得分为87.89~90.42,均高于其他来源仿刺参,说明其氨基酸营养价值水平较高。在其他营养成分方面,工厂化养殖仿刺参与池塘养殖仿刺参较为相近。自然环境生长仿刺参由于摄食来源广泛、生长周期较长,其蛋白质与脂肪水平普遍高于其他来源仿刺参。综合分析认为,工厂化养殖仿刺参的营养价值与池塘养殖仿刺参相近,在出皮率和氨基酸营养水平上优于池塘养殖和自然环境生长仿刺参,说明工厂化养殖仿刺参具有较好的品质和营养价值。     

山西省水资源产业贡献度及生态用水效益分析

研究水资源对产业的贡献度和生态环境效益可以为合理配置水资源提供依据.首先,通过分析山西省水资源的状况,在改进的C-D模型的基础上,测算出水资源对区域生产总值的贡献度为-1.3％,其中第一、二、三产业分别为2.11％、0.50％和-1.56％,在此基础上定量分析山西省生产用水对经济的作用;其次,以森林生态系统为例,核算山西省2003和2010年森林生态服务功能价值分别为974.08亿和1000.21亿元,相应的用水量分别为3.1亿和3.4亿m3,并分析山西省森林生态用水的效益.针对山西省生产用水与生态用水配置存在的浪费、污染严重的问题,提出节约用水、防治水污染、保障生态用水等对策.     

丘陵山区不同种植型乡村产业融合水平测度及障碍因子诊断

为探明乡村产业融合水平的差距及障碍因子,该研究基于重庆市（江津）现代农业园区6镇15个样点村的调研数据,从产业融合行为、融合效益2个维度构建指标评价体系,采用熵权-TOPSIS法、耦合协调度模型和障碍度模型,测算不同种植型乡村产业融合水平,并诊断其障碍因子。结果表明：1）样区乡村产业融合水平整体偏低,均值仅0.210。分产业类型来看,花椒型（0.399）>粮油型（0.254）>花木型（0.134）=蔬菜型（0.134）>水果型（0.127）。从同类产业乡村差距来看,花木型、蔬菜型和水果型乡村之间融合水平差值均低于0.110,但花椒型和粮油型乡村差距较大,分别为0.732和0.361。2）乡村产业融合耦合协调水平不高,14个样点村处于不同程度的失调状态,占比近93.33%。耦合协调度最大的是花椒型乡村（0.436）,其次是粮油型乡村（0.369）,最后依次是蔬菜型（0.291）、花木型（0.285）和水果型（0.274）乡村。同类乡村内部之间的耦合协调度差距也较大,花椒型（0.372）>粮油型（0.201）>水果型（0.157）>蔬菜型（0.098）&...     

东北林业大学重点课程“生产计划与控制”建设研究

“生产计划与控制”是东北林业大学工业工程专业的主干课程之一.本课程的建设强调在社会主义经济环境下将理论与实践相结合,针对性、实用性强.本文结合生产计划与控制教学实践,从生产计划与控制课程建设目标、教学体系改革、师资队伍建设和课程网站建设等方面对生产计划与控制课程建设进行全面的研究和探讨.逐步实现课程的整体优化,力图使教育发挥全面效应.     

天津市产业碳排放的影响因素及贡献

[目的] 综合考虑“水—土—能—碳”相互关系,研究产业碳排放的影响因素及贡献,为天津市减排决策制定提供一定依据。[方法] 对天津市产业碳排放进行测算,将水土资源因素引入Kaya恒等式,运用LMDI模型计算产业碳排放各影响因素的贡献。[结果] 2004—2018年天津市各产业碳排放均呈现上升趋势;整体来看,水资源经济产出、人口数量促进天津市各产业碳排放,且前者为主要促进因素,水土资源因素抑制各产业碳排放,碳排放强度促进农业碳排放,而抑制其他产业碳排放,人均用地面积抑制农业碳排放,而促进其他产业碳排放;水土资源因素对各产业碳排放影响的变化与水土资源匹配度变化有较好的一致性,单位用地面积用水量越多,其对碳排放的促进作用越大。[结论] 为实现节能减排,应发展节水产业,优化城市水土资源开发利用,发挥水土资源因素对碳排放的抑制作用。     

典型煤矿工业园区土壤重金属污染评价

随着工业化进程的加快,一些农业用地转为工业用地,土地用途的转变可能会影响周围土壤的质量。该研究以河南省东部某煤矿工业园区为对象,分成不同小区采集土壤样品,分析工业园区内表层土壤的Hg、Cd、Zn、As、Pb、Cr六种重金属含量及污染评价,并同时与周边土壤重金属含量进行比较,分析可能造成土壤环境污染的因子。结果表明,根据土壤环境质量标准,工业园区域内土壤污染指数小于0.7,土壤清洁;但与周边土壤比较存在污染的风险,潜在重金属威胁主要表现为Hg,其他重金属污染风险趋势为Cd>Zn>As>Pb>Cr;在空间分布上,除Cr外,随着与工业园区距离的加大,其他五种重金属其含量有降低的趋势;同时根据结果提出合理土壤污染防控建议。