规模化猪场清粪工艺比选分析

生猪产业是中国畜牧业的主导产业,是城乡居民"菜篮子"产品的重要组成部分。随着生猪产业的持续发展,养殖所产生的粪便污染对环境的影响也日益突出,逐渐成为重要的农业面源污染之一。作者简要论述了生猪养殖对环境的影响,分析了当前生猪养殖的几种重要清粪工艺,对规模化猪场清粪工艺进行了比选分析,并提出了规模化猪场清粪工艺选择的建议。     

Effect of genotype and environment on flavonoid concentration and profile of black sorghum grains

In recent years, colored sorghum genotypes high in flavonoids have been developed. Flavonoid levels of eight black sorghum genotypes grown in four locations in Texas were evaluated to assess the relative genotype, environment and genotype × environment effects. Levels of total 3-deoxyanthocyanidins ranged from 292 μg/g to 499 μg/g and 251 μg/g to 804 μg/g across environments and genotypes, respectively. Total 3-deoxyanthocyanidins in sorghums from Halfway were low (178–694 μg/g) due to the reduction of their non-methoxylated forms. This reduction is likely due to significant grain weathering which was observed only at Halfway. In addition, flavanone and flavone levels were the lowest at Halfway with levels of 12 μg/g and 78 μg/g, respectively. For all flavonoids there was a genotype by environment interaction (p < 0.01) which suggests that environment had a different effect on flavonoid levels depending on the genotype. Color values L*, a* and b* did not correlate with flavonoid content. Due to genotype, environment and their interactions, sorghum breeders must evaluate these traits in multiple environments to identify genotypes with high and stable production of flavonoid compounds.     

新疆棉区残膜污染及其治理技术

针对新疆棉区地膜使用后存在的问题,分析了典型地区的残膜污染现状,指出棉区残膜回收分3个作业阶段。介绍了残膜回收机械的最新研究进展及其典型机具使用中的优缺点,最后针对新疆棉区现有残膜治理技术存在的问题提出了相应的对策和方法。     

四川省白鹿河流域非点源氮磷负荷来源及控制对策

在现场调研基础上,应用国内外通用的输出系数模型,计算了四川省白鹿河流域总氮总磷负荷,并与通用土壤侵蚀方程计算值进行了对比,之后,深入分析了白鹿河流域总氮总磷产生的来源。针对四川省彭州市白鹿镇灾后重建规划,提出了减小白鹿河流域总氮总磷负荷的对策措施。它对于四川省灾后重建,水源地保护、水环境管理有十分重要的意义。     

珠三角主要工业区周边蔬菜产地土壤重金属污染调查分析

采集珠三角地区主要工业区周边蔬菜产地土壤,研究土壤中铅(Pb)、镉(Cd)、汞(Hg)、砷(As)、铬(Cr)5种重金属的含量与分布特征。参照国家土壤环境质量标准(GB15618-1995)中的二级标准,采用单项污染指数法和综合污染指数法,对其重金属污染现状进行评价。结果表明：232份土壤样品中,Cd、Hg、As、Cr的超标率分别为45.06%、7.73%、5.15%和1.29%,未见Pb超标;37.34%的土壤受到不同程度的污染,Cd污染情况最为严重,Hg污染次之;土壤污染以单一重金属污染为主,未出现3种及以上重金属复合污染。各地污染状况呈现区域差异,东莞地区受污染的样品比例较大,珠海和广州的污染情况相对较轻。该区域的土壤重金属污染形势不容乐观,其可能给农业生产带来的风险应引起重视。     

Variations in the morphological characteristics of Stipa tenacissima fiber: The case of Tunisia

Esparto fibers are cellulose-based fibers extracted from esparto (Stipa tenacissima) leaves. Morphological characteristics (length, width, and coarseness) of esparto fibers are analyzed in relation to growing conditions and plant biology. Seven localized sites in Kasserine in central western Tunisia are examined. The analysis of variance showed that all investigated characteristics vary significantly with site, season, and leaf level. Leaves reach minimum level in winter and maximum level in fall. Fiber differentiation is closely related to the vegetative cycle. Fibers are short and wide at the leaf base (basal level) and grow longer and thinner above the leaf. Results on the raw material (esparto leaves) were confirmed by results on esparto pulp.     

云南元江山地香蕉无公害栽培

元江是云南最适宜发展香蕉的区域之一,目前坝区香蕉种植开始往山地发展。山地土壤灌溉条件以及香蕉栽培的特殊性,导致山地香蕉生产难以产生较好的经济回报。通过近几年山地香蕉栽培实践,总结了一套山地香蕉无公害栽培关键技术,解决了山地香蕉栽培的特殊性与土壤水肥灌溉条件的矛盾。     

植物组织培养中污染控制技术的研究现状

分析了植物组织培养过程中的污染原因,结合外植体消毒技术的研究现状,提出如何控制由外植体引发污染的方法。选择合适的外植体和消毒剂,采用联合消毒方法,对外植体初代培养中内源污染的控制效果比较明显。另外,对于难消毒的外植体,配合使用抗生素能有效地控制污染。     

西宁市蔬菜基地蔬菜体内As污染及累积效应研究

随着工业化的快速发展,工业上的废气、废水、固体废弃物的排放量日益增多,加之花费以及农药等的不合理使用,造成了土壤中的重金属累积,从而对蔬菜造成了污染,严重威胁着人类的健康。随着人们生活水平的不断提高,人们对蔬菜中的重金属污染越来越加以重视,选取西宁市的新庄镇蔬菜生产基地,来对蔬菜以及土壤中的As浓度进行测定,并进行了差异分析以及相关性的分析。