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1.
郑书高 《畜牧兽医科学(电子版)》2021,(4):182-183
近年,畜牧养殖业蓬勃发展,过去的区域化散养已经基本不存在,养殖结构逐渐向集约化、一体化、规模化过渡,养殖规模也逐渐增大。养殖副产品肉、蛋、奶等极大满足了人们的生产生活,养殖中产生的尿液、粪污对生态环境造成极大影响。为促进规模化养殖实现绿色健康发展,该文分析规模化畜牧养殖对生态环境的破坏及防治措施。 相似文献
2.
为了保护珍贵的十里香茶树资源,掌握利于十里香茶的最优组培条件,本研究对十里香茶组培过程中外植体类型、消毒时间、培养基添加物及培养条件进行了筛选。结果表明,采用轻微木质化的带腋芽茎段经升汞消毒15 min,接种后暗培养5 d,MS+0.2 mg·L^-1 NAA培养基中添加3 mg·L^-1 PVP+2000 mg·L^-1 Vc或者6 mg·L^-1 PVP+3000 mg·L^-1 AC,可在低污染率的前提下将褐化率降为10%左右,一定程度上解决了茶树组培中褐化率高的难题;采用1/8 MS+1 mg·L^-1 IBA培养基有利于外植体生根且增殖迅速。本研究建立了十里香茶的无菌苗离体培养及再生体系,可通过组培手段对其进行大量繁殖。 相似文献
3.
Soil protection for a sustainable future: options for a soil monitoring network for Ireland
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The increased recognition of the importance of soil is reflected in the UN Post‐2015 Development Agenda with sustainable development goals that directly and indirectly relate to soil quality and protection. Despite a lack of legally binding legislation for soil protection, the European Commission remains committed to the objective of soil protection. However, the achievement of a legally binding framework for soil protection relies on the implementation of a soil monitoring network (SMN) that can detect changes to soil quality over time. As beneficiaries do not pay for the provision of soil information, the options for soil monitoring are limited. The use of existing data sets should be considered first. Using Ireland as an example, this research explored the opportunities for a SMN for Ireland considering three existing national data sets. The options for a SMN are considered in terms of their spatial and stratified distribution, the parameters to be measured and an economic analysis of the options proposed. This research finds that for Ireland, either a 10 or a 16 km2 grid interval stratified by land use and drainage class offers the best potential in relation to the spatial distribution of existing data sets to reflect local data at a national level. With existing data, the stratified SIS data using the 16 km2 grid offers the best value for money, with baseline costs for analysis, excluding field costs, of between €706 481 and €2.8 million. Acknowledging the impossibility of measuring all parameters with ideal frequency, this study proposes a two‐tier system for optimized monitoring frequency. Parameters must anticipate future policy requirements. Finally, the implementation of a SMN must be accompanied by standardized methods, defined thresholds and action mandates to maintain soil quality within allowable limits. 相似文献
4.
呼和浩特市大气污染状况的研究及遥感信息的利用 总被引:1,自引:0,他引:1
利用遥感技术结合地物波谱测定和叶表面内大气污染元素的含量测定分析研究大气污染是一种有效可靠的方法。克服了常规大气监测的弊病。充分显示了快速、准确的优越性。为城市规划和环境的综合治理提供了可靠的科学依据。 相似文献
5.
浅论网络信息污染及其防治对策 总被引:3,自引:0,他引:3
谭文华 《农业图书情报学刊》2004,15(3):69-71,79
简要阐述了网络信息污染的具体表现形式及其带来的危害作用,提出了防治信息污染的对策。 相似文献
6.
本文用约1000块样地资抖,系统地研究了黑龙江省落叶松人工林的地位指数级导向曲线模型。通过林业统计分析软件Statistica6.0对各落叶松人工林数据进行拟合、分析比较,结果为:从拟合精度、曲线走向与散点分布趋势、残差分布等综合考虑,舒马切尔曲线函数比较适合落叶松人工林地位指数级导向曲线模型的拟合。 相似文献
7.
A.J.A. Vinten D.R. Lewis D.R. Fenlon K.A. Leach R. Howard I. Svoboda I. Ogden 《Soil Use and Management》2002,18(3):223-231
Abstract. Slurry from farm animals may contaminate water supplies, rivers and bathing waters with faecal coliforms, such as Escherichia coli . Where animals harbour the O157 strain the hazard to human health is particularly high, but both the hazard level, and the low incidence and sporadic nature of the excretion of E. coli O157 make it difficult to study this strain under field conditions. The survival of total E. coli and of E. coli O157 were compared in the laboratory for two soils under controlled temperature and moisture. E. coli O157 die-off rate was the same as or quicker than for total E. coli . This result meant that field experiments studying the fate of total E. coli should give a satisfactory evaluation of the risk of water contamination by the O157 strain. In four field experiments at three sites, slurry containing total E. coli numbers of 2.2 × 104 to 5.7 × 105 colony forming units per mL (c.f.u. mL–1 ) was applied to drained field plots. Field die-off was faster than expected from laboratory experiments, especially in one experiment where two weeks dry weather followed application. In all but this experiment, the first drain flow events after slurry application led to very high E. coli concentrations in the drains (103 to 104 c.f.u. mL–1 ). E. coli O157 was present in the slurry used for two of the experiments (33 c.f.u. per 100 mL in each case). However the proportion of E.coli O157 was very low (about 1 in 105 ) and it was not detected in the drainage water. After the first week E. coli drainage water numbers decreased rapidly but they were 1–10 c.f.u. mL–1 for much of the sampling period after slurry application (1–3 months). 相似文献
8.
沈阳空气污染的主要成因 总被引:1,自引:0,他引:1
方向阳 《青岛农业大学学报(自然科学版)》2002,19(3)
介绍了导致中国沈阳空气污染严重的主要原因 ,并提出了解决这些问题的一些措施。在一定程度上 ,沈阳所面临的空气污染情况在中国北方城市是相当典型和普遍存在的 相似文献
9.
畜牧业生产中的环境污染及治理对策 总被引:22,自引:3,他引:19
本文阐述了畜牧业生产中产生的畜禽粪尿、有机废水等废弃物对环境造成的污染,探讨了治理畜牧业污染的措施,提出了发展生态畜牧业的思路。 相似文献
10.
Hao Wenkang Lang Kuijian Zhang Yanli Li Longchang Weng Guoqing Huang Mingquan Wang Xiangguo 《林业研究》1993,4(2):33-42
Site quality of larch (Larix gmelinii Rupr.) in Da Xingan Mountain in Inner Mongolia was studied systematically with about 1000 temporary plots and computer software.
The nature of site class and site index curve was discussed in view of general mathematical model of height growth. The height
growth of dominant tree of four divisions of forest stands were studied and site index tables were constructed respectively.
In order to unify the comparing standard and convenience for management in this region, site index table was constucted too.
Based on discussing the action and accuracy of forest type, a series of site quality evaluation (forest type-site index class-site
index) was suggested.
This subject of study is supported by the National Natural Scientific Fund (No. 39270549). 相似文献