昭平镇抛栽稻纹枯病严重发生的原因及防治

为了摸清昭平镇近年抛栽稻纹枯病严重发生的原因,从纹枯病的菌源量、水稻的栽培管理水平、稻飞虱的发生程度、气候条件、防治措施等5方面进行调查和分析,结果表明,稻纹枯病造成的稻谷损失为各种病虫害之首,必须引起足够的重视。采取减少菌源,加强水肥管理,适时使用药剂防治等5个相应的综合防治对策,效果显著。     

湖北省城乡发展差异的时空特征与成因及对策建议

以1980-2009年的经济数据为基础,从收入水平、消费水平、农业与非农业生产率二元差异方面,分析了湖北省城乡发展差异的时空特征.结果表明:湖北省城乡发展差距呈现波动性特征,且近年来有不断扩大趋势;其主要影响因素包括城乡分割的二元结构、城乡产业结构差异和农业产业化水平低等,同时提出了深化制度改革、调整和优化产业结构、发展农村非农产业以及加快鄂西生态文化旅游圈发展等缩小城乡差异的对策建议.     

气候资源开发利用与安徽省农业可持续发展

从气候资源对农业生产的重要性出发 ,根据安徽省气候资源的特点和开发利用现状 ,分析了安徽省农业可持续发展所面临的气候资源方面的问题 ,指出今后气候资源开发利用的主要途径 ,并提出了近期加强气候资源开发利用的几项措施     

基于气象业务网络的农村经济信息网络服务系统设计与实现

利用气象部门技术和装备优势，采用双向纵横联网方式及“互联网＋电视＋广播＋报纸＋墙报＋信息小报＋121电话”的信息分发和传播模式，建立基于气象部门卫星业务网络、INTERNET网络、传真等方式的市、县（区）、乡信息快速汇交平台为一体的农村经济信息网络服务系统。     

西南某高速公路隧道病害成因分析及处治设计

公路隧道常见的质量问题主要有隧道衬砌渗漏、衬砌开裂、限界受侵等,产生这些问题的原因是多方面的,如地质原因、施工原因等。针对西南某高速公路隧道病害整治工程,介绍了病害的主要类型、产生的原因、整治方案、施工流程,旨在为类似隧道病害整治工程提供工程借鉴。     

Extent and Management of Low pH Soils in Ghana

A review of soil acidity problems with regards to causes, extent and management in Ghana shows that the extent of soil acidity has changed within a period of 2–3 decades. In the 1970s' soil acidity was a major problem in the Western region and the lowlands. Oxisols and Ultisols are common soils found in this area. However, anthropogenic causes have augmented natural causes resulting in more low pH soils. Soil acidity has therefore become a serious problem throughout the country. Anthropogenic causes identified include general agronomic practices such as tillage, use of mineral fertilizers and continuous cultivation. Rates of 1–2 t ha⁻¹ lime on ultisols and oxisols in Ghana are more than adequate to meet the calcium demands and sufficient to neutralize residual acidity of any nitrogen fertilizer. Addition of organic amendments on low pH soils was also found to be beneficial and resulted in increased yields. The adoption of the "sawah" technology for lowland rice production has also resulted in improved water management, increased nutrient availability and significant increases in rice yields.     

Relative effects of management and environmental conditions on performance and survival of populations of a terrestrial orchid, Dactylorhiza majalis

For population viability analysis of endangered orchid populations, it is crucial to disentangle the effects of weather and management from intrinsic orchid dynamics. When doing this, typically several months’ average temperatures and/or sums of precipitations are compared with some characteristics of plant performance. Here we tested, whether short averaging intervals (1-2 weeks) are more closely correlated with orchid performance. We used 5 years of data from five Dactylorhiza majalis populations, and have shown that the improvement of prediction by shortening the interval over which the temperatures are averaged or precipitation summed, even if detectable, is only weak and not significant. This, however, may be due to low weather variability during the study. Regarding the second aspect, the effect of management (presence or absence of mowing), we have found that leaf area of D. majalis at the regularly mown site was larger than that at the sites which were mown only once in 2 years, but we did not detect a significant effect of the absence of mowing on the incidence of flowering. Mowing can affect orchid performance in two ways: by reduced shading of orchids and by reducing competition with other species. Therefore, we have determined the co-occurring species associated with presence or absence of mowing and found that shading significantly affected the length of the flower stalk, the ratio of leaf width to leaf length at the end of the season, but did not affect seed weight and probability of flowering the next year. We conclude that the most appropriate management for D. majalis is mowing at least once a year, ideally at the end of June/beginning of July, after its fruiting.     

Decomposition in five woodland soils: relationships with some invertebrate populations and with weather

Summary In two alluvial forests, a beech forest, an oakhazel-wood and a spruce forest, correlations between abiotic factors and the different groups of soil animals on the one hand and the decomposition rate (mean rate of disappearance) on the other hand have been the subject of investigation. There is a positive correlation between Lumbricidae and Brachycera imagines and the pH and the decomposition rate, but a negative one with Enchytraeidae and Nematocera imagines.Varying weather conditions are of great importance for decomposition processes. The influence of temperature seems to be insignificant. In the deciduous forests fluctuations of precipitation correlate fairly well with fluctuations in rates of decomposition, because of the high abundance of lumbricids. The spruce forest has very few lumbricids and the influence of weather on the course of decomposition is insignificant. Yet there is only a very loose relationship with the annual fluctuations of weather conditions. Only a major event such as the relatively low temperature and precipitation of 1980 is capable of inhibiting the development of sciarid larvae and enchytraeids and hence reducing the ensuing decomposition rate in 1981 and possibly even in 1982. The reason for this is that sciarid larvae and imagines, for example, go through critical periods during their development, which are influenced by the weather, frequently with a time lag of 1 year.Long-term investigations in the spruce forest have established a high correlation between sciarid larvae and enchytraeids and the decomposition rate.Dedicated to the late Prof.Dr. M.S. Ghilarov     

2008年娄底冰雪灾害成因分析

2008年1月13日~2月5日,娄底市出现了有气象记录以来强度最强、持续时间最长的冰冻雨雪灾害。在此通过天气形势及各物理量分析,研究发生此次天气过程的主要原因。结果表明,欧亚大陆长时间维持两槽一脊形势,有利中高纬度冷空气南下,中纬度地区长时间维持浅槽天气形势,槽前强盛的西南气流为娄底市冰雪天气提供充沛的水汽来源,对流层中低层冷暖气流形成的辐合带是影响娄底市冰雪天气稳定的天气系统;湖南中南部对流层中低层长时间存在次级环流、深厚的逆温层、逆温层中低层的水汽辐合,这些对娄底市长时间维持冰雪天气起主要作用。     

黑龙江省主要生态环境问题及成因分析

论述了黑龙江省生态环境中存在的主要问题，即由人为活动引起的水土流失、森林资源减少、草馒质量下降及土壤退化和沙化等。从自然因素和人为因素两个方面分析了黑龙江省生态环境退化的成因，并对黑龙江省生态保护工作要点进行了探讨。