我国热区疫霉种的分布、疫病及其防治研究进展

综述了我国热带地区疫霉种类及其引起的植物病害,并总结了疫病的防治措施,最后对疫病防治的新策略进行了展望。     

多项目管理理论在水库移民后扶项目中的初步研究

结合水库移民工作实践经验,构建了后扶项目多项目管理组织机构并初步分析了多项目管理在后扶项目管理中开展方法.     

黑龙江农垦齐齐哈尔管理局奶牛养殖小区饲养经营模式及效益的探析

对农垦齐齐哈尔管理局奶牛养殖小区的饲养经营模式及效益进行了调查,分析了奶牛小区建设给奶牛群带来的主要变化。通过分析不同模式奶牛小区生产经营状况,确定适合该地区奶牛业发展的奶牛小区经营模式。     

根区滴灌对干旱山地苹果树生长发育和结实的影响

根区滴灌是将雨水促渗管与传统滴灌相结合而组装集成的一项节水灌溉新技术。为了探讨根区滴灌在山地果园的应用效果,为山地果园的栽培管理提供依据,本文以陕北米脂县6 a生山地红富士苹果树为研究对象,以世界公认的最佳苹果优生区洛川县的降雨量和土壤贮水量为灌水依据,分析了不同灌溉方式对苹果树萌芽、坐果、枝叶生长、果实发育和水分利用效率的影响,以及山地果园土壤水分达到优生区标准后与优生区苹果树生长结果的差异。结果表明,采用根区滴灌能有效提高苹果树的萌芽率和坐果率,萌芽率比传统滴灌提高了2.14%~2.76%,坐果率比传统滴灌提高了0.80%~1.42%;能有效促进苹果树新稍和叶片的生长,新稍长度比传统滴灌提高了1.44%~4.94%,百叶鲜质量比传统滴灌提高了2.13%~4.16%;能显著促进苹果树果实的生长,单果重比传统滴灌增大了7.05~14.99 g,优果率比传统滴灌提高了9.4%~14.7%;能显著提高水分利用效率,灌水量比传统滴灌节约了8.09%,水分利用效率比传统滴灌提高了10.62%~15.30%。可见,根区滴灌技术在陕北黄土丘陵区山地苹果生产中具有广阔的应用效果,但是,单纯依靠人为限量补水,山地苹果还不能达到优生区的生产水平。     

某水库建设项目地质灾害危险性评估

通过野外调查、室内分析研究了评估区的地质环境条件,主要包括环境地质、水文地质和工程地质;结合建设项目可行性研究报告、岩土工程勘察报告,对某水库建设项目地质灾害危险性进行了现状评估、预测评估以及综合性分区评估;对拟建场地进行了适宜性评价,并提出了地质灾害防治措施。     

三岔子林区黄檗野生种群资源状况的调查与分析

以吉林省三岔子林业局不同林龄的林分为对象,调查与分析黄檗野生种群的资源状况,结果表明:单位面积活立木平均株数在幼龄林林分中占12.3%,在中龄林中占3.8%,在成过熟林中占2.6%,3个龄组林分的平均株数比例为6.2%;单位面积活立木平均蓄积在幼龄林林分中占7.3%,在中龄林中占2.4%,在成过熟林中占1.3%,3个龄组林分的平均蓄积比例为3.7%。     

Nutrient availability and corn growth in a poultry litter biochar‐amended loam soil in a greenhouse experiment

Nutrient‐rich biochar produced from animal wastes, such as poultry litter, may increase plant growth and nutrient uptake although the role of direct and indirect mechanisms, such as stimulation of the activity of mycorrhizal fungi and plant infection, remains unclear. The effects of poultry litter biochar in combination with fertilizer on mycorrhizal infection, soil nutrient availability and corn (Zea mays L.) growth were investigated by growing corn in a loam soil in a greenhouse with biochar (0, 5 and 10 Mg/ha) and nitrogen (N) and phosphorus (P) fertilizer (0, half and full rates). Biochar did not affect microbial biomass C or N, mycorrhizal infection, or alkaline phosphomonoesterase activities, but acid phosphomonoesterase activities, water‐soluble P, Mehlich‐3 Mg, plant height, aboveground and root biomass, and root diameter were greater with 10 Mg/ha than with no biochar. Root length, volume, root tips and surface area were greatest in the fully fertilized soil receiving 10 Mg/ha biochar compared to all other treatments. The 10 Mg/ha biochar application may have improved plant access to soil nutrients by promoting plant growth and root structural features, rather than by enhancing mycorrhizal infection rates.     

白石水库水源富营养化评价及供水可靠性分析

本文在对白石水库水源富营养化进行评价的基础上,对水库供水可靠性进行了分析.从现状水质评价结果看,白石水库的水质满足《地表水环境质量标准》(GB 3838-2002)中的Ⅲ类用水水质要求,可以作为集中式生活饮用水水源地和工业用水水源地.经过水量调节计算,可知白石水库供水水质是可靠的.     

Soil organic carbon stock variability in the Northern Gangetic Plains of India: interaction between agro‐ecological characteristics and cropping systems

Soil organic carbon (SOC) content and its spatial distribution in the Northern Gangetic Plain (NGP) Zone of India were determined to establish the cause–effect relationship between agro‐ecological characteristics, prevailing crop management practices and SOC stock. Area Spread Index (ASI) approach was used to collect soil samples from the NGP areas supporting predominant cropping systems. Exponential ordinary kriging was found most suitable geo‐statistical model for developing SOC surface maps of the NGP. Predicted surface maps indicated that 43.7% area of NGP had 0.5–0.6% SOC, while the rest of the area was equally distributed with high (0.61–0.75%) and low (< 0.5%) SOC content levels. Averaged across cropping systems, maximum SOC content was recorded in Bhabar and Tarai Zone (BTZ), followed by Central Plain Zone (CPZ), Mid‐Western Plain Zone (MWPZ), Western Plain Zone (WPZ) and South‐Western Plain Zone (SWPZ) of the NGP. The SOC stock was above the optimum threshold (> 12.5 Mg/ha) in 97.8, 57.6 and 46.4% areas of BTZ, CPZ and MWPZ, respectively. Only 9.8 and 0.4% area of WPZ and SWPZ, respectively, had SOC stock above the threshold value. The variation in SOC stock was attributed largely to carbon addition through recycling of organic sources, cropping systems, tillage intensity, crop or residue cover and land‐use efficiency, nutrient‐use pattern, soil texture and prevailing ecosystem. Adoption of conservation agriculture, balanced use of nutrients, inclusion of legumes in cropping systems and agro‐forestry were suggested for enhancing SOC stock in the region.