速生杨不同修枝强度对胸径和树高生长量的影响

基于速生杨中黑防经营技术,进行了不同修枝强度对胸径和树高生长量的影响试验,结果表明：采用中度修枝强度有利于提高速生杨胸径生长量和立木蓄积量,而弱度修枝和重度修枝强度与中度修枝相比,无论树高还是胸径,均相对减少,冠幅随修枝强度的变大而减小,冠幅面积依次为未修枝>轻度修枝>中度修枝>重度修枝。掌握适宜的修枝强度在提高树干圆满度的同时,能够提高立木蓄积量及优质木材率。     

Characterization of Aerococcus viridans isolated from milk samples from cows with mastitis and manure samples

Thirty-eight Aerococcus viridans isolates were obtained from milk from 478 cows with clinical mastitis in a farm during the periods between November 2011 and February 2012, and between December 2012 and March 2013. Additional isolates were obtained from processed manure (a mixture of composted manure, straw and hydrated lime) and bedding materials. The processed manure was later used to cover the floor of the stalls in barns as bedding materials. The temperatures recorded in the composted and processed manure were not as high as those generally observed during satisfactory composting. To reveal the association of A. viridans in manure-related products with intramammary infection in cows, isolates were characterized by their DNA fragment patterns as determined by pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility testing. Isolates obtained from milk, processed manure and bedding materials had identical DNA fragment patterns. Antimicrobial susceptibilities were determined for 29 isolates from milk, processed manure and bedding materials. Of these, 26 (89.7%) were resistant to clindamycin, whereas virtually all the isolates were susceptible to 12 other antimicrobials including cefalosporins that have been used to treat bovine mastitis in Japan. In vitro, three A. viridans isolates from milk and an isolate from processed manure survived for 3 hr in Good’s buffer (pH 9) at high temperature (50°C). The results suggest that the processed manure and bedding materials in this farm were possible sources of A. viridans that caused infection in the cows with mastitis.     

营林防火的理论和实践

对几种营林措施降低森林火险性进行了理论分析和实践探索 (设计 ) ,因为营林工作贯穿森林的一生 ,营林的内容广泛且都与森林火险性有联系 ,设计中提到的间伐、修枝是已经普遍开展的营林内容 ,营林效益显著 ,防火效果明显。补植加密、镶边造林是对疏林、块状林进行的 ,既增加生产力 ,又兼得防火效益的营林措施。为十三陵旅游胜地森林公园的需要 ,文章对“金字塔造型”、“群状间伐造型”和“一树一库”做了设计和说明     

洞庭湖洲滩杨树人工林对钉螺孳生的影响

为探讨修枝强度、林农间种、异龄林等因素对洞庭湖洲滩钉螺孳生的影响,对拐棍洲有螺滩地杨树人工林的螺情分布进行了长期定点调查。结果表明:4年生杨树林,修枝次年林分内的活螺框出现率、活螺密度均低于修枝当年,其中1/3修枝强度次年林分活螺框出现率、活螺密度较修枝当年分别降低了68.00%和80.80%。林农间种的杨树林较翻耕不种和不耕不种的杨树林抑螺效应显著,翻耕而不间种的杨树林,活螺框出现率与不耕不种的1年生杨树林一样,但活螺密度却较不耕不种下降了47.20%。异龄林营造后,活螺密度大致呈下降趋势,营造后的第2、3、4年时活螺框出现率、活螺密度分布较营造当年下降73.33%、50.00%、77.67%和75.96%、43.94%、83.85%。林分郁闭后,全面翻垦的林分活螺框出现率、活螺密度均比不翻垦的林分低直至趋于零。除了高程(32.64m)较高的林分外,其他高程全耕不种林分内活螺框出现率、活螺密度均低于全垦间种。     

Co-application of compost or inorganic NPK fertilizer with biochar influences soil quality,grain yield and net income of rice

Most agricultural soils in sub-Saharan Africa are degraded, compromising the grain yield of rice and farmers return on investment. A 3-year field study was undertaken to explore the effect of the application of compost or inorganic NPK fertilizer applied alone or in combination with biochar on soil quality, grain yield of rice and net income. The five treatments were laid out using a randomized complete block design with four replications. The treatments were applied to supply approximately 75 kg N ha^–1. The best fertilizer input was compost+biochar which resulted in the greatest improvement in soil physico-chemical properties by reducing bulk density and increasing porosity and moisture retention, organic matter content, percent nitrogen, available phosphorus and cation exchange capacity. Apart from treatment with inorganic fertilizer alone, treated soils showed a decrease in pH. Bacterial and fungal counts and basal respiration decreased in soils in the following order: compost+biochar>compost only>inorganic NPK fertilizer+biochar>inorganic NPK fertilizer>control. The increase in pooled grain yield and net income in response to treatment followed the order: compost+biochar>NPK+biochar>NPK>compost>control. The findings suggest that the use of compost or NPK alone might improve soil quality and increase grain yield and net income, but it is greatly recommended to co-apply these fertilisers with biochar.     

莫桑比克9个腰果品系截干复壮效果研究

以9个品系的13龄腰果树为对象,采用主枝截干更新的方法,研究不同腰果品系的截干复壮效果。试验结果表明：不同腰果品系截干复壮效果有所差异;品系2.4PA、11.7PA、2.3PA、7.10PA截干后的复壮效果较好,11.9PA复壮效果一般,16.3BG、12.9PA、1.12PA、5.12PA复壮效果较差;品系2.3PA截干1年后的结果量最多,单株结果量达160.0个,接下来依次为11.7PA、16.3BG、12.9PA、7.10PA、1.12PA、5.12PA、11.9PA和2.4PA。     

蔬菜废弃有机物无害化处理及再利用技术研究

以丝瓜藤为腐熟原料,通过添加EM菌剂和秸秆腐熟剂进行腐熟试验,研究腐熟剂处理后腐熟物的无害化处理以及肥料化再利用技术。结果表明:腐熟剂处理后的废弃有机物表观性状、温度、pH值可达到无害化处理的标准;还田后可提高土壤肥力和改善土壤结构,为废弃物的资源转化提供了有效途径。     

道路绿化树木修剪及剩余物制片联合机的研究与分析

通过对国内外树木修剪机械及修剪后的剩余物处理现状研究,提出一种道路绿化树木修剪及剩余物制片联合机,并对其经济效益进行了分析。该机实现了路旁树木的修剪及剩余物现场处理。     

造林密度和修枝对‘欧美107杨’生长量的影响

以3种造林密度‘欧美107杨’为研究对象,通过测定不同年份胸径、树高、枝下高等,来分析造林密度及修枝对‘欧美107杨’生长量的影响.结果表明,‘欧美107杨’胸径和单株材积生长量随着造林密度的增大而减小,即3种造林密度‘欧美107杨’2a胸径和单株材积生长量由高到低依次为株行距3m×12m、5m×6m、3m×6m,而树高生长量变化趋势正好相反.修枝在一定程度上能促进树高生长和提高枝下高,有利于提高杨树木材质量.     

添加烟草废弃物对堆肥腐熟度及抑制线虫作用的影响

以鸡粪和小麦秸秆为堆肥原料,在C/N为25与含水率为60%的条件下采用静态好氧堆肥工艺,研究了不添加烟草废弃物(CK)和在初始期(A)、高温期(B)、一次发酵完成(C)和陈化腐熟后(D)添加1.5%(干重质量比)烟草废弃物对堆体发酵温度、总碳(TC)、发芽率指数(GI)和根结线虫校正死亡率的影响。结果表明:添加烟草废弃物会降低堆肥发酵过程的温度,影响微生物对有机物料的分解,不利于堆肥物料的快速腐熟。CK处理的GI值在19d时已超过腐熟度标准80%的要求,而添加烟草的处理A、B和C的GI值在19d时仍低于80%;在处理45d时处理CK、A、B、C和D的GI值分别为102.6%、95.6%、85.8%、83.4%和70.4%;这表明烟草废弃物对植物生长具有一定的抑制作用。烟草废弃物和处理C与D堆肥产品浸出液的线虫校正致死率都达到了100%;而处理CK、A和B堆肥产品浸出液的线虫校正致死率依次为44.4%、28.2%和70.0%;这表明烟草废弃物经过发酵的时间越长,对线虫的抑制效果就越差;在堆肥一次发酵完成后添加烟草废弃物,不但可避免其对堆肥进程和植物生长的不利影响,而且经过陈化腐熟后仍能保持对根结线虫的抑制作用。