Achieving food and nutritional security through agroforestry: a case of <Emphasis Type="Italic">Faidherbia albida</Emphasis> in sub-Saharan Africa

Faidherbia albida is an ideal agroforestry tree commonly intercropped with annual crops like millet and groundnuts in the dry and densely populated areas of Africa. With its peculiar reverse phenology, it makes growth demands at a different time from that of crops. In addition, it deposits great amount of organic fertilizer on food crops. Leaves entering soils are comparable to fertilization of almost 50 t·ha 1 ·year 1 of manure in dense stands of 50 large trees per ha. These nutrients help maximize agricultural production and reduce the need for a fallow period on poorer soils. Research has shown that millet grown under F. albida yielded 2.5 and 3.4 fold increases in grain and protein, respectively. Animals eat pods which contain mean amounts of crude protein of 20.63% and carbohydrate of 40.1% in seeds. Moreover, the continued existence of F. albida in agroforestry parklands as in Ethiopia and Mali signifies the success of traditional conservation measures. Modern scientists have also developed much interest in the role of agroforestry in maintaining long-term biological balance between agriculture and livestock production systems. To ensure food security, which still remains a major challenge in sub-Saharan Africa, and concurrently minimize environmental degradation, promotion of agroforestry that specifically involves indigenous trees is crucial. We discuss the prospective role of F. albida in alleviating poverty while simultaneously protecting the environment from factors associated with, for example, deforestation and loss of biodiversity. The overall aim is to promote wide-scale adoption of F. albida as a valuable tree crop in farming systems, particularly in those areas where it remains unexploited.     

基于空间插值分析法的棉花生长适宜性评价

利用GIS软件提供的空间插值法分析处理南阳市宛城区离散的土壤养分监测点数据,将点状数据插值为面状数据,并进行了棉花生长适宜性评价,此次工作结果不但对指导宛城区棉花的生产有实际意义,而且此次的方法也可为其它工作提供一些借鉴。     

几种造纸用丛生竹秆节育苗试验

在福建省邵武市对椽竹、孝顺竹、坭竹等几种造纸用丛生竹进行秆节育苗试验表明，用平埋方法育苗显著优于斜埋和直插，竹蔸平埋效果更佳；不同竹种秆节育苗成活率存在明显差异；不同年龄的秆节育苗成活率在不同竹种间表现不同；不同育苗时间（３月或５月）的成活率差异不显著。竹秆不同粗细、不同部位、单节段或双节段育苗对比试验，结果以细秆（胸径２．５ｃｍ）、上部节段、双节段育苗成活率较粗秆（胸径４．６ｃｍ）、下部节段、单节段的为高。椽竹秆节径用不同激素处理后，处理间成苗率差异显著，以２，４－Ｄ２０ｍｇ／ｋｇ处理５ｈ和硼酸２０ｍｇ／ｋｇ处理２４ｈ的效果最佳。几种造纸用丛生竹秆节育苗试验＊张文燕周道三马乃训叶长青曹德友张华明     

皖西南春棉田主要害虫和天敌种群时序动态格局

为探索直播春棉田害虫与其天敌之间的相互作用和竞争共存机制,采用直接观察法,系统研究了棉田主要害虫和天敌种群的时间动态变化,及其生态位宽度和生态位重叠值。研究结果表明,在直播春棉的不同生育期,棉田害虫和天敌的优势种不同。主要害虫和天敌的发生高峰期多集中在6—7月,而棉蚜高峰期在5月下旬,棉叶蝉高峰期在9月下旬。不同种群的时间生态位不同,害虫中棉盲蝽的生态位宽度最大,其次是棉铃虫,棉叶蝉和棉叶螨的生态位宽度较小;天敌中蜘蛛类天敌的生态位宽度最大,其次是小花蝽,黑襟毛瓢虫的生态位宽度最小。而黑襟毛瓢虫和瓢虫类天敌与棉蚜、棉叶螨生态位重叠度较大。因此,皖西南棉区直播春棉田可利用瓢虫类天敌抑制棉蚜和棉叶螨的危害,保护并利用好蜘蛛类天敌,需重点防治棉盲蝽和棉铃虫。     

五种昆虫生长调节剂对韭菜迟眼蕈蚊的致毒作用

为明确昆虫生长调节剂对韭菜迟眼蕈蚊幼虫的毒力差异、作用特点和田间控制效果,采用药液定量滴加法比较了5种昆虫生长调节剂对其不同龄期幼虫的毒力、LC50对4龄幼虫生长发育和繁殖的影响,以及药剂致毒的温度效应和盆栽防效。结果表明:5种昆虫生长调节剂对韭菜迟眼蕈蚊2龄和4龄幼虫的毒力均以虱螨脲最高,LC50分别为0.173 mg/L和0.295 mg/L,氟铃脲和氟啶脲次之,均高于对照药剂辛硫磷;而吡丙醚和灭蝇胺低于辛硫磷。5种昆虫生长调节剂以LC50处理4龄幼虫后,虱螨脲、氟铃脲和氟啶脲对其存活幼虫后续发育历期、成虫羽化率和繁殖力的影响较大,尤其是单雌产卵量较清水对照分别降低72.6%、57.8%和58.1%;灭蝇胺也可使成虫产卵量降低;吡丙醚可引起卵孵化率下降。该类药剂对其幼虫的毒力基本不受环境温度的影响;虱螨脲、氟铃脲和氟啶脲7.5、15 g a.i./667 m2处理对当代4龄幼虫的防效较低,但对下一代幼虫的防效可达93%以上;虱螨脲、氟铃脲和灭蝇胺与新烟碱类的噻虫胺混用,可显著提高药剂的速效性,且持续控制作用好。     

海产品中副溶血弧菌的分离与鉴定

副溶血弧菌（Vibrio Paraaemolyticus)是一种致病性嗜盐菌，常引起人类食物中毒，通过对四种不同海产品的检测，发现该菌检出率很高，其中，海虾中的检出率高达90％，海产鱼为70％，贝类为60％，海蟹为40％，平均检出率为65％，动物试验证实，该菌致病性较强。     

杂交肉牛不同年龄,营养水平的肥育效果研究

利用利木赞与本地牛杂交一代7～8月龄公犊12头，10～11月龄公牛12头，供给日增重0．9千克，1．2千克和1．5千克营养水平的日粮，经120天肥育，结果表明：7～8月龄和10～11月龄高营养水平组平均日增重分别为1．274±0．06千克和1．340±0．15千克；7～8月龄组对不同营养水平敏感，各组间差异极显著（P＜0．01）；产肉性能以高营养水平组最好，屠宰率62．4％，净肉率52．98％，眼肌面积91平方厘米。     

不同郁闭度林茶复合模式对茶树光合日变化的影响

茶叶的产量和品质与生长环境关系非常密切,为探明林分不同郁闭度对茶树光合日变化的影响,本研究以不同郁闭度的栾树（Koelreuteria paniculata）-茶（Camellia sinensis）复合系统中茶树为材料,纯茶园为对照（CK）,利用便携式LI-6400光合作用测定仪研究茶树分别在0.3（T1）、0.6（T2）和0.9（T3）郁闭度条件下的光合作用参数日变化。结果表明：随郁闭度增加,茶树光合有效辐射（PAR）和叶片温度（Tl）日均值和差值呈递减趋势,日变化呈单峰曲线;茶树净光合速率（Pn）日均值随郁闭度增加呈递减趋势,均表现双峰型曲线;CK和T1的蒸腾速率（Tr）和气孔导度（Gs）日变化午间受到明显的抑制且呈双峰曲线,T2和T3呈单峰型曲线。     

2014年春季内蒙古2次大风降雪寒潮过程分析

对于环流特征相似的寒潮过程,其爆发的方式、产生的天气和影响的区域基本相似,但个别寒潮过程却存在较大的差异,造成预报上的误判。针对此类特例,基于常规气象观测资料,自动站观测资料和NCEP逐6 h 1°×1°再分析资料,应用天气学分析和诊断方法,对2014年4月24日（过程1）和5月1日（过程2）2次寒潮天气过程的环流、系统和爆发的动力、热力学机制等进行对比分析。结果表明：2次过程北半球中高纬500 hPa环流形势均具有两脊一槽的环流特征。寒潮区域升温明显,前期平均温度分别比历史同期偏高1.0~7.3℃和0.1~10.7℃,500 hPa冷槽和强锋区均在新疆北部堆积、爆发南侵;2次过程在爆发方式和成因上存在着较大的差异,过程1中促使寒潮爆发流场为横槽转竖,槽前疏散结构和正涡度平流使低槽切断出低涡并东南移,冷平流中心移至槽前,横槽转竖寒潮爆发。过程2为低槽东移,冷槽移过阿尔泰山和蒙古高原加深东移,冷空气入侵内蒙古,寒潮爆发。虽然2次过程均造成了全区范围的强降温,但由于上述影响方式和成因的不同,使得大风、沙尘暴和降水呈现出不同的影响特点。寒潮过程中大风和沙尘暴的分布除与冷平流有关外,还与高空动量下传的地点和时间密切相关,对于寒潮过程中的降水而言,低层的温度层结及其水汽输送特点,决定了不同地区的相态变化和降水的量级。通过关注环流相似寒潮过程中的爆发方式和动力过程,对于正确预报寒潮天气造成的不同地区的降温、大风、沙尘和降水具有很好的借鉴意义。     

蔬菜穴盘苗自动精确移栽组合式取苗机构设计与测试

Precision planting is one key point of precision agriculture.A doorframe type swing seedling pick-up device for the automatic precise field transplanter was designed and tested in a laboratory.The seedling device could automatically extract seedlings from growing trays, transfer them, and release them into the planting unit where they were to be precisely transplanted into the ground.It consisted of a path manipulator and two grippers.The path manipulator for seedling extraction was constructed with creative design of Ⅱ-type mechanism combination in series.It consisted of an oscillating guide linkage mechanism and a grooved globoidal cam mechanism.According to the planned seedling pick-up trajectory, the design of the path manipulator for seedling extraction was finished with a set of the closed loop vector equation.The gripper was a pincette-type mechanism using the pick-up pins to penetrate into the root mass for seedling extraction.It consisted of multiple pick-up pins, U-type pull rod, shaft, stop block, compression spring and frame.The mechanical dimensions of the gripper were determined by the tray size and plant characteristic with a set of rectangular equations and the boundary constraint conditions.The final gripper was developed on the basis of cultural practice for vegetable seedling in China.A prototype of the seedling pick-up device was constructed to examine whether its working efficacy was satisfactory or not.According to the analysis on the work process, the seedling pick-up device could precisely complete a work cycle of approaching, penetrating, extracting, transferring, erecting and discharging a seedling.Taking pepper seedlings, tomato seedlings and cucumber seedlings as the transplanting objects, the performance tests were conducted to evaluate the practicality and adaptability of the pick-up device.The laboratory evaluation showed that the pick-up device equipped with two grippers could extract 70 seedlings per minute with an average success ratio of 90.49%.The quality of extracting seedlings was satisfactory.