The role of agroforestry in the farming systems in Rwanda with special reference to the Bugesera-Gisaka-Migongo (BGM) region     

V. Balasubramanian  A. Egli 《Agroforestry Systems》1986,4(4):271-289

The Rwandan farmers, faced with a perpetual land shortage, have evolved certain intensive systems of organic agriculture. These systems, particularly the homestead (compound) farming, involve the combination of food, fodder and tree crops. to a certain extent these systems can satisfy the multiple needs of the subsistence farmers living under several risks and constraints. However, they cannot cope with the expanding food demand of the rapidly increasing population. Some multipurpose, low-input technologies and agroforestry approaches have been designed to improve the productivity of these traditional systems; these include inter/mixed cropping systems and rotations, alley cropping with leguminous trees and shrubs, use of planted fallow, planting tree legumes on anti-erosive lines, mixed farming,community forestry and woodlots, and tree planting on farm/field boundaries. The essential aspects of these technologies are briefly discussed.ISAR-IITA FSR PROJECT, B.P. 629, Kigali RwandaISAR-Swiss Intercooperation, c/o Forestry Department, B.P. 617, Butare, Rwanda  相似文献   

影响沥青路面开裂的因素分析   总被引：4，自引：0，他引：4  

窦大峣  杨民  张松涛 《森林工程》2003,19(3):56-57

本文对沥青路面开裂的原因进行了系统分析 ,并对沥青混合料低温抗裂性能的评价做了进一步的探讨  相似文献   

向日葵盘及其果胶主要组成的研究     

罗庆云 《林产化学与工业》1996,16(3):45-50

研究结果表明，向日葵盘组成复杂，初步测定出１０多种天然化合物，其果胶含量以海绵状肉质部位最高，锯齿形苞片部位最低。用气相色谱法分别测定了向日葵盘及其果胶中各种糖基的相对含量，发现它们都含有木糖、阿拉伯糖、甘露糖、半乳糖和葡萄糖等，向日葵盘中葡萄糖含量最高果胶中含半乳糖最多。向日葵盘用水预洗得到的水溶性果胶，其酯化度大于５０％，属于高酯果胶，其表观分子量为１７３４００，向日葵盘经一分别用稀无机酸及多  相似文献   

CaCl_2处理对奈李低温贮藏期生理生化的影响     

苏冬梅  谷文众  陈灿  邓江望 《中南林业科技大学学报(自然科学版)》2001,(2)

为了探明 Ca2 对奈李低温贮藏的保鲜效应 ,对奈李采用不同浓度的 Ca Cl2 溶液处理、聚乙烯薄膜袋包装、在低温 ( 5℃ )下贮藏 ,研究其生理生化变化情况 .结果表明 :采用质量分数为 0 .5 %～ 1.0 %的 Ca Cl2 溶液处理 ,对奈李的呼吸作用、Vc含量的降低、可溶性固性物的消耗、电导率和 POD(过氧化物酶 )活性的升高以及贮藏期的失水等均具有抑制作用 ,而用较高浓度的 Ca Cl2 ( 2 .0 %～ 6.0 % )溶液处理 ,则具有相反的作用 .  相似文献   

浅谈低温热水地板辐射供暖系统在实际运行中出现异常问题的因素和解决的方法     

岳胜利  王歌 《林业科技情报》2006,38(2):52-53

低温热水地板辐射采供暖系统在实际运行时常出现室内设计温度达不到和热力失调现象,现就结合几年中实际工作进行归纳和分析。  相似文献   

信阳板栗低产林综合改造技术的研究   总被引：1，自引：0，他引：1  

张琰 《河南林业科技》2003,23(3):5-6,11

信阳市板栗生产中普遍存在产量低,品质差问题,本文通过对板栗低产原因的分析,为开发板栗资源,提出了优质高产栽培的重要途径和措施。  相似文献   

不同贮藏方法对3种药用植物种子发芽率的影响   总被引：6，自引：0，他引：6  

唐秀光  秦淑英  宋珍  王文全  王君山 《河北林果研究》2001,16(2):133-135

为了保存药材种子的生活力 ,进行了不同贮藏方法的研究。试验采用 3种处理、 3次重复。结果表明 ,黄芪、桔梗和黄芩 3种药材种子以低温贮藏效果最好 ,贮藏 9个月后发芽率分别为 70 %、 82 %和 54% ,仍具有较高的播种品质。  相似文献   

混凝土挡土墙裂缝原因及防治办法     

赵云龙 《林业科技情报》2002,34(1):54-54

本文作者通过自己多年的工程施工实践,结合设计与施工中共同存在的问题及注意事项,总 结出了混凝土挡土墙裂缝产生的主要原因及防治方法。  相似文献   

麦秸半焦低温催化气化实验研究   总被引：2，自引：0，他引：2  

俞元元  肖军  沈来宏  杜玉照 《林产化学与工业》2015,35(1):113-120

以麦秸半焦为研究对象,比较麦秸半焦和酸洗麦秸半焦700℃下水蒸气气化实验,研究了麦秸灰分中碱金属含量、催化剂种类(K基、Ca基和Fe基)对气化过程的影响。实验结果表明,麦秸灰分中较高含量的碱金属K能够有效促进半焦气化的进行,使得在非催化条件下半焦的碳转化率达到63.4%,相比酸洗麦秸半焦提高了2.6倍。低温下碱金属K基催化剂对半焦气化的促进作用显著,在700℃和K/Al催化剂条件下H2产率和碳转化率分别达到118.60 mol/kg和98.5%,相较于Ca/Al、Fe/Al催化剂而言,H2产率分别提高了10.7%和20.5%,碳转化率提高了12.4%和31.0%;而Ca/Al及Fe/Al催化剂有利于水气变换反应的进行,可提高气化产物中H2体积分数,降低CO体积分数。综合考虑碳转化率、气体产率及气体组分含量等因素,在催化效果较好的K基催化剂中添加适量的Ca基催化剂有利于调节产气成分,从而进一步提纯获得富氢气体。  相似文献   

GROSS AND HISTOPATHOLOGIC CORRELATION OF LOW‐FIELD MAGNETIC RESONANCE IMAGING FINDINGS IN THE STIFLE OF ASYMPTOMATIC HORSES          下载免费PDF全文

Marcos P. Santos  Santiago D. Gutierrez‐Nibeyro  Alexia L. McKnight  Kuldeep Singh 《Veterinary radiology & ultrasound》2015,56(4):407-416

With the recent introduction of a 0.25T rotating MRI system, clinical evaluation of the equine stifle joint is now possible in the average equine athlete. A recent publication described common abnormalities of horses with stifle lameness detected with a low‐field MRI system; however, postmortem corroboration of the lesions detected was not possible. Therefore, our objective was to compare postmortem findings with low‐field MRI findings in equine cadaver stifle joints. Ten fresh cadaver stifle joints from horses without clinical signs of stifle disease were evaluated using low‐field MRI, gross dissection, and histopathology. In eight stifles, either the lateral or medial cranial meniscotibial ligament had an irregular shape, fiber separation, or moderate abnormal signal intensity (SI) on all sequences. In five stifles, the medial femoral condyle had articular cartilage fibrillation with or without an osteochondral defect over the weight bearing surface of the medial femoral condyle. All stifles had abnormal SI on all sequences within the patellar ligaments that corresponded with adipose tissue infiltrating between the collagen bundles. Other abnormalities identified included articular cartilage fibrillation of the tibial condyles in three stifles, and articular cartilage fibrillation with chondral defects in the patella in three stifles. All abnormalities detected with low‐field MRI were corroborated by gross dissection. Findings from the current study supported the use of low‐field MRI for detection of stifle joint lesions in horses and demonstrated that some stifle joint pathologies may be subclinical in horses.  相似文献