彰武甜菜生产与气象条件关系研究

彰武县自70年代初引种甜菜,至今已有20多年的栽培历史,目前甜菜已成为本县的一种重要经济作物,糖的产量约占全省的33％。由于甜菜生产受到种子、土壤、肥力、气候等诸多因素的不利影响,其产量、含糖率低而不稳。根据资料分析气象因子往往成为制约甜菜生产的重要因素,因此有必要对彰武甜菜生产与气象条件关系进行研究探讨。     

利用黔江气候资源 大力开发“两冬”

通过黔江地区的气候分析,得了该区夏旱少,尤其是适宜水稻移载是本区降水量最多的时期因此可利用这一资源优势,大力开发“两冬”,大放干冬水田,大办小春,使黔江小麦面积扩大近１倍,小麦粮食由的来仅占１／５提高到１／３,成为小麦、玉米、水稻三分天下的粮食生产局。     

安宁河流域西昌段以南溪区可大面积种植杂交稻

以汕优６３为代表的杂交稻在水利条件好的、采用保温育秧技术、培育多蘖壮秧、适时播种裁插,并且齐穗期安排在８月中旬前并加强栽培管理的稻区,即能最大程度地避免风险而获高产。     

单轴压力下岩石破裂的初步研究

用几种不同加载方式对岩石样品进行了单轴压力实验。以恒定应变率(约为10^-5)对样品加载时,岩石的破裂过程大致可分成四个阶段:孔隙压缩阶段、弹性变形阶段、体积膨胀阶段和临震阶级。后二个阶段显著的特点是岩石开始表现出非弹性的体积应变并在主破裂前急剧增大,它与微破裂累积总数二者存在着同步的变化。在重复加载时,发现岩石的微破裂过程具有不可逆的性质,这种现象似乎可以用来说明同一地区短期内发生的两次地震的地震序列的不同,指出运用历史地震资料时应注意该地区应力变化的历史情况。     

土地资源集约利用的科学内涵

当前,我国用地需求已在很大程度上难以有效满足经济社会发展之需求,土地资源“瓶颈”效应日益凸显。随着当前和今后一段时间,我国陆续进入城镇化、工业化加速发展时期和人口高峰期,土地资源将变得更为紧缺,人地矛盾也将更为尖锐。如果继续沿袭既往的土地利用方式,土地资源固有的支撑和保障经济社会持续发展的功能将难以维系,我国经济发展也将陷入土地利用的“马尔萨斯陷阱”。在土地后备资源有限而“开源”前景并不乐观情况下,我国土地利用亟需更新观念,     

世界自然基金会呼吁改变海洋捕捞方式

近日世界自然基金会专家在接受德国媒体采访时表示,人类目前在海洋大规模捕鱼的行为已经导致了许多不能带来经济效益的鱼类及其他动物死亡,许多     

青海省近年土地利用变化趋势分析

青海省因气候、海拔等自然因素影响,人口较少,经济建设产生的土地利用虽在近几年有所改观,但尚未达到全国平均水平。"十一五"期间,努力实现青海省经济体制和经济增长方式的根本转变,保持经济社会可持续发展,全面推进现代化建设,离不开土地这一根     

电子地图产业发展刍议

电子地图（Electronic Map），是一种基于计算机技术与综合数字制图理论，以数字方式存储和查阅的可视化地图。随着下一代通讯网络的建立，以及移动互联网和物联网的发展，我们将迎来大众化电子地图应用的时代。     

Improving Indigenous Technologies for Sustainable Land Use in Northern Mountainous Areas of Vietnam

More than 30 ethnic groups are now living in northern mountainous regions, Vietnam, mainly relying on shifting cultivation with the fallow period being shortened from time to time. Naturally, soil fertility reduces from cycle to cycle, entailing the reduction of productivity. Large areas of moderately sloping lands suitable for upland agriculture have become bare after many cultivation-fallow cycles. The soils there have been severely degraded with more toxicity, low porosity, low water retention capacity and poor floral diversity. Normally, these lands cannot be used for food crop cultivation. So farmers in uplands have to rely on slash-and-burn practices for their livelihood. As there is no more forest with good soil in medium slopes, farmers go to cut forests in watershed, high slope lands and old forests up to the mountains‘ top. There are ecologically and environmentally very sensitive areas, so their destruction will inevitably cause hazardous consequences in the whole basin. Meanwhile,cultivation in these areas has low economic efficiency and sustainability because the crop yield may decrease very fast due to severe erosion as the higher the slope, the more serious erosion. Consequently living standards of highland farmers remain low and unstable. Sustainable farming on these lands in the perspective of a seriously deteriorated ecology and environmental is not an easy task. There have been many projects trying to help mountainous farmers get out of their vicious circle. However, due to different reasons, the results gained are low, and in some cases,things ceased to move after the projects phased out. During past few years, based on the farmer experiences, the Vietnam Agricultural Science Institute has cooperated with local and international partners to implement different projects in order to solve the problems by developing simple, easy and cheap cultivation technologies, which can be accepted and applied by local poor farmers for sustainable agricultural production. The first results of our activities offered good opportunities for sustain food production, improve soil health, recharge of aquifers,and enhanced household income for better rural lively hoods in the upland eco-regions of northern Vietnam.