小菜蛾为害不同生育期秋甘蓝对产量的影响及经济阈值研究

采用笼罩法测定了小菜蛾在秋甘蓝不同生育期为害造成的产量损失,建立了产量损失率与小菜蛾虫口密度的回归关系式。结果表明,在秋甘蓝苗期、莲座期、结球始期和结球中后期秋甘蓝损失率(y)与小菜蛾虫口密度(x)关系式分别为:y=9.480 6x-2.586 2,y=3.621 8x-0.790 2,y=-0.210 7x2+6.698 1x-1.906 5和y=0.081 1x2-0.147 9x+0.405 4。根据经济阈值模型,秋甘蓝不同生育阶段的小菜蛾幼虫经济阈值分别为苗期0.54头/株,莲座期0.91头/株,结球始期0.67头/株,结球中后期6.08头/株。该研究为秋甘蓝小菜蛾的防治策略和经济阈值的确定提供了科学依据。     

美国引进甜玉米品种的性状分析和评估

对从美国引进的11个温带品种进行了植株性状、穗部性状、产量及品质性状的分析和评估,以期筛选出适宜广东乃至华南地区栽培的温带品种.结果发现,引进的美国种皆为早熟品种,株高较矮、穗位较低、植株整齐度好、鲜穗较小(250～350 g)、产量较低.但是鲜苞的品质很好,特别是CSAYP6-225,其色泽、口感、甜度、籽粒深度、排列都较好,产量中等,适合鲜食和加工.     

流溪河国家森林公园森林生态系统服务功能间接价值评估

从森林生态系统的效益出发,选取涵养水源、调节气候、净化环境、土壤保持、固碳释氧、维持生物多样性和医疗保健等因子,采用市场价值法、影子价格法、机会成本法等多种手段对流溪河国家森林公园的森林生态系统服务功能的间接经济价值进行估算.结果表明.该森林公园每年的总生态服务价值约为2.18亿元.     

Cost analysis of sand barriers in desertified regions based on the land grid division model

Sand barriers are the most widely used mechanical implements for wind-blown sand control and desertification prevention. However, there is no standard quantitative cost analysis of the sizes and materials required for sand barriers. In this study, based on the original land grid division model for optimal resource utilization, we calculated the total side lengths of square and regular hexagonal sand barriers with the sizes of 1.0 m×1.0 m, 2.0 m×2.0 m, and 3.0 m×3.0 m in a desertified region of t...     

不同施肥处理对果蔗产量、外观品质及经济效益的影响

在广州市番禺区以当地习惯施肥为对照,探讨了不同施肥处理对果蔗产量、外观品质以及经济效益的影响,结果表明:与对照相比,采用氮磷钾配比为1:0.3～0.4:0.8～0.9、每667 m2施氮约46 kg的施肥方法,果蔗的株高、茎粗、有效茎数、单茎重、节数、平均节长以及商品蔗长均有不同程度的增加,果蔗的外观品质得到明显改善,且肥料用量减少、用肥成本降低,经济效益增加。     

基于省域数据的我国耕地非农化与经济发展研究

土地利用与社会经济活动关系密切。耕地作为土地的精华,面积变化与经济发展之间呈现出显著的规律性。通过分析我国经济成熟区、经济成长区和经济欠发达区经济差异特征的基础上,以1999年～2002年耕地面积统计数据为基础,采用相对指标(耕地减少率、耕地非农化率)和绝对指标(耕地建设占用总量和人均占用量)考察耕地减少状况,然后将各经济区域与耕地减少状况进行空间相关分析,结果表明,耕地减少率与区域经济发展水平相关性不显著,而耕地非农化率与经济发展之间存在着良好的相关关系,经济成熟区的耕地非农化率最高;耕地建设占用总量和人均占用量也表现出经济成熟区>经济成长区>经济欠发达区的特点。耕地建设占用程度与经济发展水平呈正向变化趋势。建立土地优化配置机制、推进产业结构升级代换是实现耕地非农化库兹涅茨曲线转化的关键措施。     

三角帆蚌金色品系生长性状遗传参数及基因型与环境互作效应分析

为培育出产金色珍珠的三角帆蚌Hyriopsis cumingii良种,并为三角帆蚌金色品系生长性状及产珠性能遗传改良提供理论依据,收集金色内壳色的三角帆蚌,经繁育共获得41个全同胞家系(F1～F41),分别在浙江武义和上海崇明两地养殖,在5月龄和17月龄时,分别测量两地各家系三角帆蚌壳长、壳高、壳宽和体质量4个生长性状...     

膨化血粉饲喂生长犬的效果试验

选择健康的2月龄生长犬40只，随机分为3个试验组(A，B，C)和1个对照组(D)，试验组分别饲喂添加5％，10％和15％膨化血粉的复合饲料，对照组饲喂添加8％鱼粉的复合饲料，进行30d饲哏试验。试验结果表明：A，B，C组与时照组相比日增重分别提高18．97％，2．17％和-13．55％；肉料比降低了19．62％，6．19％和-7．69％。     

TRANSFORMATION OF AGRICULTURE ON THE LOESS PLATEAU OF CHINA TOWARD GREEN DEVELOPMENT

● Agriculture on Loess Plateau has transformed from food shortage to green development. ● Terracing and check-dams are the key engineering measures to increase crop yields. ● Agronomic measures and policy support greatly increased crop production. ● Increasing non-agricultural income is a key part of increasing farmers’ income. ● Grain for Green Program had an overwhelming advantage in protecting environment. Loess Plateau of China is a typical dryland agricultural area. Agriculture there has transformed from food shortage toward green development over the past seven decades, and has achieved world-renowned achievements. During 1950–1980, the population increased from 42 to 77 million, increasing grain production to meet food demand of rapid population growth was the greatest challenge. Engineering measures such as terracing and check-dam were the crucial strategies to increase crop production. From 1981 to 2000, most of agronomic measures played a key role in increasing crops yield, and a series of policy support has benefited millions of smallholders. As expected, these measures and policies greatly increased crop production and basically achieved food security; but, low per capita GDP (only about 620 USD in 2000) was still a big challenge. During 2001–2015, the increase in agricultural and non-agricultural income together supported the increase in farmer income to 5781 USD·yr^–1. Intensive agriculture that relies heavily on chemicals increased crop productivity by 56%. Steadfast policy support such as “Grain for Green Program” had an overwhelming advantage in protecting the natural ecological environment. In the new era, the integration of science and technology innovations, policy support and positive societal factors will be the golden key to further improve food production, protect environment, and increase smallholder income.     

奶牛育种中关注的新性状

各国奶牛群体的选育目标建立之后,选育目标一直在不断发展,选择指数中性状的组成、定义和权重等都在不断变化。奶牛的选育是从关注产奶性能而开始,随后增加了体型外貌性状。由于奶牛的健康和繁殖问题的增加以及社会对动物福利的不断关注,20世纪末,世界范围内平衡育种理念在奶牛育种中逐渐形成,一些重要的功能性状加入各国的选择指数中;进入21世纪后,随着奶牛养殖业和社会的发展,育种家们开始关注和研究更多的性状,部分新性状已经开始在育种实践中选育应用。本文通过整理奶牛育种中有关新性状的研究并收集各国奶牛选育方案中的相关信息,综述了近十年奶业发达国家在奶牛遗传选育中正在研究或已经开始应用的新性状,并将这些新性状分为生产效率相关的新性状、应对环境挑战的新性状、健康福利相关的新性状、产品和加工相关的新性状及管理相关的新性状五大类,总结了这些性状的选育背景、定义方法、遗传基础和选育应用情况等,最后还总结了奶牛育种中新性状的研究应用过程,以期为我国奶牛遗传育种研究和育种目标完善提供一定的借鉴。