美国土壤熏蒸剂使用风险管理措施

概述了美国土壤熏蒸剂登记和应用情况,介绍了美国为降低土壤熏蒸剂使用风险所采取的措施。结合我国土壤熏蒸剂登记及使用实际,提出了加强我国农药使用管理、降低使用风险的措施。     

美国EPA登记的生物农药有效成分名录

本文列出了截止2009年4月1日。美国环保局农药项目办公室公布登记的319种生物农药有效成分名单。     

部分国家的政府农业科技投入政策分析

对美国、英国、日本、法国等国家近年来的政府农业科技投入政策进行了调查与分析,在此基础上总结了这些国家政府通过国家财政投入政策支持农业科技创新的共性特征。     

美国林化产品出口贸易动态分析

对美国近年来(1994～1999)的主要林化产品出口贸易量进行了分析,发现美国林化产品出口贸易额波动较大,脂松香、松节油类及其深加工产品的贸易额在稳步上升,而萜烯油类等产品贸易量在下降。同时,分析了影响美国林化产品贸易量变化的因素,提出了我国林化企业调整产品结构,扩大国际市场份额的发展方向。     

中国猪肉价格波动研究——兼与美国的比较

猪肉价格的大幅波动给我国的生猪生产及猪肉消费带来极大的影响。本文通过对1995年以来猪肉月度价格变动及1985到2006年生猪及猪肉年度价格波动的分析,探讨我国猪肉市场价格的长短期变动规律,并从生猪的生产结构、生产周期、生产成本、疫情、宏观环境及与美国的猪肉市场的国际比较等方面解析中国猪肉价格波动的原因。提出鼓励并扶持生猪的规模化生产、提高生猪行业的组织化程度、加大政府投入力度、完善动物防疫体系等主要对策措施。     

赴美国肉牛规模化生产技术考察团考察报告（二）——释惑美国肉牛生产技术之妙

美国是世界肉牛业最发达的国家之一,其肉牛产业链较健全、组织化程度较高。美国的肉牛品种有100多个,但常用的只有10个左右,其中,安格斯牛占全关登记注册种牛的40％。美国有95％的肉牛进行本交,只有5％的肉牛开展人工授精;商品牛群充分利用杂交优势来提高经济利益。美国在肉牛育肥方式上特别是高能量饲料和高蛋白饲料的应用上是非常科学合理的。     

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.     

世界各国家禽饲养标准参数浅析

本文综述了中、美、澳、日、法及前苏联六国最新发表的有关禽类饲养标准等方面的研究成果,分家禽能量需要量及能量蛋白比、蛋白质及氨基酸需要量、矿物质需要量、微量元素需要量、维生素需要量五部分,按家禽类型、生长阶段、生产性能等分别进行了分析比较,以资参考。     

Landowner Perceptions of Legal Liability for Using Prescribed Fire in the Southern Plains,United States

Suppression of fire in the Southern Plains has led to proliferation of woody plants and fuel load accumulation that spurs wildfires. These effects have led to calls for widespread application of prescribed fire to reduce fuel loads, but there is substantial landowner resistance to the use of this land management tool. Here we explore factors that affect perceptions of landowners in the Southern Plains about prescribed fire liability and their willingness to apply this land management tool. This region was selected for the study because of the preponderance of private landholdings and widespread woody plant encroachment. The study used a mail survey of 1 853 landowners in 16 counties in Texas and Oklahoma, resulting in a data set from 680 respondents (37% useable response rate). Logistic regression models were developed to test three hypotheses relating to the likelihood that a landowner will apply prescribed fire. The study corroborated that landowners who perceived higher levels of fire-related legal liability were less likely to apply prescribed fire on their land or assist with its application on other properties. In addition, burn bans were found to inhibit landowner willingness to apply fire during periods that result in higher woody plant mortality. Oklahoma respondents, landowners who believed prescribed fire to be an affordable woody plant management tool, and members of prescribed burning associations (PBAs) were more likely to use prescribed fire. These results have important implications for policies aimed at overcoming resistance to the use of prescribed fire to curb woody plant encroachment and reduce fuel load accumulation. Specifically, language in state statutes pertaining to prescribed fire should be modified to reduce landowner concerns over legal liability; PBAs should be established more widely; and public cost-sharing funds for woody plant management should prioritize prescribed fire.     

Evaluating Domestic Sheep Survival with Different Breeds of Livestock Guardian Dogs

Livestock guard dogs (LGDs; Canis familiaris) have been widely adopted by domestic sheep (Ovis aries) producers because they reduce predation by wild carnivores. LGDs were originally used in the United States to reduce coyote (Canis latrans) depredations, but their efficacy against a suite of large carnivores, including wolves (Canis lupus), brown bears (Ursus arctos), black bears (Ursus americanus), and cougars (Puma concolor), and whether specific breeds perform better than others remains unclear. To assess breed-specific effectiveness at reducing depredations from a suite of livestock predators, we compared survival rates of sheep protected by different breeds of LGDs, including three breeds from Europe (Turkish kangal, Bulgarian karakachan, and Portuguese cão de gado transmontano) and mixed-breed LGDs, “whitedog,” common in the United States. With the help of participating sheep producers, we collected cause-specific mortality data from domestic sheep in Idaho, Montana, Oregon, and Wyoming between 2013 and 2016. All three of the novel breeds of LGD tested were associated with overall reductions in sheep depredation relative to whitedogs, ranging from 61% to 95% (P < 0.05). In terms of predator-specific effectiveness, the Turkish kangal was associated with decreases in depredation from cougars (e^β = 0.31, 95% CI = 0.10–0.94, P = 0.04), black bears (e^β = 0.33, 95% CI = 0.28–0.37, P < 0.01), and coyotes (e^β = 0.56, 95% CI = 0.35–0.90, P = 0.02). The Bulgarian karakachan was associated with a decrease in coyote depredations (e^β = 0.07, 95% CI = 0.01–0.49, P < 0.01). The Portuguese transmontano was not associated with significant reductions in depredation hazard for any specific predator. Although variations in breed-specific effectiveness were subtle and nuanced, these findings will help livestock producers and wildlife managers make tailored decisions about how best to incorporate different breeds of LGD into sheep grazing regimes.