有机无机肥配施比例对蔬菜产量和品质及土壤重金属含量的影响

关于蔬菜施有机肥和它与无机肥的合理配施比例,对蔬菜的产量和品质有重要影响,对土壤有机质和重金属含量也有影响。为控制施禽畜粪类有机肥对蔬菜的负面影响,探讨蔬菜的合理施用量和有机/无机肥配施比例,在不同质地的土壤上进行田间试验。结果表明,(1)施过量禽畜粪类有机肥对试验蔬菜产量和品质都会产生不良影响,小白菜(Brassica chinensis)和茄子(Eggplant)施禽畜粪超过22500kg/hm2、马铃薯(Solanum tuberosum L.)超过24000kg/hm2时,其产量不再增加,成活率下降,维生素C含量下降,多个试验均表现出有机肥用量增加而小白菜硝酸盐随之增加的典型特征;同时不论土壤的质地轻重,蔬菜重金属Pb有随禽畜粪用量增加而提高的趋势;在质地较轻的土壤上,蔬菜重金属Cd、As有随禽畜粪用量增加而提高的趋势;小白菜施禽畜粪肥超过7500kg/hm2、茄子和冬种马铃薯施禽畜粪肥超过75000kg/hm2,收获后土壤重金属含量高于对照和施无机肥的总Cr和As。(2)蔬菜单独施用有机肥的合适施用量,小白菜在较粘重的土壤上可施到22500kg/hm2,但有机肥与无机肥配合施用时有机肥用量可减量;茄子合适施用量应在22500kg/hm2左右;冬种马铃薯合适施用量应在24000kg/hm2左右。(3)蔬菜的有机/无机肥合理配比,小白菜、茄子、和冬种马铃薯施肥的有机氮与无机氮之比均为0.25∶1至0.5∶1时其产量和品质水平较佳。     

Infectious Diseases and Extinction Risk in Wild Mammals

Abstract:  Parasite-driven declines in wildlife have become increasingly common and can pose significant risks to natural populations. We used the IUCN Red List of Threatened and Endangered Species and compiled data on hosts threatened by infectious disease and their parasites to better understand the role of infectious disease in contemporary host extinctions. The majority of mammal species considered threatened by parasites were either carnivores or artiodactyls, two clades that include the majority of domesticated animals. Parasites affecting host threat status were predominantly viruses and bacteria that infect a wide range of host species, including domesticated animals. Counter to our predictions, parasites transmitted by close contact were more likely to cause extinction risk than those transmitted by other routes. Mammal species threatened by parasites were not better studied for infectious diseases than other threatened mammals and did not have more parasites or differ in four key traits demonstrated to affect parasite species richness in other comparative studies. Our findings underscore the need for better information concerning the distribution and impacts of infectious diseases in populations of endangered mammals. In addition, our results suggest that evolutionary similarity to domesticated animals may be a key factor associated with parasite-mediated declines; thus, efforts to limit contact between domesticated hosts and wildlife could reduce extinction risk.     

Quantification and Index of Non-Point Source Pollution in Taihu Lake Region with GIS

The contribution of phosphorus and nitrogen from non-point source pollution (NPS) in the Taihu Lake region was investigated through case study and surveying in the town of Xueyan, From experimental results coupled with survey and statistics in the studied area, the distribution of nitrogen and phosphorus input to the water body is achieved from four main sources: agricultural land, village, the town center and the poultry factory. The results showed that about 38% of total phosphorus (TP) and 48% of total nitrogen (TN) discharged is from agricultural land, 33% of TP and 40% TN from village residents, 25% of TP and 10% of TN from the town center and 4% of TP and 2% of TN from the poultry factory.The Agricultural Non-point Pollution Potential Index (APPI) system for identifying and ranking critical areas of NPS was established with a Geographic Information Systems (GIS)-based technology. Quantification of the key factors in non-point sources pollution was carried out utilizing the following: Sediment Production Index (SPI), Runoff Index (RI), People and Animal Loading Index (PALI) and Chemical Use Index (CUI). These are the core parts of the model, and the weighting factor of each index was evaluated according the results of quantification. The model was successfully applied for evaluating APPI in Xueyan. Results from the model showed that the critical area identified for NPS control in Xueyan. The model has several advantages including: requiring fewer parameters, easy acquirement of these parameters, friendly interface, and convenience of operation. In addition it is especially useful for identifying critical areas of NPS when the basic data are not fully accessible, which is the present situation in China.     

经济野生动物养殖管窥之见

本文对我国经济动物养殖业具有的高投入高产出,市场行情变化大,风险大,需要较特殊的养殖技术,以及易被炒种形成“养殖热”等特点进行了精辟的论述,并从此出发分析了经济野生动物的养殖必须具备足够的资金,懂法守法,懂得养殖技术,有较好的环境条件,种原优质和掌握市场行情等条件,对于我国经济动物养殖业大起大落以及产品价廉质差滞销的原因进行了深入分析,并就如何健康发展经济动物养殖业提出了针对性措施。     

猪场废弃物强制通风静态仓堆肥系统的试验研究

通过组织5个猪场废弃物堆肥试验，度量温度、表观性状、体积、重量损失、全氮、全磷、大肠杆菌值、蛔虫卵杀灭率和发芽指数等指标，检验了开发的强制通风静态仓堆肥系统的性能。结果表明，除起始含水率为80％试验堆体因起始含水率过高导致发生厌氧反应外，其余4个堆体均实现堆肥无害化、减量化、稳定化和资源化的处理目标；堆肥温度维持50℃以上5—7d，或55℃以上3d是大肠杆菌值达到国家粪便无害化卫生标准的必要条件；堆肥过程能有效脱除堆料的生物毒性，后腐熟阶段是必需阶段；氮、磷、钾等主要营养元素在堆肥前后呈现“浓缩效应”。因此，堆肥化能提高猪场废弃物肥效和利用价值。     

九龙江流域规模化养殖环境风险评价

在G IS支持下采用养分收支平衡法对九龙江流域规模化生猪养殖的环境风险进行评价。规模化养殖污染负荷在不同类型养殖场的分配、空间分布规律以及规模化养殖的环境风险评价结果表明:规模化养猪业年产粪尿量达107万t,以小型规模化养殖场产生的污染负荷最高;整体来看,规模化生猪养殖的环境风险不大,但由于养殖场的地理分布集中,造成近郊区域规模化养殖的环境风险极高;由于过多施用化肥,中远郊规模化养殖粪尿未得到合理利用而流失。位于水系附近的养殖场对水体影响较大,根据“福建省畜禽养殖污染防治管理办法”,为减少规模化生猪养殖对九龙江水质的直接威胁,需搬迁主要支流沿岸1 km范围内的规模化养猪场250个。     

反刍动物甲烷排放研究进展

反刍动物甲烷排放是大气中甲烷的主要排放源之一,本文简述了国内外反刍动物甲烷排放总量研究概况,及甲烷排放研究尚存在的问题和初步结论。     

青铜峡高氟地区天然氟污染对畜牧业的危害及经济损失初探

调查了宁夏青铜峡贺兰山东麓冲积、洪积的干旱荒漠草原约２００ｋｍ２的水氟、表层土壤水溶氟、牧草氟、大气含氟量和在当地放牧的牧羊业受氟害的情况。结果表明．这里的水氟、土壤水溶氟、牧草含氟量等均比氟安全区偏高，属自然高氟地区。自然高氟地区对牧羊业的危害－主要使母羊寿命比氟安全区约减少一半而造成经济损失，经估算每平方千米约损失３８０元。     

安徽野生动物资源及其开发利用与保护

安徽省自然条件优越,野生动物资源丰富,但在资源的开发利用上存在不少问题。只有在科学研究的基础上,把资源的开发利用与保护有机地结合起来,才能实现野生动物资源的永续利用。     

Modeling thermal effect on growth of chinese shrimp, Penaeus chinensis (Osbeck)

A couple of experiments were conducted to estimate the optimal temperature effect on growth of Chinese shrimp (Penaeus chinensis). The equation describing growth-temperature relationship derived from the first experiment with temperature ranging from 16° to 31°C was found linear as the following:

G = -0.005667 + 0.001103 T

,where G and T are daily growth rate and temperature, respectively.The second experiment indicated that the daily growth rate was a quadratic function of temperature at the limits of 27° and 35°C. The equation was

G = -0.339587 + 0.023476 T − 0.000375 T²

.The optimal temperature in terms of maximum growth was 31.26°C.