晋东豫西旱农试验区农业生态系统能流特征

以晋东豫西旱农试验区－－山西省寿阳县宗艾镇宗艾村农业生态系统为研究对象,分析了农田、果园、林业和畜牧业等亚系统能量流动途径、人工辅助能输入、能量产出,能量结构偏差以及能量转化效率等能流特征。结果表明：（１）由于能量投入低,尽管利用效率较高,但能量产出仍处于低水平阶段。农田生态系统的有机能投入和人工辅助能总投入很低,低于１９７９年全国平均水平,但能量产投比较高,增加人工辅助能投入、提高有机能投入比例     

农牧结合生态工程的基本理论与实践

农牧结合生态工程是一个复杂的农业生态、经济和技术系统工程,它由植物(种植业)、动物(养殖业)和微生物(连接种养业)3个子系统组成,其关键是建设一个以"四、三、二、一"畜牧业生产模式为主要内容的高效节粮型畜牧生态工程,它要求用尽可能少的自然资源,在尽可能短的周期内,生产尽可能多而优的农(牧)产品,以获取尽可能高的经济效益,达到或维持尽可能最佳的生态平衡.     

Mate guarding in the Linnet Carduelis cannabina

Capsule?House Sparrow (Passer domesticus) populations in south Swedish farmland are not affected by supplemental winter feeding, irrespective of agricultural landscape type or presence of animal husbandry, although winter populations declined more in mixed farmland and when farms contained animal husbandry.

Aims?To investigate whether food limitation of House Sparrow population size during the winter varied spatially in relation to agricultural landscape intensification and farm management.

Methods?We experimentally increased the winter food supply for populations on farmsteads in replicated landscapes that differed in agricultural intensification (open plains versus mixed farming) and/or farm management (crop farming versus animal husbandry), and estimated possible differences in effects on winter population change.

Results?We found no effect of supplementary winter feeding on changes in House Sparrow population sizes over the winter, irrespective of agricultural landscape type or presence of animal husbandry at the farm. However, we found a significantly larger winter population decline in mixed farmland and when farms contained animal husbandry.

Conclusions?The results suggest that House Sparrow populations in south Swedish farmland are not primarily limited by winter food availability. Alternatively, supplemental winter feeding may augment interspecific competition or attracts predators, offsetting any positive effect on population change. However, the stronger population decline in landscapes in which more breeding resources may be available (animal husbandry farms, mixed farmland), suggests stronger intraspecific competition during the winter in line with the resource separation hypothesis.     

Conventional and Land-Time Budget Analysis of Rural Villages in Hubei Province,China

Five rural villages in Qianjiang County (Hubei province), PR China, were investigated to collect information on the socioeconomic characteristics relevant to farming system analysis. In each village, 50 households were randomly sampled and household heads interviewed. We first present the results of this conventional survey, which describes these five villages in terms of conventional socioeconomic parameters such as demographic variables, land availability and profiles of land use, time allocation and profiles of working time use, cash flows, and degree of food self-sufficiency. Then we change focus by characterizing household types rather than village types. This is done analyzing the same raw data aggregated at the household level to illustrate the difference of a parallel readings at different hierarchical levels. Finally, we present a new approach to organize the information gathered in the conventional way into “typologies” referring to both household and village level. Such a passage makes possible a multidimensional reading of the system. One key concept of this analysis is the land-time budget (LTB) approach, which is first explained in theoretical terms and then illustrated with examples applied to our data set.     

畜牧系统中氮素平衡计算参数的探讨

畜牧系统中N流动与平衡的研究是畜牧业进行养分资源管理的基础,而参数的确定又是研究养分循环与平衡的基础工作.本研究对该系统的N输入、输出项参数进行分析讨论,包括平衡计算中每一个输入和输出项需要的参数种类、参数的选择以及建议采用的数值.讨论过程参考了大量的文献资料和统计数据,初步确定了我国畜牧系统N养分平衡计算参数.     

畜牧业在农业生态系统中的地位——窦店畜牧业的系统分析

本研究把畜牧业看作整个农业生态系统中的一个亚系统,定量分析了各种畜禽对能量、蛋白质和营养物质的转化效率,分析了畜牧亚系统与其它亚系统间以及与环境间的能量与物质的交流,从而对窦店畜牧业的生产力水平及其在整个农业生态系统中的地位做出客观评价,对畜牧结构的调整提出了建议,并讨论了农区畜牧业和农业生态系统的开放等问题。     

市域尺度农村系统氮素流动及污染氮足迹核算——以沈阳市为例

理解农村系统的氮素流动、排放和利用过程对减少农业活动引起的潜在环境污染和促进养分资源的可持续利用具有重要意义。本研究基于集成食物链养分流动模型和氮足迹模型,提出市域尺度农村系统氮核算框架,并从种植、动物养殖和农村人居3个子系统对1998—2018年沈阳市的氮素流、循环利用和污染氮足迹开展量化比较研究。结果表明: 2018年沈阳市种植子系统、动物养殖子系统和农村人居子系统的氮素利用率分别为36.1%、59.7%和70.1%,分别比1998年增长了15.9%、9.1%和0.7%;2018年沈阳市农村系统污染氮足迹总量为123.5 Gg,比1998年增长了21.6%;1998—2014年沈阳市农村系统污染氮足迹增长较快,随后有所下降;2018年种植子系统、动物养殖子系统和人居子系统中未利用氮素分别为129.5、62.2和8.7 Gg,相当于420.4、202.1和8.7 Gg氮肥的养分资源量。总体上,农村系统氮素利用率从生产端到消费端逐渐递增,但对农村系统氮素的时空分异情况还有待进一步的研究。     

Animal board invited review: Animal source foods in healthy,sustainable, and ethical diets – An argument against drastic limitation of livestock in the food system

Animal source foods are evolutionarily appropriate foods for humans. It is therefore remarkable that they are now presented by some as unhealthy, unsustainable, and unethical, particularly in the urban West. The benefits of consuming them are nonetheless substantial, as they offer a wide spectrum of nutrients that are needed for cell and tissue development, function, and survival. They play a role in proper physical and cognitive development of infants, children, and adolescents, and help promote maintenance of physical function with ageing. While high-red meat consumption in the West is associated with several forms of chronic disease, these associations remain uncertain in other cultural contexts or when consumption is part of wholesome diets. Besides health concerns, there is also widespread anxiety about the environmental impacts of animal source foods. Although several production methods are detrimental (intensive cropping for feed, overgrazing, deforestation, water pollution, etc.) and require substantial mitigation, damaging impacts are not intrinsic to animal husbandry. When well-managed, livestock farming contributes to ecosystem management and soil health, while delivering high-quality foodstuffs through the upcycling of resources that are otherwise non-suitable for food production, making use of marginal land and inedible materials (forage, by-products, etc.), integrating livestock and crop farming where possible has the potential to benefit plant food production through enhanced nutrient recycling, while minimising external input needs such as fertilisers and pesticides. Moreover, the impacts on land use, water wastage, and greenhouse gas emissions are highly contextual, and their estimation is often erroneous due to a reductionist use of metrics. Similarly, whether animal husbandry is ethical or not depends on practical specificities, not on the fact that animals are involved. Such discussions also need to factor in that animal husbandry plays an important role in culture, societal well-being, food security, and the provision of livelihoods. We seize this opportunity to argue for less preconceived assumptions about alleged effects of animal source foods on the health of the planet and the humans and animals involved, for less top-down planning based on isolated metrics or (Western) technocratic perspectives, and for more holistic and circumstantial approaches to the food system.     

农牧交错带农牧复合系统的可持续机制

农牧复合系统具有综合资源、兼顾生态与生计、环境与经济发展的作用,是农牧交错带脱贫富民的必由之路。目前,农牧复合实践迫切需要建立可持续的运行机制。针对于此,运用农户调查、土地养分测定和农牧测产、分室模型等方法,对宁夏盐池县皖记沟村农牧复合系统的资源支持、农户农牧复合生产方式、农牧复合系统的物质流开展研究。结果表明,促进农牧复合系统发展的主要原因是资源基础和耕地、灌木林地、草地系统耦合的生产方式。目前主要生产饲草料的水浇地和柠条林地的水资源可持续性是农牧复合系统能否长期持续的关键。加强水土资源、饲草料生产和滩羊养殖之间的系统调控和整体协同,是农牧交错带农牧复合系统可持续发展的必然选择。     

The withdrawal of antimicrobial treatment as a mechanism for defeating resistant microorganisms

Antimicrobial resistance is a major concern in health care and farming settings throughout the world. The level of antimicrobial resistance continues to increase and the requirement for a novel and possibly dramatic change in therapy choices is required. One possible mechanism for overcoming resistance is the actual removal of antimicrobial treatment from the therapeutic armoury. This review examines the potential for success of a policy advocating the reduction of antimicrobial use and additionally the withdrawal of such treatments. Evidence from agriculture suggests that the removal of certain drugs from animal husbandry can result in concomitant falls in certain drug resistances in human patients.