共查询到20条相似文献，搜索用时 15 毫秒
1.
Katrien Descheemaeker Tilahun Amede Amare Haileslassie 《Agricultural Water Management》2010,97(5):579-586
In sub-Saharan Africa problems associated with water scarcity are aggravated by increasing demands for food and water, climate change and environmental degradation. Livestock keeping, an important livelihood strategy for smallholder farmers in Africa, is a major consumer of water, and its water consumption is increasing with increasing demands for livestock products. At the same time, current low returns from livestock keeping limit its contribution to livelihoods, threaten environmental health and aggravate local conflicts. The objectives of this review are to: (1) synthesize available knowledge in the various components of the livestock and water sectors in sub-Saharan Africa, (2) analyze livestock-water interactions and (3) identify promising strategies and technological interventions for improved livestock water productivity (LWP) using a framework for mixed crop-livestock systems. The interventions are grouped in three categories related to feed, water, and animal management. Feed related strategies for improving LWP include choosing feed types carefully, improving feed quality, increasing feed water productivity, and implementing grazing management practices. Water management for higher LWP comprises water conservation, watering point management, and integration of livestock production in irrigation schemes. Animal management strategies include improving animal health and careful animal husbandry. Evidence indicates that successful uptake of interventions can be achieved if institutions, policies, and gender are considered. Critical research and development gaps are identified in terms of methodologies for quantifying water productivity at different scales and improving integration between agricultural sectors. 相似文献
2.
Water harvesting and supplemental irrigation for improved water productivity of dry farming systems in West Asia and North Africa 总被引：1，自引：0，他引：1
In the dry areas, water, not land, is the most limiting resource for improved agricultural production. Maximizing water productivity, and not yield per unit of land, is therefore a better strategy for dry farming systems. Under such conditions, more efficient water management techniques must be adopted. Supplemental irrigation (SI) is a highly efficient practice with great potential for increasing agricultural production and improving livelihoods in the dry rainfed areas. In the drier environments, most of the rainwater is lost by evaporation; therefore the rainwater productivity is extremely low. Water harvesting can improve agriculture by directing and concentrating rainwater through runoff to the plants and other beneficial uses. It was found that over 50% of lost water can be recovered at a very little cost. However, socioeconomic and environmental benefits of this practice are far more important than increasing agricultural water productivity. This paper highlights the major research findings regarding improving water productivity in the dry rainfed region of West Asia and North Africa. It shows that substantial and sustainable improvements in water productivity can only be achieved through integrated farm resources management. On-farm water-productive techniques if coupled with improved irrigation management options, better crop selection and appropriate cultural practices, improved genetic make-up, and timely socioeconomic interventions will help to achieve this objective. Conventional water management guidelines should be revised to ensure maximum water productivity instead of land productivity. 相似文献
3.
《Agricultural Systems》2002,71(1-2):41-57
Smallholder crop–animal systems predominate in south Asia, and most of the projected future demands for ruminant meat and milk are expected to be met from the improved productivity of livestock in these mixed farming systems. Despite their importance in the sub-region, there is a paucity of information on research that incorporates animals interactively with cropping. Livestock research has tended to highlight component technologies, often treating diverse and complex mixed farming operations as a single system. Furthermore, little attention has been paid to social, economic or policy issues. Thus, many of the technological interventions have either failed to become adopted at farm level or their uptake has proved unsustainable. This paper reviews aspects of animal production in South Asia; the trends and forecasts for animal populations and products, constraints to productivity, research opportunities and some key examples of technologies that have failed to achieve their full potential on farm. A systems analysis of small-scale crop–livestock operations is advocated, as a precursor for targeting appropriate interventions at farm level to increase animal productivity and protect the natural resources base. 相似文献
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The study investigates the possibility of enhancing crop water productivity in the parts of Northwest India where groundwater quality is marginal and canal water supply is severely scarce. Soil, Water, Atmosphere and Plant (SWAP) model was calibrated and validated in three farmers’ fields with varying canal water availability and groundwater quality in the Kaithal Irrigation Circle of the Bhakra Canal system, Haryana. On the basis of predicted and observed soil water content, pressure heads, salt concentration at 2 week intervals and crop yields, the model was found suitable for use in the region. A few nomographs were prepared to provide a graphical method to predict the effect of different combinations of water quality and depth of water application on crop yield and soil salinity and to help develop some guidelines to the farming community. Water management alternatives at the field level were suggested to increase the yield and to maintain soil salinity below threshold level. The application of frequent irrigation in precisely leveled field would help in achieving 10% higher yield even when saline groundwater of 11 dS/m is used for irrigation. 相似文献
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滕光辉 《智慧农业(中英文)》2019,1(3):1-12
畜禽设施精细养殖是现代畜牧业发展的前沿领域,其核心在于物联网与传统设施养殖的深度融合。近年来,随着传统家庭式养殖模式逐渐退出,中国畜禽养殖场的管理方式已逐步迈向集约化、规模化和设施化,基于养殖动物个体管理和质量保障且满足动物福利要求的畜禽设施精细化养殖已成为畜禽养殖业的最新发展趋势。本文在阐述畜禽设施精细养殖信息感知与环境调控的重要性的基础上,介绍了信息感知与环境调控相关前沿技术,分析了面临的问题与挑战,指出智能传感器技术将成为推动畜禽设施精细养殖进步的底层驱动技术,兼顾畜禽福利和生产性能的动物拟人化智能调控技术和策略等是面临的重要挑战。最后,就中国畜禽设施精细养殖关键技术如何落地提出了相关建议,旨在为中国畜禽设施养殖业的转型升级和可持续发展提供理论参考和技术支撑。 相似文献
8.
《Agricultural Systems》2002,71(1-2):169-177
The importance of crop–animal systems in Asia, the multiple roles played by animals and the opportunities for increasing their contribution to these systems justifies continued research effort. An assessment of the role of livestock in mixed farming systems in 14 countries has identified priority systems, technical constraints and weaknesses in the national organisations. Future research needs to focus on the rain-fed production systems, where most of the livestock are found. There is an overriding need for a farming systems perspective to the research agendas that involves inter-disciplinarity and community-based participation. Such an approach will be more complex, require concentrated effort and more efficient resource use, but will be associated with considerable benefits due to a greater integration of effort. 相似文献
9.
Managing natural resources of watersheds in the semi-arid tropics for improved soil and water quality: A review 总被引：1，自引：0，他引：1
Soil, water and production systems constitute the most important natural resources of a watershed in the rainfed agro-ecosystem; and for sustainability of the production systems they need to be in harmony with the environment. To learn from the past research, a review is made of literature on the impact of natural resource management practices on soil and water quality in the semi-arid tropical regions of India. The results from long-term on station field experiments show that an integrated use of soil and water conservation practices with balanced plant nutrition can not only sustain increased productivity but also maintain soil quality at the watershed or catchment level. Natural resource management practices that conserve soil and water also help to maintain surface and groundwater quality. The changes in soil and water quality, as impacted by natural resource management practices, need to be monitored and assessed on a continuing basis as the outcome of such research offers valuable opportunity for the implementation of corrective management practices, as and when needed. 相似文献
10.
Nutrient flux and balance studies are valuable tools to assess the sustainability of agro-ecosystems and potential consequences for agricultural productivity. This paper presents results from a study at the field/farm scale representing mixed farming systems typical for the East African Highlands. We selected catchments in the Dega (cool highlands and Woina Dega (warm-to-cool mid-highlands) of the Central Highlands of Ethiopia, to get more insight on how individual land use strategies and access to resources affect the magnitude of nutrient flows and resulting balances and to explore some of reasons of the variability within and between farming systems at different altitudes. Our results show that environmental condition, farming system (e.g. choice of crop), access to resources (e.g. land, livestock and fertilizer) and smallholders’ source of off farm income influence the magnitude of nutrient fluxes and the degree to which nutrient fluxes may be imbalanced. 相似文献
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家畜智能养殖设备是智能农机装备的组成部分之一,是国际农业装备产业技术竞争的焦点。本文重点围绕家畜智能养殖设备与饲喂技术在实践中的应用,进行了系统的性能特点分析。目前家畜智能养殖设备的开发对象主要针对猪和奶牛,主要研发的系统包括妊娠母猪电子饲喂站、哺乳母猪精准饲喂系统、奶牛精准饲喂系统和挤奶机器人等。家畜智能养殖设备的工业化应用必须与养殖模式、畜舍结构布局结合起来,才能发挥设备的使用效率,同时从满足动物的福利出发,与动物生理、生长及行为结合起来,形成设备与动物的互作和相互适应。最后指出了智能设备的研究必须与畜牧业生产的理论、目标产品的功能驱动及养殖方式的创新协调一致,要不断地更新换代,才能助推畜牧业的转型升级。 相似文献
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在山田河流域利用SWAT模型对循环灌溉稻田和畜牧生产系统的流域特征进行调查。在茨城县地区土地利用呈现典型的景观镶嵌式。谷地中的稻田循环灌溉系统沿河岸在低处修建,森林、菜地和畜禽舍则建在周围地势较高处。灌期与非灌期土壤径流特征存在明显差异,通过设定参数可以利用SWAT模型对径流进行预测。灌期效率系数(ENS)、系数测定(r2)和相对误差(RE)分别为0.86、0.87和2.0%,非灌期分别为0.67、0.68和2.6%。但是对于养分浓度,模型没法给出满意的预测。对菜田及牲畜废弃物养分的模拟应对SWAT进行修正,对稻田系统的模拟应对算法进行修订。 相似文献
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Life cycle assessment of Swiss farming systems: II. Extensive and intensive production 总被引：1，自引：0，他引：1
Thomas Nemecek Olivier Huguenin-ElieDavid Dubois Gérard GaillardBritta Schaller Andreas Chervet 《Agricultural Systems》2011,104(3):233-245
Extensive or low-input farming is considered a way of remedying many problems associated with intensive farming practices. But do extensive farming systems really result in a clear reduction in environmental impacts, especially if their lower productivity is taken into account? This question is studied for Swiss arable cropping and forage production systems in a comprehensive life cycle assessment (LCA) study.Three long-term experiments (DOC experiment comparing bio-dynamic, bio-organic and conventional farming, the “Burgrain” experiment including integrated intensive, integrated extensive and organic systems and the “Oberacker” experiment with conventional ploughing and no-till soil cultivation, are considered in the LCA study. Furthermore, model systems for arable crops and forage production for feeding livestock are investigated by using the Swiss Agricultural Life Cycle Assessment method (SALCA).The analysis covers an overall extensification of cropping systems and forage production on the one hand and a partial extensification of fertiliser use, plant protection and soil cultivation on the other. The overall extensification of an intensively managed system reduced environmental impacts in general, both per area unit and per product unit. In arable cropping systems medium production intensity gave the best results for the environment, and the intensity should not fall below the environmental optimum in order to avoid a deterioration of eco-efficiency. In grassland systems, on the contrary, a combination of both intensively and extensively managed plots was preferable to medium intensity practices on the whole area. The differences in yield, production intensity and environmental impact were much more pronounced in grassland than in arable cropping systems.Partial extensification of a farming system should be conceived in the context of the whole system in order to be successful. For example, the extensification solely of fertiliser use and soil cultivation resulted in a general improvement in the environmental performance of the farming system, whereas a reduction in plant protection intensity by banning certain pesticide categories reduced negative impacts on ecotoxicity and biodiversity only, while increasing other burdens such as global warming, ozone formation, eutrophication and acidification per product unit. The replacement of mineral fertilisers by farmyard manure as a special form of extensification reduced resource use and improved soil quality, while slightly increasing nutrient losses.These results show that a considerable environmental improvement potential exists in Swiss farming systems and that a detailed eco-efficiency analysis could help to target a further reduction in their environmental impacts. 相似文献
14.
In face of climate change and other environmental challenges, one strategy for incremental improvement within existing farming systems is the inclusion of perennial forage shrubs. In Australian agricultural systems, this has the potential to deliver multiple benefits: increased whole-farm profitability and improved natural resource management. The profitability of shrubs was investigated using Model of an Integrated Dryland Agricultural System (MIDAS), a bio-economic model of a mixed crop/livestock farming system. The modelling indicated that including forage shrubs had the potential to increase farm profitability by an average of 24% for an optimal 10% of farm area used for shrubs under standard assumptions. The impact of shrubs on whole-farm profit accrues primarily through the provision of a predictable supply of ‘out-of-season’ feed, thereby reducing supplementary feed costs, and through deferment of use of other feed sources on the farm, allowing a higher stocking rate and improved animal production. The benefits for natural resource management and the environment include improved water use through summer-active, deep-rooted plants, and carbon storage. Forage shrubs also allow for the productive use of marginal soils. Finally, we discuss other, less obvious, benefits of shrubs such as potential benefits on livestock health. The principles revealed by the MIDAS modelling have wide application beyond the region, although these need to be adapted on farm and widely disseminated before potential contribution to Australian agriculture can be realized. 相似文献
15.
《Agricultural Systems》1999,62(3):169-188
Appropriate selection of holistic management strategies for livestock farming systems requires: (1) understanding of the behaviour of, and interrelations between, the different parts of the system; (2) knowledge of the basic objectives of the decision maker managing such enterprise; and (3) understanding of the system as a whole in its agro-ecoregional context. A decision-support system based on simulation and mathematical programming techniques has been built to represent pastoral dairy production systems. The biological aspects (grass growth, grazing, digestion and metabolism, animal performance) are represented by simulation studies under a variety of management regimes. The outputs from the simulation runs (such as pasture utilisation, stocking rates, milk yields, fertilizer use, etc.) are used as data input to the multi-criteria decision-making models, and the latter have been used to select the management strategies which make the most efficient use of the farm's resources (i.e. land, animals, pastures). The paper discusses the effects and implications of different management scenarios and policies on the bio-economic performance of highland dairy farms in Costa Rica. Nevertheless, the model frameworks are generic and can be adapted to different farming systems or ruminant species. The effect of model formulation and sensitivity, different decision-maker objectives, and/or activity or constraint definitions on management strategy selection are also analysed. 相似文献
16.
Seleshi Sisaye 《Agricultural Systems》1980,5(1):29-38
Amare Getahun's (1978) paper on agricultural systems in Ethiopia is one of the few attempts to classify agricultural systems in Ethiopia into (a) the highland mixed farming system, (b) low plateaux and valley mixed agriculture, (c) pastoral livestock production of the arid and semi-arid zones and (d) commercial agriculture, and to describe the main characteristics of each system. However, it is not clear what criteria have been used to classify the different agricultural regions into the four general categories developed by Amare Getahun. This review paper discusses agricultural systems by applying the ecological systems approach to agricultural development within the framework of a political economy analysis as a means of evaluating agricultural development strategies. 相似文献
17.
秦晓磊 《国际沙棘研究与开发》2017,(5)
通过对凌海市节水增粮建设规模、取用水方案及取水合理性分析,其水资源开发利用通过采取管灌、膜下滴灌等工程,可以提高项目区水土资源利用效率,从而达到合理开发利用水资源的目的.本文并对取水的影响与补偿措施提出合理化建议.该项目的实施有利于提高农业综合生产力,保障粮食增产增收. 相似文献
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S. Lecina C.M.U. NealeG.P. Merkley C.A.C. Dos Santos 《Agricultural Water Management》2011,98(9):1349-1363
The purpose of this work is to contribute to the development of a combined approach to evaluate irrigated areas based on: (1) irrigation performance analysis intended to assess the productive impacts of irrigation practices and infrastructures, and (2) water accounting focused on the hydrological impacts of water use. Ador-Simulation, a combined model that simulates irrigation, water delivery, and crop growth and production was applied in a surface irrigated area (1213 ha) located in the Bear River Irrigation Project, Utah, U.S.A.. A soil survey, a campaign of on-farm irrigation evaluations and an analysis of the database from the Bear River Canal Company and other resources were performed in order to obtain the data required to simulate the water flows of the study area in 2008. Net land productivity (581 US$ ha−1) was 20% lower than the potential value, whereas on-farm irrigation efficiency (IE) averaged only 60%. According to the water accounting, water use amounted to 14.24 Mm3, 86% of which was consumed through evapotranspiration or otherwise non-recoverable. Gross water productivity over depleted water reached 0.132 US$ m−3. In addition, two strategies for increasing farm productivity were analyzed. These strategies intended to improve water management and infrastructures raised on-farm IE to 90% reducing the gap between current and potential productivities by about 50%. Water diverted to the project was reduced by 2.64 Mm3. An analysis based on IE could lead to think that this volume would be saved. However, the water accounting showed that actually only 0.91 Mm3 would be available for alternative uses. These results provide insights to support the decision-making processes of farmers, water user associations, river basin authorities and policy makers. Water accounting overcomes the limitations and hydrological misunderstandings of traditional analysis based on irrigation efficiency to assess irrigated areas in the context of water scarcity and competitive agricultural markets. 相似文献
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Water is the principal limiting resource in Australian broadacre farming, and the efficiency with which farmers use water to produce various products is a major determinant both of farm profit and of a range of natural resource management (NRM) outcomes. We propose a conceptual framework based on multiple water use efficiencies (WUEs) that can be used to gain insight into high-level comparisons of the productivity and sustainability of alternative farming practices across temporal and spatial scales. The framework is intended as a data aggregation and presentation device. It treats flows of water, biomass and money in a mixed farming system; economic inefficiencies in these flows are tracked as they are associated with a range of NRM indicators.We illustrate the use of the framework, and its place in a larger research programme, by employing it to synthesise the results from a set of modelling analyses of the effect of land use choices on long-term productivity and a range of NRM indicators (frequency of low ground cover, deep drainage, N leaching rates and rate of change in surface soil organic carbon). The analyses span scales from single paddocks and years to whole farms and have been carried out with the APSIM and GRAZPLAN biophysical simulation models and the MIDAS whole-farm economic model.In single wheat crops in one study, different land uses in preceding years affect grain yield primarily by affecting the harvest index. When the scale changes to cropping rotations, the critical factor affecting overall water use efficiency is found to be the proportion of stored soil water that is transpired by crops. When ordinated in terms of their water use efficiencies, a set of 45 modelled rotation sequences at another location are differentiated mainly by the proportion of pasture in the rotation; when rotations are ordinated using key NRM indicators, the proportion of lucerne pasture is the main distinguishing factor. Finally, we show that for whole crop-livestock farms at three different locations across southern Australia, the pattern of water use efficiencies in the most profitable farming systems changes in similar ways as cropping proportion is altered. At this scale, land use choices affect multiple water use efficiency indices simultaneously and commodity prices determine the balance of the resulting economic tradeoffs.Limitations to the use of the WUE framework arising from its relative simplicity are discussed, as are other areas of farming systems research and development to which it can be applied. 相似文献
20.
Water production functions are used to model yield response to various levels of supplemental irrigation (SI), to assess water productivity coefficients, and to identify optimum irrigation under various input-output price scenarios. The SI production function is taken as the difference between the total water production function (irrigation + rain) and that of rainwater. Theoretical analysis of the unconstrained objective function shows that the seasonal depth of SI to maximize profit occurs when the marginal product of water equals the ratio of unit water cost to unit product sale price. Applying this analysis to wheat in northern Syria, the production functions of SI under different rainfall conditions are developed. Coupled with current and projected water costs and wheat sale prices, the functions are used to develop an easy-to-use chart for determining seasonal irrigation rates to maximize profit under a range of seasonal rainfall amounts.Results show that, for a given seasonal rainfall, there is a critical value for the ratio of irrigation cost to production price beyond which SI becomes less profitable than rainfed production. Higher product prices and lower irrigation costs encourage the use of more water. Policies supporting high wheat prices and low irrigation costs encourage maximizing yields but with low water productivity. The resulting farmer practice threatens the sustainability of water resources. Balancing profitability versus sustainability is a challenge for policy makers. Our analysis can help national and local water authorities and policy makers determine appropriate policies for water valuation and allocation; and assist extension services and farmers in planning irrigation infrastructure and farm water management. 相似文献