Multi-scale analysis of agricultural development: A modelling approach for Ilocos Norte,Philippines

Decisions and policies that have implications on allocation of resources are made at different levels. Goals at different scales may be conflicting and decisions at one scale have consequences for those at other scales. Performing analyses at more than one scale is, therefore necessary in analysing future options for resource use. This paper illustrates the use of a multi-scale method enabling assessment of multi-purpose natural resource management options. Three examples of analyses that it allows are presented for Ilocos Norte province in the Philippines, at the farm household, municipal (Batac municipality) and provincial levels. Results show that: (1) Differences in resource endowments of farm households strongly affect the potential adoption rates of five well-defined alternative technologies. (2) Limited markets, inadequate infrastructure and resource endowments of farm households have large effects on resource use and goal achievement in the municipality. Not including these factors in a resource use analysis results in a so-called aggregation bias. As these are significant, ignoring them may result in misleading simulation results and policy conclusions. The aggregation bias resulting from assuming spatially fixed input and output prices is significant for Batac, which has poor farm-to-market roads. This suggests large potential benefits from improving infrastructure. The factors investigated suggest that aggregate income in the municipality is most strongly affected by the size of the market for some vegetables. (3) The differences in resource allocations resulting from prioritizing objectives at different levels reveal potential conflicts. The municipal income was highest with crops which pose more risk to farmers; our farm household analysis shows that farmers tend not to select too much of these crops. Similarly, the provincial income is highest when resources in the province are allocated such that more of the staple crop rice and less of the highly profitable cash crops are cultivated in Batac, resulting in lower income for the municipality.     

A bio-economic modelling project for small-scale milk production systems in South-East Brasil

This paper reports on the development and use of a bioeconomic model to simulate dairy enterprises in the Zona da Mata of Minas Gerais State in south-east Brasil.In view of the relatively small size of the units, each animal within the herd is accounted for on an individual basis and the main biological events and processes are treated stochastically. Within the limits of given herdranges for genetic potentials, actual rates of performance are estimated from the levels of feeding and other management factors. An energy balance approach is used to assess the contributions of pasture, cut forage and concentrates in the diet.The model has been used to help in identifying priority areas for applied research, to explore various combinations of herd potential and level of feeding, the behaviour of different herd sizes and the potential returns from specific technical innovations.     

创新型农村区域环境自主治理模式初探——以四川省彭州市农村环境综合治理为例

文章以四川省彭州市农村环境综合治理社会实践为例,在发动村民群众躬亲躬力、投工投劳自主治理的基础上,构建群众自主治理的框架体系,完善群众"自主管理、自我服务、自我监督"的新型治理模式。     

谈谈喷灌工程的管理与发展

通过对现有喷灌工程的管理进行分析，探讨喷灌工程如何适应当前我国农村经济体制改革与发展的管理问题及新建喷灌工程需要解决的问题，促进喷灌事业的发展。     

Beyond the farm-turn-out: on-farm development dynamics in the Kamphaengsaen irrigation project, Thailand

Many large-scale state-run irrigation projects in the world have been constructed with limited investment in on-farm infrastructure. In most cases, it was expected that local farmers would themselves make improvements on their farms. In general, insufficient attention is paid to water control which has a negative impact on productivity. Farmers' strategies to offset poor access to water are very varied and depend on site-specific factors such as topography, the existence of other potential water sources, market opportunities or capital availability. This article presents a case study in the Central Plain of Thailand and describes the patterns of land development which occurred since the construction of the Irrigation Project 25 years ago. It shows how land and water use evolved as both a mover and a response to on-farm development and who initiated new investments, such as ditch and tube-well digging, regulators in drains, which have allowed secondary water sources to be tapped, the development of conjunctive use, increased reliability in water supply and crop diversification. The importance of individual farm pumps is shown. Poor land levelling is conducive to high costs and reduced water use. Prospects for land consolidation are assessed.     

A regional soil survey approach for upgrading from flood to sprinkler irrigation in a semi-arid environment

Increasing pressure on water resources in Spain is forcing farmers to move from flood to pressurized water application. Initial recommendations for this upgrading require soil survey information, especially in areas prone to soil salinity. In this article a 3158 ha soil survey at a scale of 1:25,000 is presented. Soil series are split in phases based on the texture of the surface layer, slope, and salinity. Available water holding capacity (AWHC), to a depth of 1.5 m or to a lithic or paralithic contact, texture and coarse components in the surface horizons, and salinity mapped as discrete soil units are combined to develop a regional soil suitability map for irrigation upgrade. To minimize soil erosion and salt mobilization in the soils, our recommendations are: (i) maintain and improve flood irrigation on 296 ha, (ii) develop standard sprinkler irrigation on 2261 ha, and (iii) move to high frequency sprinkler irrigation on 601 ha. This research demonstrates the importance of soil survey as part of the decision making process for upgrading the regional irrigation systems.     

Impacts of population growth, economic development, and technical change on global food production and consumption

Over the next decades mankind will demand more food from fewer land and water resources. This study quantifies the food production impacts of four alternative development scenarios from the Millennium Ecosystem Assessment and the Special Report on Emission Scenarios. Partially and jointly considered are land and water supply impacts from population growth, and technical change, as well as forest and agricultural commodity demand shifts from population growth and economic development. The income impacts on food demand are computed with dynamic elasticities. Simulations with a global, partial equilibrium model of the agricultural and forest sectors show that per capita food levels increase in all examined development scenarios with minor impacts on food prices. Global agricultural land increases by up to 14% between 2010 and 2030. Deforestation restrictions strongly impact the price of land and water resources but have little consequences for the global level of food production and food prices. While projected income changes have the highest partial impact on per capita food consumption levels, population growth leads to the highest increase in total food production. The impact of technical change is amplified or mitigated by adaptations of land management intensities.     

非常规水资源农业利用现状及研究进展

由于缺乏合理的水资源管理措施和适当的水处理技术导致淡水资源枯竭和水质恶化问题日益严重,促使再生水、微咸水和雨水等非常规水作为一种新的水资源开发利用方式得到发展,为农业灌溉提供了可靠且稳定的补充水源。然而,非常规水独特的水质特性决定了其农业利用过程中必然会对环境和健康产生众多负面影响,这也成为人们关注的焦点。本文概述了国内外非常规水资源在农业中的利用与研究现状,总结了非常规水资源农业回用的生态风险和相关标准规范,并对非常规水资源农业利用的安全性和可持续性提出相关建议。     

Rainfall persistence: Detection,modelling, costs and value of probability information

The basic hypothesis discussed in this paper is that the presence of persistence or bunchiness in rainfall sequences reduces farm profitability. After a review of past investigations into rainfall persistence, statistical tests are shown to indicate positive inter-temporal correlations in excess of seasonality for weekly and monthly precipitation data from three recording stations in the northern Brigalow region of Queensland. A relatively simple procedure is advanced for generating artificial rainfall sequences containing persistence. Simulation experiments with a grazing-property model incorporating this synthesis procedure are used to test the basic hypothesis. Results indicate substantial reductions in both income and the rate of asset accumulation due to persistence in weekly rainfall. Finally, provision of meteorological information on persistence in the form of conditional rainfall probabilities is proposed, and a simulation and decision theory approach is suggested for determining the potential value of such information.     

Agriculture in South Asia and its implications on downstream health and sustainability: A review

Agriculture, a century old practice, has rarely been questioned as it is a necessity for feeding the world's population. With the increase in food requirement, the sustainability of upland agriculture has posed threats to downstream and coastal areas of river basins. In South Asia, the coastal population depends on the lower part of the river basin for their livelihood such as agriculture and aquaculture. There have been numerous occasions where downstream areas have suffered as a consequence of ad hoc agricultural development activities upstream. Problems encountered in the downstream coastal areas include river desiccation, groundwater depletion, water pollution and sedimentation, salinization and salt water intrusion, soil erosion and nutrient depletion, and dynamic changes in the coastal wetland systems. The objective of this paper is to evaluate current agricultural practices, existing problems, and their implications downstream. This would facilitate the adoption of the river basin approach in managing water resources focusing on the South Asian region.     

我国农业可持续发展与农业机械化

通过对我国农业可持续发展主要制约因素、农业机械对淡水资源和耕地资源的保护作用的分析，阐述了旱作农业、节水农业技术的应用，化肥施用、秸秆处理、农药喷施、地膜回收等农业生产环节与农业可持续发展的关系及对机械装备的需求，工程技术措施对农产品加工、农业自然灾害防治、农业资源合理利用和农业环境保护的应用范围和效果。从而得出农业机械化是中国农业可持续发展的必要条件和重要技术手段的结论结论。     

西部地区传统农业改造与现代农业建设的特殊性研究

胡锦涛同志在党的十七大报告中指出,解决好“三农”问题。事关全面建设小康社会大局,必须始终作为全党工作的重中之重。本文认为,区域农业发展的特殊性决定了在今后和相当长的时期内,西部地区必须坚持把发展现代农业、繁荣农村经济作为首要任务,特别是突出农业科技进步,充分利用农业适用技术创新成果和加大农村人力资本投资与积累,逐步突破传统生产要素的边际收益递减规律制约,最终增强农业综合生产和发展能力,通过西部特色农业现代化发展促进现代农业建设。为实现西部地区城乡统筹发展、构建城乡和谐社会以及全面实现小康目标提供基本经济支撑。     

Poverty and biodiversity trade-offs in rural development: A case study for Pujiang county,China

Both, poverty reduction and preservation of biodiversity are high on the global agenda on sustainable development. The relationships between poverty, biodiversity of agro-ecosystems and agricultural development are complex and poorly understood. In this paper, we present an integrated framework for analysis of agricultural development and natural resource management options at agro-ecosystem level, using Pujiang county, in Zhejiang province, China as a case study area to perform the analysis. A regional linear programming (LP) model is applied, maximizing regional economic surplus, given production and labour market conditions in Pujiang. We use the model to examine the consequences for a set of regional poverty and biodiversity indicators, of four so-called poverty reduction strategies, i.e., (i) intensification of production, (ii) diversification towards livestock production, (iii) land expansion, and (iv) an exit from agriculture. The analysis indicates that diversification is the most promising poverty reduction strategy, but requires efficient use of animal manure in cropping systems to avoid environmental problems. Improved nutrient management in cropping systems is effective in reducing the regional nitrogen surplus, but less effective in increasing per capita income. The exit strategy is effective in reducing poverty and achieving biodiversity goals, but may have important social consequences that are not addressed in this study. Further reduction in rural poverty is hampered by labour constraints during the harvesting period in high value crops such as vegetables and fruits, which calls for research and development in the field of agricultural mechanization.     

Smallholder farmers and forestry development: A study of rural land use in Bendel,Nigeria

The supply of forest products has lagged behind the demand in Bendel State, Nigeria. This derives from unplanned growth of wood-based industries and low capital input in afforestation programmes. Another reason has to do with the general misconception that the supply of timber to wood-based industries is solely a government venture. In the face of these problems, forest regeneration efforts within the reserves could not keep pace with the rate of timber exploitation. It is on the basis of the foregoing deficiencies of wood supply that the land outside reserve boundaries forms an alternative source of timber production.The study described in this paper explored ways of integrating tree planting into the traditional farming system. Data were collected through a questionnaire survey. A sampled population of 300 rural farmers was randomly selected from 32 settlements in Bendel State.Available data indicate high prospects for wood production by the smallholder farmers. This form of land use is favoured by the land tenure system, willingness of farmers to plant trees and the long fallow periods of between 6 and 12 years. However, successful adoption of tree planting relies heavily on cost-sharing devices between government and rural farmers, virile extension services and the possibility of free crops to generate cash flow.     

金东地区设施农业的发展现状、问题及对策研究

为了发挥设施农业在促进农民增收和农村产业结构调整中的作用,本文在分析金华市金东区设施农业发展现状和存在问题的基础上,结合当地农业生产实际,提出了促进金东区设施农业发展的相关措施与建议。     

A simplified modelling approach for pesticide transport in a tile-drained field: The PESTDRAIN model

The paper presents a simplified model called PESTDRAIN. It simulates pesticide transport in a subsurface tile-drained field. It computes surface runoff and tile-drainage flow rates, along with the associated pesticide concentrations, with a variable event-driven time step. PESTDRAIN consists of three coupled modules: SIDRA, SIRUP and SILASOL. SIDRA and SIRUP are the water flow simulation modules in the saturated and unsaturated zones, respectively. SIDRA follows a simplified physically based approach while SIRUP follows a conceptual capacitive approach. SILASOL is the solute transport module for both the saturated and unsaturated zones and is based on transfer functions. It includes simple representations of adsorption and degradation of pesticides.PESTDRAIN was tested on field data sets collected for three drainage seasons at the La Jaillière experimental site in north-western France, for the wheat herbicides isoproturon (IPU) and diflufenican (DFF). After model calibration, relative errors for drainage and surface runoff flows over the season were 14% and 4%, respectively, and the Nash-Sutcliffe efficiency coefficient (N_eff) value for drainage discharge was 0.58. A fair reproduction of a high temporal resolution IPU concentration data set in drainage discharge was also obtained (N_eff=0.28). For the validation data sets, PESTDRAIN was able to simulate accurately drainage discharge with Nash-Sutcliffe efficiency coefficients of 0.57 and 0.69. The global N_eff was 0.44 for all flow-weighted average weekly concentrations in drainage. Relative errors for the pesticide losses were 2.5% and 35% (IPU), and 60% (DFF). For surface runoff the results were not as accurate, but they remained correct in terms of time location and order of magnitude. Although further validation is necessary with more field data, PESTDRAIN appears as a promising tool for agricultural water management.     

华北地区节水型农业分区和发展预测

为因地制宜地指导华北地区节水型农业的健康发展,按照＂归纳相似性、区别差异性、照顾行政区界＂的原则,以地貌特征、气候特征、灌溉程度、缺水程度作为分区指标,将华北分为１０个节水型农业分区;根据农业生产发展的需要,采用系统工程方法,对２０００年华北地区节水型农业发展规模进行了预测。