Water use and technical efficiencies in horticultural greenhouses in Tunisia

We measure the technical efficiency of unheated greenhouse farms in Tunisia, and propose a measure for irrigation water use efficiency (IWUE) using an alternative form of the data envelopment analysis (DEA) model. Technical efficiency measures the degree to which (all) farm inputs are used efficiently. IWUE is a measure of the efficiency of irrigation water use when other inputs and output are kept constant. As a second stage, a tobit model is used to identify the degree to which technical efficiency and IWUE correlate with a set of explanatory variables. A comparison of the efficiency scores obtained from constant returns to scale (CRS) and variable returns to scale (VRS) specifications shows that most farmers in our sample are producing at an efficient scale. Under the CRS assumption, the average technical efficiency of the sample was 67.3%. A similar pattern of scores was shown for IWUE; although in this case the average IWUE was even lower (42%). This implies that when all other inputs remain constant, the current output could be produced using, on average, 58% less irrigation water. We conclude that farmers’ technical training in greenhouse management, investments in water saving technologies and the existence of a fertigation technique on farm have a significant and positive effect on their level of IWUE. However, IWUE is significantly and negatively affected by the proportion of total farm land allocated to greenhouses.     

Impact of resources and technology on farm production in northwestern China

Analyses were performed to evaluate the impact of resources and technological inputs on farm production in northwestern China, including five provincial districts of Shaanxi, Gansu, Ningxia, Qinghai, and Xinjiang. The gross value of farm production using 1978 constant prices was chosen to be the dependent variable in data analysis. Input variables included the irrigation ratio, farm labour, fertilizer application, and farm machinery. Multivariate statistical analysis (correlation and regression) was used to characterize the relationships between the gross value of farm production and various input variables. The gross value of farm production in the region increased fivefold during the study period, and was strongly associated with resource use and technological inputs. The gross value of farm production was significantly correlated with the irrigation ratio in Shaanxi, Gansu, and Ningxia, where the irrigation ratio was relatively low compared with the national averages. The increase in irrigation ratio in these provincial districts explained 9–19% of the growth in farm output from 1978 to 1998. Technological inputs of chemical fertilizer and farm machinery were significantly associated with farming output in all provincial districts. During the study period, the application of technological inputs increased two to eightfold, and contributed about 45% in the growth of farming output in the region. Farm production was also found to be significantly correlated with labour input. Results of this study indicated that water use efficiency and irrigation management need to be improved for future agricultural development, and further advances in farm mechanization and technology application are key for increasing farm production with limited water resources in this semi-arid area.     

精细农业技术的发展与思考

从精细农业的3个技术体系出发,简要介绍了国内外在信息采集系统、信息处理系统与智能化的农业机械方面的发展概况.通过对比分析各种设备、技术及方法在这3个体系中的具体应用,指出了各自的优缺点.认为我国现阶段所进行的研究基本集中在大型国有农场或精细农业示范园区,忽视了集约化程度低、分散经营的农业生产实际,指出应切实结合我国国情,在引进消化国外先进技术的基础上,研制开发具有自主知识产权、低成本的技术成果.     

The analysis of agricultural distribution systems

The application of systems analysis to the study of agricultural distribution has far-reaching implications for marketing investigations and for managerial decision-making. Concepts developed in the emerging discipline of Physical Distribution Management are applicable to agricultural distribution, an area which has not hitherto been the subject of a systems approach which incorporates such concepts as ‘total distribution analysis’, ‘socio-technical systems’ and ‘synergy’. This paper demonstrates the scope for taking a systems analysis view of agricultural distribution and illustrates three of its aspects—namely, the marketing of farm inputs, the distribution of farm produce and machinery management on the farm.     

Improving water use efficiency as part of integrated catchment management

Sustainable agricultural development requires technologies and practices that make more efficient and productive use of resources and an enabling environment that encourages the adoption of these technologies. Many institutions and international agencies are showing considerable interest in integrated catchment management (ICM) as a practical means of improving the management of water resources, reducing environmental degradation and promoting sustainable agricultural development. This paper outlines some of the main components of ICM and lists some of the prerequisites for establishing collective responsibility for, in particular, groundwater resources. This paper also discusses the extent to which programmes of ICM can be used as a means of conserving water resources and improving water use efficiency and productivity at the farm and catchment scales.     

日本精确农业的研究现状

精确农业作为基于知识的农业技术体系，被认为是实现农业可持续发展的先进生产方式。本文介绍了日本在精确农业领域的现状，并针对我国的精确农业研究提出几点思考与建议。     

Crop management based on field observations: Case studies in sugarcane and coffee

For millennia farmers have continually improved their crop management and production practices through their observations and experience. More recently modern science and research methods based on controlled experiments became the most visible instrument of technological change in agriculture, nevertheless farmers continued to develop and implement new technologies based on their own observations made under commercial conditions. Modern information technology and social organization of producers make it possible to use operational research, which is based on the observation and analysis of operations so as to improve them, to manage crops better. The article describes two cases, coffee and sugarcane, in which observation of the results obtained by farmers, with the natural variation in the environment and the distinct management practices they apply can be used to determine site specific crop management practices. The basis of the methodology is to (a) obtain data from a series of cropping events that characterizes the conditions under which each crop is grown, how it is managed and how it performs under commercial conditions (data capture), (b) to manage and analyze the data in centralized databases (data management and analysis) and (c) make the information derived from the data analysis available to growers so that they can use it to make better informed decisions (interpretation). All aspects of the methodology depend on the social organization of the growers and the supply chain of which they form a part, and hence social organization is an integral part of the methodology.The processes of characterization of the growing conditions, including both environmental and management parameters, the establishment of databases, the data analysis and interpretation, and mechanisms of interacting with producers are described with emphasis on the importance of social organization and farmers’ groups. Examples are given of how this approach can be used to better understand the crop response to variation in the environment and management, and how this can be used by farmers to improve productivity and quality in two contrasting crops. The paper demonstrates that operational research can be used to evaluate farmers’ experiences and to share that knowledge amongst them so as to improve their production practices in the context of their particular environment. It is suggested that the operation research approach is particularly effective in heterogeneous landscapes with perennial crops that have not been the subject of intense research. Furthermore operational research is effective in determining the crop response to variables that are not readily studied in small plots and in determining optimal combinations of multiple variables. Producers believe in the results obtained as there are none of the problems of scaling up from experimental plots to commercial conditions. It is proposed that the approaches described can readily be applied to other crop species.     

北京市农业机械化技术发展现状

北京市农业发展以高新技术型、集约化、标准化、生态化的都市型现代农业为目标,建设农业机械化全国农机科技新高地。采用走访调研、文献资料对比分析等方法,将北京市目前拥有的农业机械分为生态、粮经、蔬菜、林果、畜牧养殖、水产养殖、农产品初加工七大产业类,论述各产业机械化技术发展现状,研究各自的发展特点,总体处于减速稳定、减量提质发展阶段。目前存在区域、产业间不均衡,装备结构性过剩,利用率低,先进智能农机装备发展不足等问题。未来发展趋势是生态农业、绿色农业、智慧农业等方面智能化技术及装备的推广应用。以农机农艺融合、机械化信息化融合为发展方向,提供全程机械化技术装备集成技术方案,提高薄弱环节农机装备水平。     

Characterising rice-based farming systems to identify opportunities for adopting water efficient cultivation methods in Tamil Nadu, India

Efficient water use in rice cultivation is a prerequisite for sustaining food security for the rice consuming population of India. Novel rice production practices, including water-saving techniques, modifications in transplanting, spacing, weeding and nutrient management, have been developed and shown to be effective on farm, but adoption of these techniques by farmers has remained restricted. Potential constraints include technical difficulties with new practices, and labour and gender issues which differ between farms. On the basis of a rapid survey of 100 rice-based farms, four farm types were identified based on their socio-economic and biophysical characteristics. Detailed farm surveys were conducted on three representative farms of each farm type to evaluate land use patterns, use of inputs such as water, labour, nutrient, capital and machinery, income from crop and animal production and off-farm activities. Opportunities exist for one or more new rice cultivation techniques to be adopted in all the four farm types. For all farm types, however, the opportunities for use of water-saving irrigation were the least promising. In general, adoption of water-saving irrigation will not improve farmers’ livelihoods despite its importance in reducing water scarcity problems at regional scale. At farm scale, the potential for adoption of water-saving irrigation depends on the season, location of fields and the irrigation source. Changes in government policies such as rules and regulations, pricing, institution building and infrastructure development, as well as training and education of farmers are needed to improve the adoption of modified methods for rice cultivation.     

Typology of cereal-sheep farming systems in Castile-La Mancha (south-central Spain)

There is still no pan-European assessment of the typology of low-intensity farming systems and of the changes which they are undergoing under current European Union (EU) farm policy. This study examines the variability of farm structure and farming practices of a typical cereal-sheep farming system under continental Mediterranean conditions with the aim of providing regional data of policy relevance. The collection of quantitative and qualitative data was planned with collaborative effort from regional extension agencies and followed the Delphi technique. Arable land in Castile-La Mancha occupied more than 70% of total agricultural land in 1997, the rest being natural pasture, shrub-steppe, and Mediterranean forest. Dry low-intensity arable systems still included a sizeable proportion of fallow to cropped land (20%) or somewhat more than 1,000,000 ha, and the winter cereal stubble was often grazed by sheep. These systems were of low intensity in the sense that they used low inputs per ha, particularly of nutrients and agrochemicals. They involved the exploitation of land, particularly for grazing, on an open and large scale. In this sense, they can also be considered extensive systems. On average, only 20% of arable farmers kept sheep, while 80% of the sheep producers were landless pastoralists. Young farmers tend to be disinclined to became involved in the sheep sector, because of the harsh working conditions of sheep farming operations. Response to new economic circumstances involved the evolution of traditional practices with corresponding lower use of farm labour. Although still low-intensive, these systems can be considered as modified forms of traditional practices which have responded to new technologies and the need to cut labour costs. The new objectives for agriculture in Castile-La Mancha, must create or maintain a way of life that is socially and economically attractive to young farmers, without the acceptance of environmentally damaging practices. These new objectives will require a new regionally-targeted EU aid scheme. In turn, there is a need to understand regional agriculture systems before we can hope to achieve successful policy.     

Tools for optimizing management of spatially-variable fields

Efficient use of agro-chemicals is beneficial for farmers as well as for the environment. Spatial and temporal optimization of farm management will increase productivity or reduce the amount of agro-chemicals. This type of management is referred to as Precision Agriculture. Traditional management implicitly considers any field to be a homogeneous unit for management: fertilization, tillage and crop protection measures, for example, are not varied within a single field. The question for management is what to do when. Because of the variability within the field, this implies inefficient use of resources. Precision agriculture defines different management practices to be applied within single, variable fields, potentially reducing costs and limiting adverse environmental side effects. The question is not only what and when but also where. Many tools for management and analysis of spatial variable fields have been developed. In this paper, tools for managing spatial variability are demonstrated in combination with tools to optimize management in environmental and economic terms. The tools are illustrated on five case studies ranging from (1) a low technology approach using participatory mapping to derive fertilizer recommendations for resource-poor farmers in Embu, Kenya, (2) an example of backward modelling to analyze fertilizer applications and restrict nitrogen losses to the groundwater in the Wieringermeer in The Netherlands, (3) a low-tech approach of precision agriculture, developed for a banana plantation in Costa Rica to achieve higher input use efficiency and insight in spatial and temporal variation, (4) a high-tech, forward modelling approach to derive fertilizer recommendations for management units in Zuidland in The Netherlands, and (5) a high-tech, backward modelling approach to detect the relative effects of several stress factors on soybean yield.     

Combining remote sensing-simulation modeling and genetic algorithm optimization to explore water management options in irrigated agriculture

We present an innovative approach to explore water management options in irrigated agriculture considering the constraints of water availability and the heterogeneity of irrigation system properties. The method is two-folds: (i) system characterization using a stochastic data assimilation procedure where the irrigation system properties and operational management practices are estimated using remote sensing (RS) data; and (ii) water management optimization where we explored water management options under various levels of water availability. We set up a soil–water–atmosphere–plant model (SWAP) in a deterministic–stochastic mode for regional modeling. The distributed data, e.g. sowing dates, irrigation practices, soil properties, depth to groundwater and water quality, required as inputs for the regional modeling were estimated by minimizing the residuals between the distributions of field-scale evapotranspiration (ET) simulated by the regional application of SWAP, and by surface energy balance algorithm for land (SEBAL) using two Landsat7 ETM+ images. The derived distributed data were used as inputs in exploring water management options. Genetic algorithm was used in data assimilation and water management optimizations. The case study was conducted in Bata minor (lateral canal), Kaithal, Haryana, India during 2000–2001 rabi (dry) season. Our results showed that under limited water condition, regional wheat yield could improve further if water and crop management practices are considered simultaneously and not independently. Adjusting sowing dates and their distribution in the irrigated area could improve the regional yield, which also complements the practice of deficit irrigation when water availability is largely a constraint. This result was also found in agreement with the scenario that water is non-limited with the exception that the farmers have more degrees of freedom in their agricultural activities. An improvement of the regional yield to 8.5% is expected under the current scenario.     

A method for exploring sustainable development options at farm scale: a case study for vegetable farms in South Uruguay

The methodology presented in this paper aims at analysing whether there is room for improvement of vegetable farmers’ income in Canelón Grande (Uruguay), while reducing soil erosion and improving physical and biological soil fertility, and to gain insight in the influence of farmers’ resource availability on the opportunities for sustainable development. The (generic) approach we developed to support re-design of farming systems in this region is unique in dealing with complex temporal interactions in crop rotations and spatial heterogeneity on farms in one integrated method, while revealing trade-off between economic and environmental objectives. Rather than an arbitrary sub-set, all feasible crop rotations were generated, using a tool named ROTAT. The crop rotations were combined with a range of production techniques according to pre-defined design criteria to create a wide variety of alternative production activities at the field scale. We used process-based simulation models supplemented with empirical data and expert knowledge to quantify inputs and outputs of production activities. We developed a mixed integer linear programming model (MILP), named Farm Images, to allocate production activities to a farm with land units differing in soil quality, while maximising or minimising socio-economic and environmental objectives, subject to constraints at the farm level. Production activities comprised current practices as well as activities new to the area. We used Farm Images to design farm systems for seven existing farms in Canelón Grande with different resource availability. The farm systems designed by the model had higher family income than current systems for six of the seven farms studied. The estimated average soil erosion per ha decreased by a factor of 2–4 in the farm systems proposed compared to the current systems, while the rate of change of soil organic matter increased from negative in the current systems to +130 to +280 kg ha⁻¹ yr⁻¹ in the proposed farm systems. The degree to which the objectives could be achieved was strongly affected by farm resource endowment, i.e., particularly by the fraction of the area irrigated, soil quality and labour availability per ha. The study suggests that decreasing the area of vegetable crops by introducing long crop rotations with pastures and green manure during the inter-crop periods and integrating beef cattle production into the farm systems would often be a better strategy than the actual farmers’ practice.     

Analysis of nitrate pollution control policies in the irrigated agriculture of Apulia Region (Southern Italy): A bio-economic modelling approach

Nitrate leaching is one of the many forms of environmental pollution resulting from irrigation and intensive agriculture. In this work, a method of combining an agronomic simulation model (EPIC) and a mathematical multi-objective programming model is used to analyse the effects of three agricultural policies on farmer’s revenue and nitrate leaching. An evaluation of the net social costs associated with the different policy measures is also given. The farmer’s behaviour in different policy scenarios was studied in terms of selected crops, irrigation technique and method, and adopted management practices with focus on farm management practices and water application efficiency. Irrigation water pricing, subsidies to adopt improved management levels, and taxation on the use of nitrogen fertilizer were examined. A trade-off emerges between the levels of nitrate leaching and net farmer’s revenue more pronounced for nitrogen tax policies than for water pricing. The results obtained indicate that nitrate leaching can be reduced by about 40% with an associated net social cost of 269 €/ha for the water pricing policy, 183 €/ha for the tax on fertilizer and 95 €/ha for subsidies to high efficiency management.     

Simulation model for dryland crop production in the canadian prairies

Modern commercial agriculture is characterised by rapid technological change. These new technologies complicate decision-making for farm managers. Effective decision-making in this environment requires a systematic means of evaluation—one that attempts to evaluate the consequences of various management and production choices before resources are committed. The systems model described in this paper is considered to be an important step in this direction. The model provides a means for testing new production alternatives for cereal and oilseed crops in western Canada without actual farm application and thus of eliminating some of the trial and error associated with conventional decision-making methods. It does not replace the farm manager as the decision maker but it does provide information to facilitate his management function.     

深化农机改革坚持农业可持续发展

深化农机改革是我国现代农业的重要组成部分。本文简述了我国发展农业机械化的同时,也要重视自然资源的合理开发和利用;提出了农机改革的发展战略及科学的农机管理机制,坚持农业可持续发展,保持健康协调的生态环境。     

农机大户经营中面临的困境及解决对策

农机大户在农业机械化发展中发挥着主导作用,为我国农业现代化的发展做出了积极贡献。随着农机大户的纷纷涌现和作业管理规范的缺失,农机大户在经营过程中遇到了很多困难,如何破解这些难题,找到发展对策是值得研究的新课题。分析了当前农机大户经营面临的困境,提出了几点解决对策。      

鹤壁市数字农业发展现状与建议

鹤壁市在数字农业建设方面探索了模式，创新总结了经验，但在数字农业建设和应用方面还存在资源整合不充分、新技术应用不足、系统建设滞后、示范带动作用不强等问题。围绕如何紧跟国家战略、用活上级政策、强化顶层设计，将信息技术深入赋能农业生产、农业经营、农业管理和农业服务，打造数字农业建设“鹤壁模式”，按照“13456+N”的架构进行规划建设，进一步探索服务农业农村高质量发展，全面推进生产智能化、经营网络化、管理数据化、服务在线化。