共查询到20条相似文献,搜索用时 15 毫秒
1.
This article is a commentary on several research studies conducted on the prospects for aerobic rice production systems that aim at reducing the demand for irrigation water which in certain major rice producing areas of the world is becoming increasingly scarce. The research studies considered, as reported in published articles mainly under the aegis of the International Rice Research Institute (IRRI), have a narrow scope in that they test only 3 or 4 rice varieties under different soil moisture treatments obtained with controlled irrigation, but with other agronomic factors of production held as constant. Consequently, these studies do not permit an assessment of the interactions among agronomic factors that will be of critical significance to the performance of any production system. Varying the production factor of “water” will seriously affect also the levels of the other factors required to optimise the performance of a production system.The major weakness in the studies analysed in this article originates from not taking account of the interactions between experimental and non-experimental factors involved in the comparisons between different production systems. This applies to the experimental field design used for the research studies as well as to the subsequent statistical analyses of the results. The existence of such interactions is a serious complicating element that makes meaningful comparisons between different crop production systems difficult. Consequently, the data and conclusions drawn from such research readily become biased towards proposing standardised solutions for possible introduction to farmers through a linear technology transfer process. Yet, the variability and diversity encountered in the real-world farming environment demand more flexible solutions and approaches in the dissemination of knowledge-intensive production practices through “experiential learning” types of processes, such as those employed by farmer field schools.This article illustrates, based on expertise of the ‘system of rice intensification’ (SRI), that several cost-effective and environment-friendly agronomic solutions to reduce the demand for irrigation water, other than the asserted need for the introduction of new cultivars, are feasible. Further, these agronomic solutions can offer immediate benefits of reduced water requirements and increased net returns that would be readily accessible to a wide range of rice producers, particularly the resource poor smallholders. 相似文献
2.
A major policy concern in irrigation development is reducing government costs of both construction and operation and maintenance. There is increasing interest in shifting some of these costs to the farmers using the irrigation facilities. This paper discusses the opportunities for reducing certain direct costs to government by collaborative arrangements with water users so that the latter mobilize more of their own resources to implement specified O&M activities. Five propositions are discussed which suggest the prerequisites for successful collaboration: (1) reexamining the processes of design and construction now being used, (2) reorienting the policies and procedures of the irrigation agency, (3) increasing farmer involvement in operations, (4) increasing local organizational capacity, and (5) creating new financial procedures. 相似文献
3.
《Agricultural Systems》1987,25(3):229-236
The small farmer, especially in developing countries, requires a system of selective mechanisation due to his peculiar problems of small holdings, low capital, poor technological environment and the constraints inherent in the traditional system of agriculture. The decision facing the small farmer is whether the purchase of available farm machinery will improve his net earnings and how best to utilise this machinery within the limitations of his operational constraints. This paper describes a simple procedure to assist such decision-making. 相似文献
4.
Olaf Erenstein 《Agricultural Systems》2011,104(1):54-62
Conservation agriculture practices are being advocated to help sustain crop productivity gains and secure environmental sustainability in the Trans-Gangetic Plains, India’s Green Revolution heartland. The paper illustrates the use of village surveys as a quasi-quantitative system analysis tool to derive implications for agricultural research and development. Drawing from village surveys in 170 communities, the paper assesses current crop residue management practices in Punjab and Haryana’s rice-wheat, basmati-wheat and non-rice-wheat cropping systems. The prevalence of wheat as the winter crop implies an intensive collection, trading and use of wheat straw as basal feed for dairy livestock; which contrasts with the diverse crop residue management of the monsoon crops. The increased use of combine harvesters has spurred the rapid advent of mechanical wheat straw reapers whereas the bulk of combine harvested rice straw is burned in situ. Present crop residue management practices are largely incompatible with year-round mulch retention despite significant biomass production. The research and development community faces the challenge of evening out straw use and management over seasons to ensure at least partial residue retention if its calls for conservation agriculture in this important sub-region are to succeed. The paper also reiterates the worrying decline of groundwater tables associated with the rice-wheat system. 相似文献
5.
M. C. Smith J. H. Massey J. Branson J. W. Epting D. Pennington P. L. Tacker J. Thomas E. D. Vories C. Wilson 《Irrigation Science》2007,25(2):141-147
Rice irrigation-water use was estimated in Mississippi (MS) and Arkansas (AR) in 2003 and 2004. Irrigation inputs were compared
on naturally sloping (i.e. contour-levee system) and mechanically graded fields. In MS, rice production consumed, on average,
895 mm water, but irrigation inputs were greatly affected by production system. Contour-levee systems accounted for 35% of
the production area and consumed 1,034 mm irrigation. Fields mechanically graded to a consistent slope of approximately 0.1%
(i.e. straight-levee systems) consumed 856 mm irrigation and accounted for 60% of the production area. Fields devoid of slope
(i.e. zero-grade system) accounted for 5% of the production area and consumed 382 mm irrigation. In AR, contour-levee rice
production consumed 789 mm compared to 653 mm with a straight-levee system. Using low pressure, thin wall (9–10 mil) disposable
irrigation tubing to deliver water to each paddy independently reduced irrigation inputs by 28% in MS and 11% in AR when compared
to a single-point (levee-gate) distribution system. 相似文献
6.
David Groenfeldt 《Irrigation and Drainage Systems》1988,2(3):241-257
The management of most irrigation systems involves shared responsibility between one or more government agencies and farmers. Finding the optimal level of farmer management participation is an essential part of achieving optimal system performance. Two cases are discussed where farmers have been encouraged to play a more active management role with promising results. In the Gal Oya system in Sri Lanka, farmers manage the tertiary channels and also have a voice in managing the main system. In the Philippines, small systems have been turned over entirely to farmer management, while on large systems farmers manage the tertiary or secondary levels. A number of factors appear to be important in the management success of these irrigation systems including: -the social environment, -a manageable main system, -a strong commitment by the irrigation agency, -the use of community organizers, and -construction tasks around which farmers can organize. Greater farmer involvement in irrigation management can have both economic and social benefits. Economically there is evidence that farmers perform certain functions better than outside agencies can, and that both farmers and agencies perform their management tasks better when they feel a mutual responsibility for a common objective. Social benefits include the organizational skills that farmers learn and which may be useful in other activities, and a sense of self-respect and self-reliance. Though farmer participation requires a deliberate effort on the part of international and government agencies, as well as farmers, the benefits can be substantial. 相似文献
7.
8.
John L. Dillon 《Agricultural Systems》1976,1(1):5-22
There are three broad aspects of Systems Research worthy of particular consideration by professional personnel earning their keep within or about the agricultural research system. I will discuss these three aspects seriatim. The first is the conjecture that the systems approach constitutes a technological change in our mode of thinking about the world of such magnitude as to imply that we are now moving from one sociotechnical age to another. The second aspect, a corollary of the first, is the use of the systems approach as a framework for the selection of research programmes. The third, which also follows from the first, is the efficiency of conducting research on a systems basis. Many would think of this last aspect of efficiency as constituting ‘the economics of systems research’, but I believe the systems approach, via the first two aspects I have mentioned, has far wider implications of economic import for agricultural research. 相似文献
9.
《Agricultural Systems》1986,22(2):109-125
Some key practical issues in improving the economic impact of farming systems research are examined. Following some general background on how such research evolved, these issues are treated with respect to its three main stages.With the ex ante stage the needs of securing representativeness of the target area and of benchmarking the wider initial situation, including economic, social and agroclimatic features, are emphasized. With the ongoing stage, the importance of using suitable partial budgeting techniques is stressed. With the ex post stage, an assessment of wider technological and economic effects is called for, together with the identification of enabling factors and constraints in technological progress.The adjustment of the farming systems research process itself is finally considered, and the desirability of simplifying the process, further training junior field-level researchers and securing better interaction between workers at the various research levels, is highlighted. 相似文献
10.
文章结合《农民专业合作社法》的学习,探索了如何利用《农民专业合作社法》组建农机农民专业合作社及农机合作社的成立对我国农村经济发展的意义。 相似文献
11.
12.
13.
农民收入决定因素的计量分析 总被引:1,自引:0,他引:1
现阶段我国农民收入主要有农业收入和非农业收入两类,农民收入的提高也主要依赖于这两类收入的增加。对相关数据计量分析的结果显示,在这两类收入当中,从事非农产业获得的收入大大高于农业所得收入,农业收入提高与农业总产值有着很大的关系,而农业总产值的提高则有赖于财政支出以及个人对农业的投入。因此,提高农民收入可以从加大财政、个人对农业的投入和转移农村剩余劳动力从事非农产业中得以实现。 相似文献
14.
15.
16.
17.
《Agricultural Systems》2007,92(1-3):318-333
This paper presents an econometric analysis of the influence of soil fertility status on productivity and resource use in rice production utilizing survey data from 21 villages in three agro-ecological regions of Bangladesh. Detailed crop husbandry input–output data were collected from 380 paddy rice (Oryza sativa) farmers. Data collected included fertilizer, pesticide, labour, animal power services, irrigation, farm capital assets and rice yield. The soil fertility status in each region was determined by analysis of soil organic carbon, available nitrogen, phosphorus and potassium concentration. Analysis was based on a profit function, where the selected soil fertility parameters were incorporated as yield controlling variables. Results revealed that soil fertility has a significant influence on both productivity and farmers’ resource allocation decisions. Output supply was significantly higher in fertile regions and input use was significantly lower. This observation indicates that in policy terms technological initiatives should be targeted at measures to identify areas of lower soil fertility so that inherent soil-based productivity restrictions can be minimized. In part this will be facilitated by the transfer of indigenous knowledge from farmers in higher productivity areas, thus increasing rice production and raising the competitiveness of Bangladeshi rice farmers. 相似文献
18.
赵文峰 《农业装备与车辆工程》2006,(11):51-52
介绍了全国各地养殖户利用牲畜粪便制沼气的传统方式,指出了我国广大养殖户未能使用上就在自己身边的环保实惠清新能源的原因,开发设计了一种对牲畜粪便等物料进行自动上料、密闭储存、搅拌、厌氧发酵和自动清除沼渣的制沼气成套装置,符合我国废物再利用、创建和谐型可持续发展社会的基本国策。 相似文献
19.
B.R. Roberts 《Agricultural Systems》1976,1(3):233-242
The availability of computers has made it possible to process large volumes of complex data. This development has enabled scientists to enter the field of systems research which both analyses and synthesises complex multivariate agricultural production systems. By building models which represent real systems and by simulating the internal processes of each component of the system, systems research can be used in prediction, decision-making, developing new production methods and teaching. The potential use of modelling in the field of pasture science in South Africa deserves careful evaluation, in view of the complexity, expense and long-term nature of traditional grazing experiments. There is a place for modelling by inter-disciplinary teams in local research, in spite of the present shortcomings of this recently-developed approach. 相似文献
20.
Douglas L. Vermillion 《Irrigation and Drainage Systems》1990,4(2):133-150
The paper argues that conventional irrigation design processes rely heavily on predetermined design criteria, often without allowing for interactions with farmers and revising of criteria during implementation. Six cases from a tertiary development project in North Sulawesi, Indonesia are described, where farmers altered what had been designed and constructed by contracting and agency engineers. Through field inspections and farmer interviews, the farmers' alternative set of design criteria was elicited to explain why the farmers changed what had been constructed. A total of 27 cases are analyzed to show the relative importance of:
相似文献
| farmer criteria which are compatible with project criteria but which draw on local knowledge of the environment, |
| farmer criteria which were additional to project criteria and |
| farmer criteria which were incompatible with project criteria. |
| Some mechanisms are suggested for how to incorporate into the design process local knowledge, interactive learning and flexibility. |