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91.
Two participatory approaches to varietal selection were compared in February-sown (Chaite) rice and main-season rice in high potential production systems in Nepal. One method, called farmer managed participatory
research (FAMPAR), was researcher intensive, while the other, called informal research and development (IRD), demanded fewer
resources. The trials were conducted in 18 villages in high potential production systems in Chitwan and Nawalparasi districts
of Nepal. Six new varieties of Chaite rice and 16 of main-season rice were tested in over 300 trials of Chaite rice and nearly 1100 trials of main-season rice over two years in 1997 and 1998. Surveys were done in 1997, 1998 and 1999
to record the extent of adoption and spread of the new rice varieties in the study villages. In many cases, farmers tested
varieties for two years before deciding whether to adopt or drop them. Varieties were quite
widely accepted, adopted for niches in a few villages, or rejected. The two participatory approaches identified the same varieties,
but FAMPAR, which used formal survey methods, was more useful for diagnosing reasons for adoption or rejection. However, IRD
used much cheaper anecdotal methods of evaluation, so it was more cost-effective. Moreover,farmer-to-farmer seed dissemination
was higher in IRD villages, probably because farmers in FAMPAR villages felt that the project would re-supply seed if needed.
The benefits from both approaches are considerable, but to adopt them substantial policy changes in varietal testing, release
and extension systems will be required.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
92.
Identification of a diverse mini‐core panel of Indian rice germplasm based on genotyping using microsatellite markers 下载免费PDF全文
Kapil K. Tiwari Anshuman Singh Sasmita Pattnaik Maninder Sandhu Sukhdeep Kaur Sourabh Jain Sushma Tiwari Shweta Mehrotra Mahender Anumalla Rashmita Samal Jyoti Bhardwaj Neha Dubey Vikrant Sahu Gayle A. Kharshing Patu K. Zeliang Kadiri Sreenivasan Pankaj Kumar Swarup K. Parida Sevanthi V. A. Mithra Vandana Rai Wricha Tyagi Pawan K. Agrawal Atmakuri R. Rao Arunava Pattanayak Girish Chandel Ashok K. Singh Ishwari S. Bisht Kangila V. Bhat Gundimeda J. N. Rao Jitendra P. Khurana Nagendra K. Singh Trilochan Mohapatra 《Plant Breeding》2015,134(2):164-171
Identification of a small core germplasm set representing the available genetic diversity is essential for its proper evaluation and subsequent utilization in rice improvement programmes. For constituting a small diverse mini‐core panel of Indian rice germplasm, a representative set of 6912 accessions drawn based on their geographic origin from the whole rice germplasm collection available in the National Gene Bank was genotyped using 36 microsatellite markers. Automated fragment analysis of amplicons yielded a total of 435 alleles, with an average 12.4 and range of 3–29 alleles per locus. Polymorphism information content (PIC) ranged from 0.08 (RGNMS190) to 0.86 (RM552) with an average of 0.528. Based on genotyping data, a mini‐core consisting of 98 genotypes was identified. Ninety‐four per cent of the alleles present in the core set were present in the mini‐core. The identified small but diverse panel will be useful for further intensive trait‐specific evaluation and utilization in allele mining. 相似文献
93.
Juha I. Uitto 《Asia Pacific viewpoint》2005,46(2):143-151
Abstract: This article focuses on a significant paradigm shift in the approaches to biodiversity conservation in the developing countries that has affected important international organisations, including the Global Environment Facility (GEF). This paradigm shift marks a movement beyond protected areas to production landscapes. It is argued that one particular project, People, Land Management and Environmental Change (PLEC), developed under the leadership of Harold Brookfield has contributed significantly to the shift. The project was instrumental in introducing the term ‘agrodiversity’ that encompasses biological diversity as well as the management diversity found in smallholder agricultural systems at all levels. The article describes the evolution of PLEC into a major international collaborative project funded through the GEF. It highlights the project's main achievements and its influence on the policy‐making in the GEF relying on the findings of independent evaluations. 相似文献
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Jumpei Toriyama Tsuyoshi KatoChairil Anwar Siregar Harris Herman SiringoringoSeiichi Ohta Yoshiyuki Kiyono 《Forest Ecology and Management》2011,262(9):1659-1667
Soil carbon (C) stocks in forest ecosystems have been widely estimated to a fixed soil depth (i.e., 0-30 cm) to clarify temporal changes in the C pool. However, surface elevations change as a result of compaction or expansion of the soil under forest management and land use. On the other hand, the calculation of soil C stocks based on “equivalent soil mass” is not affected by compaction or expansion of forest soil. To contribute to the development of a forest C accounting methodology, we compared changes in soil C stocks over 4 years between depth- and mass-based approaches using original soil data collected at 0-30 cm depths in young plantations and secondary forests in West Java, Indonesia. Our methodology expanded on the mass-based approach; rather than using one representative value for the mass-based calculation of soil C stocks, we adjusted individual values, maintaining the coefficient of variance in soil mass. We also considered the effect of an increase or decrease in soil organic matter on equivalent soil mass. Both increasing and decreasing trends in soil C stocks became clearer when the mass-based approach was used rather than the depth-based approach. The trends in soil C stocks based on equivalent soil mass were particularly evident in the surface soil layers (0-5 cm) and in plantation sites, compared with those for soil profiles including subsurface soil layers (0-30 cm) and in secondary forests. These trends in soil C stocks corresponded with temporal trends in litter stocks. We suggest that equivalent mass-basis soil C stock for the upper 30 cm of soil be calculated based on multiple soil layers to reduce estimation errors. Changes in soil organic matter mass had little effect on the estimation of soil C stock on an equivalent mass basis. For the development of a forest C accounting system, the mass-based approach should be used to characterize temporal trends in soil C stocks and to improve C cycle models, rather than simpler methods of calculating soil C stocks. These improvements will help to increase the tier level of country-specific forest C accounting systems. 相似文献
97.
基于社区的生态林业规划方法研究 总被引:1,自引:0,他引:1
笔者基于社区进行研究,以参与式农村评估技术(PRA)和参与式地理信息系统(PGIS)为工具,通过了解沙坪村的概况,制订合理的研究方法。经过准备阶段、现状的调查分析、树种选择,最后完成该地区的生态林业规划方案。结果表明,基于社区的生态林业规划方案,可有效地促进社区村民、规划人员等不同利益群体之间的沟通,规划方案符合当地的经济和社会发展状况。 相似文献
98.
99.
Urbanization and coastal development has dramatically reduced the beach habitat available for foraging shorebirds worldwide. This study tested the general hypothesis that recreational use of shorebird foraging areas adversely affects the foraging behavior of sanderlings Calidris alba. Observations conducted on two central California beaches from January through May and September through December of 1999 showed that number and activity of people significantly reduced the amount of time sanderlings spent foraging. Although the sample size was low, the most significant negative factor was the presence of free running dogs on the beach. The experimentally determined minimal approach distance did not vary significantly with the type of human activities tested. Based on these results, policy recommendations for minimizing the impact of human beach activities on foraging shorebirds include: (1) people maintain a minimum distance of 30 m from areas where shorebirds concentrate and (2) strict enforcement of leash laws. 相似文献
100.
降水资源高效转化利用对于提高早地农业和灌溉农业生产综合效益均具有重要意义。通过对黄土区农田作物降水利用效率的概念及其影响因素、农田降水生产潜力等相关研究成果的分析,从实现土壤水库扩蓄增容、增加农田地面覆盖、促进作物根系生长、减少作物无效蒸腾、持续增加土壤肥力等5个方面,提出了提高黄土区农田降水利用效率的方法和途径,并结合降水资源转化利用技术发展需求,提出了近中期提高降水资源利用效率技术的发展方向和研发的若干重点。 相似文献