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471.
Oluyede Clifford Ajayi Festus K. Akinnifesi Gudeta Sileshi Sebastian Chakeredza 《Natural resources forum》2007,31(4):306-317
Low soil fertility is one of the most important biophysical constraints to increasing agricultural productivity in sub‐Saharan Africa. Several renewable soil fertility replenishment (RSFR) technologies that are based on nutrient re‐cycling principles have been developed in southern Africa. Some success stories have been recorded (e.g. nitrogen‐fixing legumes), but the adoption of RSFR technologies has generally lagged behind scientific advances thereby reducing the potential impacts of the technologies. This paper describes the major RSFR technologies being promoted in the region, synthesizes available information regarding their adoption by farmers, and identifies the challenges, key lessons learnt and the way forward for up‐scaling RSFR technologies in the region. The review indicated that farmer uptake of RSFR technologies depends on several factors that can be grouped into broad categories: technology‐specific (e.g. soil type, management regime), household‐specific (e.g. farmer perceptions, resource endowment, household size), policy and institutions context within which RSFR is disseminated (inputs and output prices, land tenure and property rights), and geo‐spatial (performance of species across different bio‐physical conditions, location of village). Adoption of RSFR technologies can be enhanced by targeting them to their biophysical and social niches, facilitating appropriate policy and institutional contexts for dissemination, understanding the broader context and dynamics of the adoption process, a paradigm shift in the approach to the dissemination of RSFR (e.g. expanding RSFR to high value crop systems, exploring synergy with inorganic fertilizer) and, targeted incentive systems that encourage farmers to take cognizance of natural resource implications when making agricultural production decisions. 相似文献
472.
张丽彬 《中国环境管理干部学院学报》2006,16(3):11-12
乐亭县地处滨海,农业用水效率低,加之上游连年缺水,造成田间荒芜撂荒现象严重.乐亭县是农业大县,工业相对薄弱,掀起一场提高农业用水效率的革命势在必行.主要途径:大力推进节水灌溉制度,调整农业种植结构,积极引进、开发、培育节水高产品种,减少无效蒸发,节水高产施肥、培肥技术. 相似文献
473.
在对黄山市农业气候条件进行调查分析的基础上,编制了气候资料表;并根据当地林、茶、果、桑、药的自然分布状况,结合山区农业气候资源概况,对如何利用山区农业气候资源进行了分析和研究。 相似文献
474.
The challenge of pursuing sustainability in agriculture is often viewed as mainly or wholly technical in nature, requiring the reform of farming methods and the development and adoption of alternative technologies. Likewise, the purpose of sustainability is frequently cast in utilitarian terms, as a means of protecting a valuable resource (i.e., soil) and of satisfying market demands for healthy, tasty food. Paul B. Thompson has argued that the embrace of these views by many in the consumer/environmental movement enables easy co-optation by agribusiness. It also reflects a critical weakness in this movement: a lack of commitment to philosophical principles that depart from the utilitarian premises of the industrial model of agriculture. This paper draws on the writings of Thomas Berry and Liberty Hyde Bailey to identify the philosophical principles of what we call planetary agrarianism. From the perspective of planetary agrarianism, the pursuit of sustainability is a broad and challenging moral, educational, and political task. Berry helps us see that it is fundamentally a project of worldview transition, which requires a new cultural narrative that must rival, in form and appeal, the mythic power of the utilitarian industrial vision. Liberty Hyde Bailey, author of The Holy Earth (1915) and a leader in the land-grant education and nature-study movements, took up the project of worldview transition in his life work. While in some ways dated and flawed, Bailey’s writings are a valuable source of guidance for developing and pursuing a viable philosophy of agriculture for the 21st century. 相似文献
475.
476.
基于污染物的环境污染损失机理性模型,Logistic方程及环境价值的相关理论,建立了环境污染经济损失估算模型。利用此模型估算了2003—2007年某市2条主要河流J河和G河的水污染造成的农业经济损失,并计算了2007年度5种污染物浓度单独增加10%造成的污染损失值。结果表明:近5a来,2条主要河流由于水环境污染造成的农业经济损失逐年增加。 相似文献
477.
上海都市农业可持续发展的定量综合评价 总被引:8,自引:0,他引:8
在借鉴国内外已有相关研究成果的基础上,构建了一套能凸显都市农业特色的可持续发展评价指标体系,选用以层次分析法与信息熵法相结合确定指标权重为核心的数学模型与方法,从时间尺度上对1993年上海自开展都市农业实践以来的都市农业可持续发展进行定量综合评价。结果表明:①人口子系统已逐步成为阻碍都市农业可持续发展的主要因素之一,经济子系统逐渐成为都市农业可持续发展的主要贡献因子,社会子系统对都市农业可持续发展的促进作用越来越大,农地资源短缺且持续减少,制约着都市农业可持续发展能力的提高,农业生产自身污染负荷较重,影响着都市农业可持续发展能力的全面提升;②都市农业可持续发展的R-D综合指数不高,下降趋势明显,都市农业可持续发展的资源压力较大且持续增加,E-D综合指数较低,变化幅度不大,都市农业可持续发展的环境压力大但趋向稳定;③可持续发展综合评价指数经过前期波浪式增减后持续稳步攀升,都市农业可持续发展能力增强态势明显。 相似文献
478.
Akira Watanabe Benito H. Purwanto Ho Ando Ken-ichi Kakuda Foh-Shoon Jong 《Agriculture, ecosystems & environment》2009,134(1-2):14-18
Tropical peatland is a vast potential land source for biological production, but peatland is a major natural source of greenhouse gases, especially methane (CH4). It is important to evaluate the changes in greenhouse gas emissions induced by cultivation practices for sustainable agricultural use of tropical peatland. We investigated the effects of fertilizer application and the groundwater level on CH4 and carbon dioxide (CO2) fluxes in an Indonesian peat soil. The crop cultivated was sago palm (Metroxylon sagu Rottb.), which can grow on tropical peat soil without drainage and yield great amounts of starch. CH4 emission through sago palm plants was first estimated by collecting gas samples immediately after cutting sago suckers using the closed chamber method. The CH4 fluxes ranged from negative values to 1.0 mg C m−2 h−1. The mean CH4 flux from treatment with macroelements (N, P, and K) and microelements (B, Cu, Fe, and Zn) applied at normal rates did not differ significantly from that of the No fertilizer treatment, although increasing the application rates of macroelements or microelements by 10-fold increased the CH4 flux by a factor of two or three. The relationship between CH4 flux and the groundwater table was regressed to a logarithmic equation, which indicated that to maintain a small CH4 flux, the groundwater table should be maintained at <−45 cm. The CO2 fluxes ranged between 24 and 150 mg C m−2 h−1, and were not significantly affected by either fertilizer treatments or the groundwater level. The inclusion of sago palm suckers in a chamber increased CH4 emission from the peat soil significantly. Thus, gas emissions mediated by certain kinds of palm plants should not be disregarded. 相似文献
479.
介绍了大理州南涧县早期生态农业试点成果和近年来的发展状况,认为南涧县长年坚持生态农业建设,依托“高山、净土、生态”优势,走出了一条区域化布局,规模化发展,标准化生产,一体化经营,品牌化导向的发展模式。 相似文献
480.
现代石油农业在取得巨大经济社会效益的同时,生产中化肥、农药的过度使用也引发了严重的环境问题.以中国综合社会调查(CGSS2010)的数据为基础,运用多元线性回归模型分析环境污染认识情况及其影响因素.结果表明,居民对农业环境污染认知处于高认可水平;个体的户口、年龄,社会经济地位的个人年收入和受教育年限,环境感知的环境问题严重程度、环境问题关注程度显著影响居民农业环境污染认知.提出通过引导居民形成高度的环境保护意识来改善农业生产环境,确保食品安全. 相似文献