共查询到20条相似文献，搜索用时 249 毫秒
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《绿色科技》2019,(22)
为了客观全面地了解国内应用生物炭对农田土壤改良的现状和动态以及未来的主要发展趋势,基于中国知网数据库,对有关生物炭改良农田土壤的相关文献进行了检索与分析。结果表明:我国生物炭改良土壤方面的研究从发文量来看正处于快速发展阶段;我国生物炭改良土壤领域的研究,发文量最多的机构是西北农林科技大学,被引频次最多的也是西北农林科技大学;发文量最多的是华中农业大学姜存仓教授,被引频次最多的则是西北农林科技大学何绪生教授。该领域的研究主要以国家层面的基金资助为主,占到了72.33%;生物炭改良土壤研究的热点研究主要集中于土壤改良、土壤养分、重金属修复等方面,这也是生物炭用于土壤改良未来的主要研究方向。 相似文献
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人工林地力衰退研究现状与进展 总被引：3，自引：0，他引：3
介绍了国内外人工林地力衰退的历史背景和现状,从人工林群落结构、土壤微生物种群区系、土壤理化性质和生化特性,栽培措施等方面分析了导致人工林地力衰退的原因,提出了调整林分结构,保护林下植被、混交,林地施肥和土壤改良、科学营林等措施防止地力衰退;概述了人工林地力衰退的研究进展和今后研究方向。 相似文献
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林业除草是营林生产过程的重要环节,美国孟山都公司研发的林用除草剂草甘膦以其杀草广谱、内吸传导性强的优势在林业生产中被广泛采用。然而随着草甘膦的过量使用,残留在林地土壤中的草甘膦势必增加,不仅作用于靶生物以防除杂草,而且对非把生物也产生影响,导致林地生态系统结构改变,功能遭受破坏。近年来,虽然国内外学者对草甘膦在农业应用的环境行为和生态风险进行了大量研究,但对于草甘膦在林业上的研究鲜见报道。文中从草甘膦的除草机理、在林地土壤中的环境行为、林用生态风险以及合理使用等方面综述了草甘膦在林业应用中的研究进展,以期为人工林经营过程中草甘膦的合理使用提供科学参考。 相似文献
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《内蒙古林业调查设计》2017,(4):92-94
在现今酸性土壤改良过程中,生物炭的众多特性使得其拥有良好的前景。文章以近年来的研究成果为事实依据,通过举例说明、对比说明等方法,从生物炭对酸性土壤的PH、养分、结构以及持水能力等方面的改良途径及原理进行阐述及探讨。最后总结生物炭目前存在的争议以及对生物炭未来发展方向,进行了进一步的展望。 相似文献
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人工林可持续经营研究进展 总被引：1，自引：0，他引：1
人工林可持续经营问题已经成为林学家关注的焦点,也是中国人工林发展亟待解决的问题。人工林可持续经营问题十分复杂,笔者从地力维护、林分结构调控和人工林近自然经营等方面对人工林可持续经营技术研究做了综述。同时分析了人工林可持续经营研究中存在的问题以及人工林可持续经营研究的发展趋势。 相似文献
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The nearly complete removal of forest cover from China's northern plains before the renewal of household incentives and subsequent reforestation in the late 1970s provides an unusual broad-scale opportunity to examine the impact of forest-based environmental services on long-term agricultural productivity. This paper uses a Cobb-Douglas agricultural production function with a measure of forest cover as a production shifter to test the hypothesis that forest-related environmental services make a positive contribution to agricultural output. Our evidence for Shandong province shows that agroforestry activities rapidly produced approximately ten percent increases in agricultural productivity — and their contribution probably has not reached its limit. The relevance of this finding goes beyond China's agriculture to the broader question of how world agricultural production can be sustained in the long-run — after the possible exhaustion of the contributions of current institutions and farming systems. If the opportunities for expanding the agricultural land base and for multiple cropping are small, and if ever more labor must be squeezed into the agricultural sector, then what can contribute to agricultural growth? One answer must lie in improvements to the agricultural environment, and trees may be a part of this improvement. 相似文献
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Chuanqi Yan Weizhang Yang Chunte Li Xiaozong Han Fenglin Ma Wanyun He 《Agroforestry Systems》1989,8(1):83-90
The cutting down of forest and the extension of arable fields led to severe degradation of the land in the Mao Jia Shan valley. In restoring the environment and the agricultural productivity, the intricate ecological relations within and between the diverse types of land utilization are taken into account. Strategies are adopted to the ecological sub-systems, such as arable fields, grassland, orchards, sloping woodland, fish ponds, marshes etc.Within the first 3 years soil erosion was reduced to 1/50th of its previous value and agricultural productivity increased 2.3 fold. Balances of organic matter, N, P and K have been calculated and predicted upto the year 2000. The model, based on the evaluation of fuzzy sets of multiple factors, indicates a further large improvement in productivity and local rural economy. 相似文献
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Joyotee Smith Socorro Ferreira Petra van de Kop Célio Palheta Ferreira Cesar Sabogal 《Agroforestry Systems》2003,58(2):125-135
While slash-and burn farmers convert forest to agriculture, they also regenerate significant areas of secondary fallow forests on their farms. Under what conditions does secondary forest cover persist on slash-and-burn farms? Survey data from Pará, Brazil show that secondary forests occupy 20% of farm area even after a century of settlement. In addition to restoring soil fertility, secondary forests contribute over 20% of farmers' income through products such as charcoal, fruit, game animals and firewood for on-farm processing. Econometric analysis shows that slow rates of population growth and increases in agricultural incomes through on-farm processing of agricultural products enable farmers to maintain long fallows and result in diversified systems compatible with secondary forest cover in the study area. On the other hand, declining agricultural productivity, subsidized credit, declines in the growth rate of secondary forests and policies favoring speculative land acquisition threaten secondary forest persistence. In older settlement areas, secondary forests are often the only forest resource available to the rural poor. Fallow areas should therefore be managed not only for agricultural productivity, but also for conserving forest resources. 相似文献
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对粮食安全下继续推进退耕还林工程的再思考 总被引：1，自引：0，他引：1
对于退耕还林工程对我国粮食安全会产生正向的外部效应还是负面的影响,不同学者提出了迥然不同的观点.文章从退耕还林后对土地利用结构和农村产业结构的优势调整、工程区生态环境的有效改善、农业生产条件得到提高、农业生产要素得到优化配置等方面论述了退耕还林工程不但不会对我国粮食安全造成影响,反而为提高农业综合生产能力提供了外部保障. 相似文献
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土壤在调节地球气候和物质循环方面起着重要作用,但是由于人为因素的影响,不当的土地经营模式（如居民用地、农业耕地、毁林开荒）对土壤质量产生了深刻影响,使土壤质量发生变化。本研究对黑龙江省尚志市帽儿山林场的4种不同的土地利用与经营模式（森林土壤、农田土壤、场部用地和森林迹地）下的土壤理化性质和土壤酶活性进行测定与分析,探讨不同土地利用模式对其土壤理化与土壤酶学特性的影响。研究发现4种土壤类型的10个采样点的10个土壤理化指标和5个土壤酶活性指标间存在显著差异,土壤质量从高到低依次为：森林土壤,森林迹地,林场场部用地,农田用地。相关分析表明土壤脲酶和过氧化氢酶与土壤含水量、土壤全氮、土壤全碳、土壤有机碳、可溶性全碳和可溶性有机碳含量之间成显著正相关;多酚氧化酶与土壤pH成显著正相关。因此,不同土地利用方式对土壤理化性质和土壤酶活性产生显著影响。 相似文献
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随着社会经济的发展,人地矛盾日益尖锐,自然植被遭到严重破坏,土壤严重退化,因此,恢复植被及恢复土壤生态环境,提高森林或人工林生产力,促进森林尽快发挥其经济与生态功能势在必行。为此,本文以自然植被针叶混交林地为参照,同针叶人工纯林地、阔叶人工纯林地、针叶人工混交林地进行比较,探讨不同植被类型土壤物理性状的差异和动态过程,客观揭示土壤物理特性变化与人为干预影响之间的关系。 相似文献
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The Atlantic Forest has been deforested to the point that only about 7% of the original forest remains. Soil degradation, including loss of soil organic carbon (SOC), has often been associated with deforestation. In extensive areas previously occupied by Atlantic Forest the soil has a naturally compact subsoil horizon called the coeso. This layer challenges root development and plant productivity. The purpose of this study was to investigate soil carbon and selected physical characteristics under the influence of the native forest and post-deforestation agricultural practices. The management regimes were a native forest, a rubber tree plantation, a pasture and annual cropping. Two soil depths were investigated: 0 to 15 cm, corresponding to the A horizon; and 35 to 50 cm, corresponding to the coeso. Management influenced both SOC concentration and soil bulk density; however, SOC content was not significantly changed by any of the post-deforestation land uses. This result supports the annual cropping system that has been adapted by small landholders. Most interesting was the quantity of SOC found in the coeso, which was as much as 50% of the surface horizon. 相似文献
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近年来,受国内外经济形势的影响,浙江安吉县的毛竹价格逐年下降,毛竹林的经济效益受到影响,如何提高毛竹林的生产力、培育大径竹材已经成为毛竹林经营的重要内容。毛竹林的生产力与土壤养分密切相关,测定分析了安吉县主要毛竹产区笋材两用林的土壤养分,探讨了竹林经营模式、竹林产出与土壤养分状况的关系。结果表明:安吉县毛竹林土壤普遍缺乏速效钾,而土壤有机质含量较为丰富;竹林平均胸径随土壤速效磷含量的增加而增加。因此,培养大径级竹林应增施磷肥和钾肥。研究结果可为优化毛竹林经营模式、提高竹林产量以及合理制定竹林施肥策略提供依据。 相似文献