共查询到18条相似文献，搜索用时 218 毫秒
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三峡库区马褂木水源涵养林复合经营模式研究 总被引：1，自引：0，他引：1
马褂木是重要的绿化、用材和水源涵养林兼用树种.三峡库区栽培面积已超过2 400 hm2.本文通过分析8种复合经营模式的效益,来综合评价不同的复合经营模式.通过对比分析,复合经营的马褂木胸径生长量年均提高10％以上.复合经营的马褂木-桔梗模式、马褂木 白术模式的年收入最高,投入大;而柴胡、黄芪和黑豆投入小、种植技术比较好掌握.试验出的几种模式可减少土壤侵蚀量33.3％,生态效益显著.根据推广应用前景,结合药材市场需求种植,提高土地利用率和单位面积产出,促进林农增收. 相似文献
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农作物与经济林树种间作,称为农林复合经营.农林复合经营可以提高单位面积的经济效益,增加农民收入.对农林复合经营的模式以及农林复合经营在乡村林业中的作用进行了探讨. 相似文献
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林业是农业的生态屏障,为了保障农业稳产、高产,要大力发展农田林网,改善生态,逐步向农林复合系统前进.农林复合生态系统形式多种多样,有树木与农作物轮流种植的模式;有在坡地上成行相间种植的模式;有在农作物中间栽植经济树木的混合种植模式;有在田边地角种植树木和防护林带等,我国三北防护林工程体系的重要内容之一就是农田林网. 相似文献
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系统地研究了农林复合系统对自然资源利用率的影响,结果表明：农林复合系统具有提高资源利用率的功能,但系统内不同模式之间光能利用率差异较大,梨粮复合模式光能利用率比周边种植模式高１０．３％,系统内光能利用率则比旷野平均提高了２５．０％。农林复合系统水分利用率一般可比旷野农田高１０．３％～１５．２％。农林复合模式热量利用效率比一般旷野农田高１１％～１３％。农林复合系统不仅能改善农田生境与提高资源利用效率,还能增加农民的经济收入,可在我国北方平原农区大力推广。 相似文献
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以商丘市梁园区为例,对豫东黄河故道的农林复合生态模式进行了调查研究。结果表明在黄河故道发展农林复合生态系统可以为当地创造一定的经济与生态效益。根据研究地区的自然与社会环境条件,可以发展以下几种农林复合生态模式:①林农复合生态模式,在幼龄林中种植小麦、油菜等喜光作物;②林药复合生态模式,树龄达到4年以后在林下种植耐阴的药用植物;③林牧复合生态模式,林冠完全郁闭之后在林下养鸡等。 相似文献
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笔者运用灰色理论对辽西北3种典型农林复合模式内的代表性因子进行了综合效益比较分析,结果表明:用综合等权指标δ1和侧重生态效益变权指标δ2,侧重经济效益变权指标δ3所得到的评判结果一致,即3种农林复合模式中,大扁杏—花生—玉米的改良效果、生态效益和经济效益最好,樟子松—花生相对较好,大扁杏—麻英草次之。大扁杏—花生—玉米农林复合模式是辽西北地区土地开发利用、土壤改良、水土保持及发展种植业的最佳途径。 相似文献
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在山西省黎城县,对以核桃、花椒、君迁子为林冠的林药、林粮、林经等16种农林复合栽培模式前3年的经济效益进行了统计,并以净现值为指标进行了经济效益评价。结果表明,以花椒为林冠的复合类型投入成本较核桃和君迁子的低,且收入较其它2种的高;林药复合类型总体经济效益高于林粮和林经复合类型;林药复合类型中花椒—板蓝根复合栽培模式的经济效益最好,林粮复合类型中花椒—谷子复合栽培模式的经济效益最好,林经复合类型中核桃—辣椒复合栽培模式的经济效益最好。 相似文献
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土壤环境变化是恢复生态学研究的重要内容之一,加强混农林的立体优化配置,有利于控制水土流失、改善土壤环境质量和提高生态脆弱区的生态和经济效益。文中系统总结混农林业对石漠化地区土壤水分、养分、生物特征的影响,阐明在石漠化极端脆弱生态环境条件下,林木与农作物存在的水肥竞争以及复合农田中树龄较小时对土壤生物活性的抑制作用,进一步从石漠化地区土壤环境角度对混农林业的水分利用策略、乡土树种的选择搭配、有益土壤生物的应用等方面提出建议,以期为喀斯特石漠化地区提高土地生产力、控制水土流失、发展立体生态农业等提供参考。 相似文献
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The objective of this study was to determine crop and tree productivity in several alley cropping planting patterns. The four-
year study was conducted in western Oregon, United States and involved irrigated sweet corn (Zea mays) intercropped between
hedgerows of red alder (Alnus rubra) and black locust (Robina pseudoacacia). Three alley cropping planting patterns with variable
plant populations and tree-crop proximity were tested with each tree species in a randomized block design. Space available
to trees and crops determined yield of both plant components. High crop yield coincided with low pruning yield, and vice versa.
Compared to monocropping, yield reductions in traditional alley cropping planting patterns with widely spaced, double tree
rows ranged from 5% to 15%. A. rubra and R. pseudoacacia coppiced readily and produced 0.9 to 4.7 tons of dry matter pruning
biomass per growing season, depending on planting pattern and year. A. rubra yield continually increased during the trial,
while the ability of R. pseudoacacia to produce green manure after frequent coppicing appeared to weaken. After four years,
soil organic matter was 4 to 7% higher in the topsoil of an alley cropping system compared to a monocropping system. However,
continuous growing of sweet corn resulted in decreased soil organic matter levels in both cropping systems compared to original
levels. Crop yield reductions and the need for additional management inputs constrain the implementation of alley cropping
in temperate climates. Only if benefits other than minor soil fertility improvements are realized is alley cropping a feasible
alternative in temperate climate regions.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Smallholder perceptions of agroforestry projects in Panama 总被引：7，自引：1，他引：7
The potential effects of agroforestry systems on conservation and development have been well documented. Panama has seen a
substantial rise in the number of projects with an agroforestry component in the 1990s. There has been insufficient research
on the actual impacts of these projects on smallholders and of farmers' attitudes towards these systems. This study explores
the perceived socioeconomic and environmental impacts of five agroforestry projects in Panama. A total of 68 smallholders
were administered semi-structured interviews. In addition, 13 agroforestry experts from NGOs, government departments and research
institutes were interviewed, and their responses were compared with those of the smallholders. While the projects led to an
increase in the standard of living by providing wood products and fruit for domestic consumption, farm income levels generally
remained unchanged. This was due primarily to limited market development, the lack of marketing organizations and poor access
roads. In terms of environmental impacts, the farmers' responses suggested a slight decline in slash-and-burn agriculture,
and an increase in tree planting activities. Some environmental benefits were observed by farmers, including reduced soil
erosion, increased soil fertility, and improved quality and quantity of water sources. Nevertheless, slash-and-burn agriculture
was still the norm for the majority of farmers. Most farmers continued to harvest wood from primary and secondary growth to
meet their domestic wood requirements, rather than relying on trees planted in agroforestry projects. The main obstacles preventing
increased agroforestry adoption included insufficient agroforestry extension, inappropriate project design or management (such
as top-down management approaches, and the use of food incentives), smallholders' economic constraints, and larger policy
issues. Recommendations are proposed to improve project design and management, and to address the economic and policy constraints.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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根据生态学的边缘效应理论、天然林的自然稀疏结果、造林树种的生态学特性以及水分平衡理论确定合理的造林密度,是保证造林成效的关键。针对区域的自然条件和社会经济状况,采取相应的营林手段是发展草原林业的重要保证。按照生态经济学原理,开展农林复合经营是保护生态平衡、摆脱贫困、发展农业经济的一个重要的途径。 相似文献
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Trees of the genus Ficus, integral components of indigenous rainfed agro-ecosystems of the southern dry agro-climatic zone of Karnataka, southern India, have traditionally been associated with the ecological service of soil quality enhancement in addition to various direct use benefits. We assessed the soil enrichment service of Ficus benghalensis L. a common Ficus species in these agroforestry systems, by quantifying nutrient return via litter fall. Litterfall estimation and chemical analysis of litter showed that F. benghalensis trees produce 3,512 kg ha-1 of litter annually which, on decomposition, can satisfy up to 76.70 % of N, 20.24% of P and 67.76% of K requirements of dryland crops annually per hectare. This can lead to an avoided cost of compost of US $ 36.46 ha-1·a-1 in dryland farming systems. The slow rate of decay of Ficus litter, as revealed in litter decomposition studies indicates its potential as ideal mulch for dryland soils. We discuss the complementarity between Ficus litterfall and cropping patterns in Mandya, and its implications for rainfed agricultural systems. 相似文献
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沙地“小老树”的开发与改造是当前林业生产中亟待解决的问题。为提高出材率 ,可采用挖根采伐的方式 ,在改造中要使规划具备整体性 ,渠路一体化。渠路边单行栽植杨树。不营造片林采用大行距、密株距带状造林形成林农间作的混农林业 ,从而可提高经济效益。 相似文献