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针对农牧交错带草地生态系统的特点,以P-S-R (Pressure-State-Response)模型为基础,采用熵权法和物元模型构建草地生态安全综合评判模型,对陕北农牧交错带榆林地区12县(区)草地生态安全进行实证分析。结果表明:2019年陕北农牧交错带草地生态安全等级总体上北部高于南部,神木市草地生态安全等级最优;草地生态安全保护治理措施是研究区草地生态安全等级产生差异的主要因素,建议实行分区域生态调控;熵权物元模型在陕北农牧交错带草地生态安全评价中模拟效果较好。 相似文献
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川中丘陵地玉米避灾减灾栽培技术研究 总被引:1,自引:0,他引:1
以川中丘陵的典型地三台为基点,从影响玉米产量的主导因子——干旱着手,对品种、播期、密度、肥料投入四因素进行不同生态区品种同田展示、播期试验、三元二次正交回归旋转试验、三元二次正交回归通用设计试验研究,结果经计算机分析,将玉米栽培技术组装配套。得出,根据不同种植地所处的生态区域和台位分布选择相应的品种;谷雨节前后播种,叶面积系数与单株生产力协调一致达最佳,玉米产量最高,既能抗夏旱又能避伏旱;每667平方米种植3500~4000株、施纯氮20公斤以上、施氧化钾9公斤、单产可达500公斤以上;单产600公斤的栽培方案为每667平方米种植4673株、施纯氮26.73公斤、施氧化钾9公斤。 相似文献
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北方农牧交错带界定的研究进展 总被引:1,自引:0,他引:1
作为农牧区的交汇地带,北方农牧交错带的生态环境十分敏感,是我国重要的生态屏障。本文基于前人的研究综述了农牧交错带的概念、形成、北方农牧交错带空间界定研究进展和气候变化对北方农牧交错带空间位置变化的影响。得出如下结论:前人对北方农牧交错带界定的研究多是定性化的,界定的范围只是大致的地理位置。气候因素是北方农牧交错带界定研究中的重要指标因素。建议:在定性化的基础上运用GIS等现代技术手段对北方农牧交错带进行更加深入的定量研究,从而更加准确地确定其地理位置和面积。并且考虑经济发展、政策制度、人类活动等人文因素的影响。 相似文献
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覆盖条件下不同生育期干旱胁迫对玉米植株生长的影响探讨 总被引:1,自引:0,他引:1
《绿色科技》2017,(9)
在大棚采用盆栽实验的方法对玉米进行了不同生育期干旱胁迫实验(Ⅰ:三叶-拔节期;Ⅱ:拔节-抽雄期;Ⅲ:抽雄-籽粒形成期;Ⅳ:籽粒形成-完熟期),研究了在地膜覆盖、秸秆覆盖和裸地进行干旱胁迫对玉米植株生长的影响。结果显示:在Ⅲ期时进行干旱胁迫,株高受影响最大,其次是Ⅱ期,且在地膜覆盖下出现最大值,在裸地处理下出现最小值;对叶面积的影响依次为Ⅱ期Ⅲ期Ⅰ期,且在地膜覆盖下出现最大值,在裸地处理下出现最小值;生物量在Ⅳ期出现最大值;对根冠比的影响依次为Ⅱ期Ⅲ期Ⅰ期。研究得出了玉米生长发育性状和不同覆盖条件之间有着重要的关系,故选择优良的覆盖方式对玉米种植可起到关键的作用,从上述分析得出了玉米生育状况的优异程度从高到低排列顺序为:地膜覆盖秸秆覆盖裸地。 相似文献
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玉米栽培中的种植密度是影响产量的一个关键因素,我们参照近年来玉米品种的“高产综合栽培模型研究”的试验结果,对不同类型(平展型和紧凑型)品种的适宜密度进行研究,为玉米生产提供依据. 一、试验方法试验设在本所试验田,土质为黑五花土,肥力均匀.试验采用“二次通用旋转设计”和“最优设计”,并在当地进行大面积生产示范,并进行跟踪调查,对模式加以验证和订正. 相似文献
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Erosion losses were investigated in a field experiment, from 90 × 15 m erosion plots at 4% slope in the western Himalayan
valley region of India. The plots were planted with Leucaena leucocephala and Eucalyptus hybrid, either as block plantation
or in alley farming with maize (Zea mays), Chrysopogon fulvus grass or turmeric (Curcuma longa). The treatments also included
contour planting of sole maize, sole Chrysopogon fulvus grass and a clean weeded cultivated fallow. During the nine year study
period, the average annual monsoon rainfall was about 1000 mm and it caused 347 mm runoff and 39 Mg ha-1 soil loss per year from fallow plots. The runoff and soil loss were reduced by 27% and 45% by contour cultivation of maize.
Contour tree-rows or leucaena hedges reduced the runoff and soil loss by 40% and 48%, respectively, over the maize plot, reducing
soil loss to about 12.5 Mg ha-1. This reduction in erosion was primarily due to the barrier effect of tree or hedgerows and micro-terraces formed through
sediment deposition along the contour barriers. Such vegetative measures, that are productive while being protective, offer
viable alternative for erosion control in areas with gentile slopes of the valley region. High density block plantations of
eucalyptus and leucaena almost completely controlled erosional losses and can be recommended for steeper slopes that are vulnerable
to heavy erosion.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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山地苹果产业已成为陕北山区农民增收和加快农村经济发展最具优势的区域特色产业。陕北得天独厚的自然条件优势与政府强有力的扶持,形成了山地苹果发展的良好势头。但实际发展还存在区域劣势明显、农民种植积极性不高、技术支撑不力、规模化经营水平较低等问题。如何有针对性地解决问题,使苹果产业健康发展已成为各级政府面临的现实问题。志丹县九月红果业农民合作社的订单农业、依托科技搞标准化种植、为果农担保贷款的操作模式,是一个更高层次、更有效的社会经济组织方式,值得推广借鉴。建议在山地苹果产业发展中采取措施,制定发展规划、鼓励农民发展果业、强化跟踪指导服务、构建农民专业合作社金融支持体系。 相似文献
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R. A. Nelson P. G. Grist K. M. Menz R. A. Cramb E. P. Paningbatan M. A. Mamicpic 《Agroforestry Systems》1996,35(2):203-220
Soil erosion in the Philippine uplands is severe. Hedgerow intercropping is widely advocated as an effective means of controlling soil erosion from annual cropping systems in the uplands. However, few farmers adopt hedgerow intercropping even in areas where it has been vigorously promoted. This may be because farmers find hedgerow intercropping to be uneconomic compared to traditional methods of farming. This paper reports a cost-benefit analysis comparing the economic returns from traditional maize farming with those from hedgerow intercropping in an upland community with no past adoption of hedgerows. A simple erosion/productivity model, Soil Changes Under Agroforestry (SCUAF), is used to predict maize yields over 25 years. Economic data were collected through key informant surveys with experienced maize farmers in an upland community. Traditional methods of open-field farming of maize are economically attractive to farmers in the Philippine uplands. In the short term, establishment costs are a major disincentive to the adoption of hedgerow intercropping. In the long term, higher economic returns from hedgerow intercropping compared to open-field farming are realised, but these lie beyond farmers limited planning horizons. 相似文献
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由于耕地少和石漠化、沙漠化以及过度开发自然环境,造成生态环境破坏,严重制约着农村经济的发展。生态移民工程将农民迁入到其他地区,通过发展乡村旅游、生态旅游改善农民生活环境,带动农民就业。生态修复生态脆弱地区,改善农村石漠化、荒漠化、水土流失等,有利于农村经济、人口、资源、环境的可持续发展,对新农村建设有着重要的意义。 相似文献
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内蒙古河套灌区盐碱地枸杞种植效益分析 总被引:3,自引:0,他引:3
枸杞不仅是盐碱地利用的重要经济树种,而且也是重要的生态树种。它具有较强的改土和保持水土作用、以及较高的经济效益和良好的社会效益。通过分析河套灌区盐碱地枸杞的种植效益,结果表明:种植枸杞3年,0~40cm土壤由表层向下分别脱盐77.97%、69.19%、44.98%,且Cl-、SO42-、Na++K+下降较为明显;枸杞是河套平原传统农业支柱产业之一,每公顷的纯收益约在35 898.7~43 110.7元之间;同时,它在引导农村产业结构调整,促进农村经济的发展等方面具有重要作用。 相似文献
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采用径流小区实验的方法,在李子口小流域设立了6个不同植被类型的径流小区,研究径流小区不同植被条件下降雨对土壤侵蚀的影响,结果如下:(1)不同植被条件下,降雨对土壤侵蚀的影响可表现为撂荒地小区>农耕地小区>林地小区,降雨对林地的土壤侵蚀弱,林地对当地水土的保持能力强,最适合作为当地水土保持的植物措施。(2)总体上,6个径流小区的降雨量、降雨侵蚀力与地表径流量、径流深、土壤流失量之间的相关性均表现为显著正相关的关系,表明降雨对当地土壤侵蚀作用强,需重点防护。研究揭示了研究区降雨与土壤侵蚀的相关性,比较了不同植被条件下降雨对土壤侵蚀的影响,为水土保持的相关研究提供参考与借鉴。 相似文献
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Charles Yamoah 《Agroforestry Systems》1991,13(1):87-94
In the northern Rwandan Highlands, farming is intensive due to unavailability of land. A study was conducted to choose suitable intercrops with Sesbania for alley cropping prior to cutback of the shrub, a practice that would enable farmers to continuously crop their fields. Potato, pole bean, dwarf bean and maize were tested in 4-m alleys. The study concludes that pole bean is most appropriate while maize is the least preferred intercrop for a 6-month-old Sesbania. Yield losses of intercrops were attributed principally to shading by Sesbania hedges, but competition for nutrients and soil space as well as disease incidence are also possible. 相似文献
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生态环境的恶化已经成为当前国际社会最为关心和最迫切需要解决的问题。本文详细地阐述了森林与水土流失、土壤沙漠化、土壤退化、大气污染和酸沉降、噪声污染之间的关系,并认为应该发展森林来改善人类的生存环境。 相似文献