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1.
新垦沙地地膜花生栽培技术研究 总被引：1，自引：1，他引：1
在新垦沙地采用了地膜花生栽培技术，并辅以“集中施肥技术”，收获了３８８．４ｋｇ／亩荚果，比一般栽培增产１２０．８％。表明地膜花生具有明显的增温、保墒，充分接受光能及抑制田间杂草等良好作用。 相似文献
2.
目前灵芝等食药用菌大多采用阔叶树栽培,对林木消耗极大,以草代木成为了现今的栽培趋势,不仅解决了原料来源的问题,而且可有效地保护森林生态环境。实验菌株选自实验室杂交菌株中的7株和亲本2株,通过统计菌丝生长速度、子实体大小、产量等农艺性状,并运用分光光度法及高效液相色谱法分析成熟子实体有效成分的含量,筛选出适合菌草栽培的菌种。实验结果表明,菌株J-1/AL-12的产量最高,同时有效成分含量也相对较高。分析不同杂交菌株间及菌草灵芝与木屑灵芝间的灵芝三萜指纹图谱,发现不同菌株的三萜含量有差异,而不同原材料栽培的灵芝子实体其三萜指纹图谱无明显差异。 相似文献
3.
草莓在粗质风沙化土地上栽培时, 如何保证草莓所需水分、养分的供给是一个重要且难解决的问题。经过试验研究, 采用保水间层栽培能解决这一关键问题。在栽植区土壤中铺设保水间层或覆盖地膜均能提高植株成活率, 提早1周左右产果, 大幅度增加产量, 取得明显经济效益。在草莓栽植区30cm深处铺设高20cm的保水间层, 可增产134.4kg/亩, 获得201.6元净经济收入。保水间层与覆盖地膜结合使用, 则净增产291.6kg/亩(130.7%), 获638.4元纯收入, 相当于当地农民人均年收入.增产原因是土填含水量(生长期内)始终保持在最适宜草莓需要的范围内, 且可防止养分淋溶损失。 相似文献
4.
根据小麦、西瓜、花生、玉米的不同生育特性,合理选用不同熟期的品种,安排空间和生育期调控,提出了小麦西瓜花生玉米四熟的间套复种栽培模式,并对模式的基本原理、主要栽培技术和经济效益加以分析和总结。 相似文献
5.
为明确垄沟覆盖集雨模式对玉米根际土壤微生物群落结构及多样性的影响,选取“登义”2号为试验材料,采用单因素完全随机试验设计,以常规平栽不覆盖为对照（CK）,依次设置垄覆普通黑色地膜沟不覆盖（HL）、垄覆液态地膜沟不覆盖（YL）、垄不覆盖沟覆秸秆（NJ）、垄覆液态地膜沟覆秸秆（YJ）、垄覆普通黑色地膜沟覆秸秆（HJ）共计6个处理,利用Illumina高通量测序技术分析土壤微生物群落构成及多样性。结果表明：（1）垄覆膜沟覆秸秆的集雨模式均有利于玉米增产、提高水分利用效率,其中HJ处理的穗行数、千粒重、产量及水分利用效率均最大,分别较对照CK提高11.22%、31.31%、88.02%、79.83%,且与CK间差异均显著（P<0.05）,而垄无覆盖沟覆秸秆的NJ处理的产量及水分利用效率均较CK低。（2）垄覆地膜各处理均能显著提高微生物群落多样性,且能改变微生物结构,但垄无覆盖沟覆秸秆的NJ处理却不能。（3）各处理的微生物群落组成在门、纲水平上均受到覆盖集雨模式的影响。土壤微生物群落中主要优势菌门为变形菌门（Proteobacteria）、酸杆菌门（Acidobacteria）、芽单胞菌门... 相似文献
6.
黄淮海平原风沙化土地果树栽培技术研究 总被引：2，自引：1，他引：2
为治理、开发黄淮海平原风沙化土地，３年间，从国内外引入１４９个果树品种，建果园１５．３ｈｍ２。历时７年，选择出良种２８个，有苗百万株，推广、辐射面积０．６６ｈｍ２。研究表明：在现有条件下，本区采用引进选择、试验示范、推广辐射的办法，进行大穴栽植，截断淤积层，矮化密植，四季修剪，植物生长剂调控树体，少量、多次、浅施肥料，增施有机肥，间作留茬，冬春少耕、免耕，早防病虫害等一整套果树栽培、管理技术，是发展黄淮海风沙化地区果林业的一条快速、可靠、有效的方法。 相似文献
7.
固沙林的经营基础与技术对策 总被引：28，自引：1，他引：28
在分析固沙林经营目的的基础上，提出了该林种的防护成熟定义，用郁闭度（覆盖度）达到π４为成熟的主要特征，通过冠幅与胸径、胸径与年龄的关系确定防护成熟龄；此外以初始成熟龄和更新龄为时间界限将林分分成３个经营时期：郁闭前期、防护成熟期和更新期，并提出了各个时期相应的经营对策。 相似文献
8.
豆芽棚滑坡体长５００ｍ，宽１５０ｍ，平均厚１０─１５ｍ，体积１００万ｍ￣３．主滑方向３０°。滑坡前缘海拔１５０ｍ，后缘海拔２００ｍ，本滑坡是在斜坡遭人为破坏（加载）后由降雨诱发的。滑坡防治措施主要拟采取减载和布设抗滑桩。 相似文献
9.
半荒风沙区土地沙漠化生物整治技术的研究 总被引：4，自引：0，他引：4
试验证明，土地沙漠化生物整治技术能在半荒漠风沙区取得显著的作用和效果。在柠条、毛条、花棒、杨柴、沙木蓼等灌木对种的适生立地上营造防风固沙林，林后３－４年，灌木就可郁闭 成林，流动 沙丘完全被控制变为固定沙丘；如能合理开发其饲料等用途，还具十分可观的经济效益。 相似文献
10.
20世纪80年代，寿光市农民利用土温室、小拱棚以及地膜覆盖等方式采取日光提升温度，从而使得蔬菜提前上市，达到增产增收的目的。从此，冬暖式蔬菜大棚种植技术迅速推广，使蔬菜深冬生产成为现实，推动了一场遍及全国的“绿色革命”。寿光发展成为“中国蔬菜之乡”，并被人们称为“中国第一号菜篮子”。 相似文献
11.
In the last several decades, the underlying surface conditions on the Qinghai-Tibet Plateau have changed dramatically, causing permafrost degradation due to climate change and human activities. This change severely influenced the cold regions environment and engineering infrastructure built above permafrost. Permafrost is a product of the interaction between the atmosphere and the ground. The formation and change of permafrost are determined by the energy exchange between earth and atmosphere system. Fieldwork was performed in order to learn how land surface change influenced the thermal regime in permafrost regions. In this article, the field data observed in the Fenghuo Mountain regions was used to analyze the thermal conditions under different underlying surfaces on the Qinghai-Tibet Plateau. Results show that underlying surface change may alter the primary energy balance and the thermal conditions of permafrost. The thermal flux in the permafrost regions is also changed, resulting in rising upper soil temperature and thickening active layer. Vegetation could prevent solar radiation from entering the ground, cooling the ground in the warm season. Also, vegetation has heat insulation and heat preservation functions related to the ground surface and may keep the permafrost stable. Plots covered with black plastic film have higher temperatures compared with plots covered by natural vegetation. The reason is that black plastic film has a low albedo, which could increase the absorbed solar radiation, and also decrease evapotranspiration. The ＂greenhouse effect＂ of transparent plastic film might effectively reduce the emission of long-wave radiation from the surface, decreasing heat loss from the earth＇s surface, and prominently increasing ground surface temperature. 相似文献
12.
中国天山西部季节性森林积雪雪层温度时空分布特征 总被引：3，自引：0，他引：3
利用2009年12月27日～2010年4月2日天山积雪站站区内开阔地和雪岭云杉(Picea schrenkiana)林下6次降雪过程后雪层内时间间隔10 min的温度数据,探讨雪层温度变化特征。结果表明,越接近地表雪层温度越高,且在雪层表面形成冷中心和(局部)暖中心;在积雪稳定期林下雪层温度高于开阔地,融雪期林下低于开阔地;林下雪层冷、暖中心出现时间晚于开阔地,其强度也小于开阔地。林下雪层温度振幅小于开阔地,林下温度振幅拐点以上雪层温度振幅随深度和时间的递减率小于开阔地,拐点以下无明显差异。初冬,林下和开阔地雪层均为较小的正温度梯度,随着气温急剧下降,温度梯度逐渐增大,且从雪表向雪底递减,林下雪层负温度梯度出现时间晚于开阔地。开阔地和林下积雪表层正温度梯度最大值分别达到0.95℃/cm和0.82℃/cm,负温度梯度大值分别达到-0.84℃/cm和-0.35℃/cm;但开阔地全雪层日平均温度梯度小于林下雪层。 相似文献
13.
14.
随着我国地膜使用面积的增加和人们对土壤微塑料污染问题的日益关注,大尺度的地膜遥感识别已成为农业生产管理、土壤污染防治的必要手段。针对地膜光谱反射特征的复杂性以及基于单一遥感影像光谱特征识别方法错分率高等问题,该文以河北省邯郸市邱县为试验区,利用GF-1数据的空间细节与Sentinel-2数据的光谱信息进行NN Diffuse Pan Sharpening融合,据此建立地膜识别的特征矩阵(NDVI、MNDWI、NDBI、IBI、PSI),基于该特征矩阵可实现自动阈值地膜分层分类识别。多种方法的地膜识别结果精度对比表明:多源光学遥感数据融合方法的总体精度为94.87%,Kappa系数达0.89,显著优于基于单一数据源的深度学习法的精度(93.14%)以及基于传统机器学习分类方法的支持向量机(85.91%)和随机森林分类法(86.78%)的精度;通过与Sentinel-2多光谱影像融合,弥补了GF-1数据光谱分辨率低的缺陷,实现了多源数据在地膜识别中的优势互补,可为相关部门农业规划与管理以及生态环境保护等研究提供大尺度、高精度的地膜分布参考数据。 相似文献
15.
Joel M. Crichlow 《Geophysical Journal International》1982,70(3):563-575
Summary. Two-dimensional finite element modelling of underground structural anomalies at shallow depths has been done to obtain the response at the ground surface to damped, vertically incident, SH -waves. Power spectral ratios are examined to determine what effects the position, shape, depth and size of the anomaly have on the surface seismograms. Based on the results gathered from a number of models, inferences are made with respect to the inverse problem: given the seismic motion of the ground surface, what can be said about the underground structure? 相似文献
16.
This paper reports on some individual constructions of ageing and how these relate to the mutual sustainability of lives and communities in the changing rurality of New Zealand in the 1990s. The Arena Society model is used to organise a discussion of the impact of technology on settlement systems, with reference to changes in the provision of banking services and their impact on the elderly. The views of older people living in the village of Tirau in the Waikato are used to ground the analysis in human experience. The concluding discussion focuses on the potential contribution of older rural residents to the ‘multiple agency’ that communities will need for survival in the ‘open society’. 相似文献
17.
DANIEL D. ARREOLA 《Geographical review》2010,100(3):291-294
Editors' note: This essay by Dan Arreola begins the second set of retrospective pieces commissioned to celebrate the centennial volume. Members of the Editorial Board responded to our request to prepare brief commentaries on landmark Geographical Review articles that were influential in their professional careers. Although many other articles touched the minds of emerging scholars, this small sampling covers a fairly wide swath of the fabric of American geography. It also reminds us that each future article has the potential to have a similar enduring value and help open new intellectual vistas. In addition to Arrreola's piece, the short essays include the musings of Barry Keim, Susan Walcott, Larry Ford, and Risa Palm. 相似文献
18.
Five short pollen diagrams of soils from Jan Mayen, Norway: a testimony of a dynamic landscape 总被引：1，自引：0，他引：1
W. O. VAN DER KNAAP 《Polar research》1987,5(2):193-206
Five soil cores varying in length from 30 to 42 cm and seven surface samples were analysed for pollen and spores. The soil layers of four cores were probably formed through redeposition of other eroded soils. Only in the Batvika core is the organic fraction of probable local origin, and here a chronology could be established. A total long-distance pollen influx of 14-22.5 grains/cm2 /year was calculated. Nearly 2, 000 long-distance pollen grains were counted; the ratios of the dominant pollen types were calculated. Around Batvika the past environment was relatively stable; only one major shift in sedimentation environment is apparent from the diagram. In another diagram, expansion of Taraxacum species could be correlated with anthropogenic soil disturbance. The former presence of Lycopodium alpinum and Selaginella selaginoides on Jan Mayen is indicated by frequent spore finds; the latter species has not been found on the island before. Two unknown spore types are discussed. 相似文献
19.
The semiarid southwestern United States is an area of rapid population growth. Urban development is encroaching upon many ecosystems, including riparian areas. Because most stream miles in the southwestern United States occur along ephemeral streams, recognizing how these ecosystems are affected by increasing urban land covers is imperative. In this study, we recorded air temperature at 30 cm above the ground surface within riparian ecosystems along nine ephemeral stream reaches in three levels of housing density: High Density (HD: >13 houses/hectare); Moderate Density (MD: 4–8 houses/hectare); Low Density (LD: <1 house/hectare) for two years in a rapidly growing city in southern Arizona. Annual and seasonal average diurnal 30-min air temperatures for each treatment show that HD air temperatures were consistently higher than LD and MD temperatures (∼0.5–1.5 °C) during the late-evening/early-morning and midday hours. Winter temperatures had the largest differences between HD and LD sites, as much as 1.4 °C. Because physiological activity in these riparian ecosystems is largely temperature-dependent, temperature shifts associated with increased housing density could result in major ecosystem changes in these semiarid areas. 相似文献
20.
Summary. Large, well-characterized single-crystals of titanomagnetite of approximate composition Fe2.4 Ti0.6 O4 were ground into spheres and orientated along specific crystallographic axes. The field dependences of the thermoremanent magnetization (TRM) and the temperature dependences of the magnetic hysteresis properties were measured and evaluated against the available theoretical models. The models, of necessity simplifications of real materials, were unable to account for many features of the experimental curves. The discrepancies were partly resolved by consideration of the mode of blocking of each individual coercivity fraction. It was deduced that the domain-walls were pinned by both dislocation lines and by inclusions or voids. A fraction of the walls were not thermally blocked. They could however be thought of as being blocked isothermally as the applied field was relaxed. The proportion of remanence blocked in by each process was found to be dependent on the strength of the inducing field through the field dependence of the blocking temperatures. A simplified model, taking these effects into account, was developed. This predicts the main features of the TRM acquisition curve and of the alternating field and thermal demagnetization spectra. 相似文献