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重庆梨园穴施底肥聚表土建园技术及其效应
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作者 阮光伦 徐兴慧 徐维 《中国南方果树》 北大核心 2015年第2期93-95,共3页
介绍了重庆市涪陵区在南方早熟梨生产上采用挖穴施入土杂肥,并聚集肥沃表土形成高70cm左右土墩定植的建园技术以及取得的良好效果,并对这种建园方法产生的效应进行了分析。
关键词 南方山区 早熟梨 改土建园 聚表土 效应
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Effects of Straw Covering and Different Types of Potassium Fertilizer on Salinity Accumulation in Surface Layer of Tobacco-planted Paddy Soil 被引量:3
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作者 彭金良 雷文杰 +1 位作者 黄景崇 李迪秦 《Agricultural Science & Technology》 CAS 2013年第6期905-910,共6页
[Objective] This study aimed to investigation the effects of straw covering and different types of potassium fertilizer on salinity accumulation in surface layer of tobacco-planted paddy soil in southern China. [Metho... [Objective] This study aimed to investigation the effects of straw covering and different types of potassium fertilizer on salinity accumulation in surface layer of tobacco-planted paddy soil in southern China. [Method] Tobacco variety ‘Yunyan87’ was used as the experimental material to investigate the effects of salinity accumulation in surface layer of tobacco-planted paddy soil on the growth and development of flue-cured tobacco using different types of potassium fertilizer and mulching cultivation methods. [Result] The results showed that K+ , Ca2+ , SO42and NO3-were the major salt ions in topsoil at different growth stages of flue-cured tobacco, Na + and Mg2+ contents were also relatively high at vigorous growth stage, indicating that these salt ions were easily accumulated in surface layer of soil; to be specific, the absolute increase of salt ion concentration showed a decreasing order of K+ SO42- NO3-Ca2+ Mg2+ Na+ Cl-, while the relative increase of salt ion concentration showed a decreasing order of Ca2+ K+ Na+ NO3-SO42-Mg2+ Cl-. At 60 d posttransplanting, total salt content in topsoil reached the minimum of 359.1 mg/kg in Treatment 2, total salt content in topsoil reached the maximum of 536.1 mg/kg in Treatment 5 (CK), which was significantly higher than that in other treatments. At 90 d post-transplanting, no significant difference was observed in total salt content among various treatments. At harvesting period, total salt content in topsoil reached the maximum of 3 278.4 mg/kg in Treatment 1, which was significantly higher than that in other treatments. Topsoil pH showed no significant differences among various treatments at three different periods, ranging from 5.39 to 5.59. Straw covering could effectively reduce salt content in topsoil, accelerate vigorous growth of tobacco, shorten vigorous growth period and increase plant height, leaf number and lead area; at vigorous growth stage, root vitality and root volume of tobacco were improved, but the yield and output value were relatively low. Major agronomic traits and yield of tobacco showed no significant difference among various treatments. Output value of tobacco reached the maximum of 24 196.8 yuan/hm2 in Treatment 3, which was significantly higher than that in other treatments. [Conclusion] Appropriate types and proportions of potassium fertilizer and straw covering can effectively reduce the total salt content in tobacco-planted paddy soil and increase the effective supply amount of K+ , Ca2+ , SO42-and NO3-, thereby promoting and improving the root vitality of tobacco, which is conducive to the growth and development of tobacco and will eventually enhance the yield, quality and economic benefits of flue-cured tobacco. 展开更多
关键词 Flue-cured tobacco Tobacco-planted paddy soil Salinity accumulation in surface layer Potassium fertilizer Straw covering
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Influence of "Covercrete" Morphology on Durability Properties
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作者 Pavel Reiterman Karel Kolar +1 位作者 Michaela Dudikova Petr Konvalinka 《Journal of Civil Engineering and Architecture》 2012年第7期928-932,共5页
Many leading experts agree on the importance of monitoring the "concrete skin" as the most loaded area affected by the external environment. Surfacing, concrete mixture composition and curing are of great importance... Many leading experts agree on the importance of monitoring the "concrete skin" as the most loaded area affected by the external environment. Surfacing, concrete mixture composition and curing are of great importance for the concrete surface resistance. The paper introduces an experimental program focused on the monitoring of de-icing salts resistance, depending on surface roughness. Quantitative evaluation of the concrete surface was performed by using confocal laser scanning microscopy, which is the new generation of optical systems that are able to make all measurements in 3D resolution. These measurements are supplemented by results of mechanical and absorption tests. 展开更多
关键词 Confocal microscopy concrete surface durability.
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Mapping Soil Texture of a Plain Area Using Fuzzy-c-Means Clustering Method Based on Land Surface Diurnal Temperature Difference 被引量:7
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作者 WANG De-Cai ZHANG Gan-Lin +3 位作者 PAN Xian-Zhang ZHAO Yu-Guo ZHAO Ming-Song WANG Gai-Fen 《Pedosphere》 SCIE CAS CSCD 2012年第3期394-403,共10页
The use of landscape covariates to variability of soil properties in similar estimate soil properties is not suitable topographic and vegetation conditions. for the areas of low relief due to the high A new method wa... The use of landscape covariates to variability of soil properties in similar estimate soil properties is not suitable topographic and vegetation conditions. for the areas of low relief due to the high A new method was implemented to map regional soil texture (in terms of sand, silt and clay contents) by hypothesizing that the change in the land surface diurnal temperature difference (DTD) is related to soil texture in case of a relatively homogeneous rainfall input. To examine this hypothesis, the DTDs from moderate resolution imagine spectroradiometer (MODIS) during a selected time period, i.e., after a heavy rainfall between autumn harvest and autumn sowing, were classified using fuzzy-c-means (FCM) clustering. Six classes were generated, and for each class, the sand (〉 0.05 mm), silt (0.002-0.05 mm) and clay (〈 0.002 mm) contents at the location of maximum membership value were considered as the typical values of that class. A weighted average model was then used to digitally map soil texture. The results showed that the predicted map quite accurately reflected the regional soil variation. A validation dataset produced estimates of error for the predicted maps of sand, silt and clay contents at root mean of squared error values of 8.4%, 7.8% and 2.3%, respectively, which is satisfactory in a practical context. This study thus provided a methodology that can help improve the accuracy and efficiency of soil texture mapping in plain areas using easily available data sources. 展开更多
关键词 digital soil mapping land surface temperature low relief area MODIS remote sensing
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