Soil penetration resistance

  • 文章类型: Journal Article
    洪水对生命和货物损失有重要影响。城市绿地对于减轻洪水影响至关重要。然而,他们预防洪水的能力取决于他们的状况,特别是在草坪等受人类活动影响严重的地区。这里,我们开发了一种简单的方法来评估洪水调节,以土壤渗透阻力为代表,并在冬季在维尔纽斯(立陶宛)的城市草坪上进行了测试。我们使用应用程序开发了一个实验设计,用于收集数据并在GIS环境中工作。为了了解它们的空间关系,地统计学(例如,应用了半变异函数模型和普通克里格映射)和空间统计((Moran的全球自相关指数以及聚类和离群值分析(AnselinLocalMoran'sI))工具。测试方法的初步结果表明,由于管理实践,所研究的草坪具有不同的防洪能力。然而,由于洪水调节(土壤渗透阻力)可以全年变化,因此必须在不同的土壤水分条件下应用。•开发了一种新颖的方法来使用土壤渗透阻力作为替代来估计洪水调节;•使用城市草坪来测试该方法并识别具有低和高洪水调节能力的区域;•该方法快速评估不同环境中的草坪洪水滞留能力。
    Floods have an important impact on life and loss of goods. Urban green spaces are crucial to mitigating flood impact. However, their capacity to prevent floods depends on their condition, especially in areas highly affected by human activities such as lawns. Here, we developed a simple method to assess flood regulation using soil penetration resistance as a proxy and tested it on an urban lawn in Vilnius (Lithuania) in winter. We developed an experimental design using an app for collecting data and working with it in a GIS environment. To understand their spatial relations, geostatistical (e.g., semi-variogram model and ordinary kriging mapping) and spatial statistics ((Moran\'s global autocorrelation index and Cluster and Outlier Analysis (Anselin Local Moran\'s I)) tools were applied. The preliminary results from the tested method showed that the lawn studied has different capacities to retain floods due to the management practices. Nevertheless, it is essential to be applied in different soil moisture conditions since flood regulation (soil penetration resistance) can be variable throughout the year.•A novel method was developed to estimate flood regulation using soil penetration resistance as a proxy;•An urban lawn was used to test the method and identify areas with low and high capacity for flood regulation;•The method quickly assesses lawn flood retention capacity in different environments.
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  • 文章类型: Journal Article
    土壤特性的恢复和自然树木再生的适当生长是选择性伐木作业后保持森林生产力的关键要素。这项研究是针对伊朗北部山毛榉混交林的滑道上的Alder木和枫木两种先锋幼苗的土壤特性和自然生长进行的。为了检查长期影响,我们随机选择了六条滑道,自上次使用(10、20和30年前)以来的三个时间段中的每一个都建立了两个重复。大小为4m×10m的随机地块,每个滑道上有三个地块,没有土壤压实的区域上有六个地块(对照),被选中。测量包括土壤的物理和化学性质以及生长,以及幼苗的建筑和质量特征。结果表明,10和20年生滑道的所有土壤特性均与控制区存在显着差异(20年生滑道中的土壤水分除外)。30年的滑道显示其他土壤特性的值与控制区没有显着差异,除了有机质和土壤氮的含量,比对照组少。滑道对所有的生长都有负面影响,定性,和幼苗的建筑指数。幼苗的特性与土壤特性有关,并且与土壤渗透抗性的相关性最高(茎生长的R值从-0.41到-0.63,p<0.05;根生长为-0.57至-0.90,p<0.01;生物量为-0.76至-0.86,p<0.01)。Alder木和枫木幼苗的土壤渗透阻力与Dickson质量指标之间的相关系数为,分别,-0.74和-0.72,p<0.01。土壤紧实度对根系生长的负面影响(al木幼苗为-27.69%,枫树幼苗为-28.08%)大于对茎生长的负面影响(al木幼苗为-24.11%,枫树幼苗为-16.27%)。量的增长,定性,and木幼苗的建筑指数高于枫木幼苗。尽管与最初一年的枫树幼苗相比,al木是更好的选择,我们的研究结果表明,建议在伐木作业后在滑道上种植al木和枫木。
    The recovery of soil properties and the proper growth of natural tree regeneration are key elements for maintaining forest productivity after selective logging operations. This study was conducted on the soil properties and natural growth of two pioneer seedling species of alder and maple which were on skid trails in the mixed beech forests of northern Iran. To examine the long-term effects, we randomly selected six skid trails, with two replicates established for each of three time periods since last use (10, 20, and 30 years ago). Random plots 4 m × 10 m in size, three plots on each skid trail and six plots on areas without soil compaction (control), were selected. Measurements included the physical and chemical properties of the soil and the growth, and the architectural and qualitative characteristics of the seedlings. The results showed that all the soil properties of the 10- and 20-year-old skid trails were significantly different from the control area (except for the soil moisture in the 20-year-old skid trail). The 30-year-old skid trail showed values of other soil properties which were not significantly different from the control area, except for the amounts of organic matter and soil nitrogen, which was less than the control. The skid trails had a negative effect on all of the growth, qualitative, and architectural indices of seedlings. The characteristics of seedlings were related to soil characteristics and had the highest correlation with the soil penetration resistance (R-value from -0.41 to -0.63 for stem growth, p < 0.05; -0.57 to -0.90 for root growth, p < 0.01; and -0.76 to -0.86 for biomass, p < 0.01). The correlation coefficient between soil penetration resistance and the Dickson quality index of alder and maple seedlings was, respectively, -0.74 and -0.72, p < 0.01. The negative effect of soil compaction on root growth (-27.69% for alder seedlings and -28.08% for maple seedlings) was greater than on stem growth (-24.11% for alder seedlings and -16.27% for maple seedlings). The amount of growth, qualitative, and architectural indices of alder seedlings were higher than that of maple seedlings. Although alder is a better choice as compared to maple seedling in the initial year, the results of our study show that it is recommended to plant both alder and maple on skid trails after logging operations.
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  • 文章类型: Journal Article
    水稻休耕黑克是在零耕作条件下在重质地蒙脱石粘土土壤中作为中继作物在残留水分情况下生长的。由于作物是在季风后季节种植的,由于有限的水供应和没有降雨,作物经常经历最终压力。蒙脱石粘土土壤中的地面灌溉对豆类作物具有抑制作用,因为淹没会导致枯萎。因此,零耕种水稻休耕黑克必须在开花期(播种后35天)补充微灌,以减轻水分胁迫并提高生产率。因此,在一个公顷田地的一角创建了微型农场池塘,以在季风季节收获雨水,并在开花期通过移动式洒水器对保护性农业下种植的作物进行救生灌溉。土壤开裂也是蒙脱石黏土的常见现象,其中蒸发损失将更多地通过裂缝表面。因此,本研究旨在研究土壤物理性质的变化,与机械化播种和收获以及补充移动喷灌相结合的作物建立和生产力。在手工收获水稻前10天通过广播播种黑克,在水稻机收后手动绘制单行播种机,并在水稻机收前4天通过广播播种,分别进行了试验,并与救生灌溉相结合。结果表明,车轮通过次数和救生灌溉对土壤渗透阻力和土壤水分有很大影响。联合收割机,然后不播种,增加了所有层的土壤渗透阻力(0-5厘米,5-10厘米和10-15厘米)。两次通过车轮将平均土壤渗透阻力从407KPa增加到502KPa。收获时的土壤渗透阻力(0-5厘米)表明,在30DAS上补充生命灌溉的稻田人工收获前10天,通过人工广播播种的黑克将土壤渗透阻力从690Kpa降低到500Kpa,在0-5厘米时,分别为740Kpa至600Kpa和760Kpa至620Kpa,5-10厘米和10-15厘米层。总的来说,与5-10cm和10-15cm至30DAS(开花阶段)的其他层相比,0-5cm的表面层的水分消耗速率很快。水分含量与土壤渗透阻力呈反比关系。土壤渗透阻力也与根长成反比,其中根长随着土壤渗透阻力的增加而降低。在60DAS下测得的土壤裂缝更深,没有播种(宽度为3.94cm,深度为13.67cm),这主要是由于表层压实。相对含水量,通过在30DAS上进行的补充灌溉,无论作物建立方法如何,比叶重和叶绿素含量都显着提高。结果进一步表明,由于联合收割机和无耕种播种机,潮湿土壤中耕层的压实对产量(457kgha-1)有负面影响,由于补充灌溉增加了土壤水分,这一比例提高了19.03%。由于通过移动喷头进行补充救生灌溉,不同处理的平均产量增加了20.4%。
    Rice fallow black gram is grown under the residual moisture situation as a relay crop in heavy texture montmorillonite clay soil under zero till condition. Since the crop is raised during post monsoon season, the crop often experiences terminal stress due to limited water availability and no rainfall. Surface irrigation in montmorillonite clay soil is determent to pulse crop as inundation causes wilting. Therefore, zero tilled rice fallow black gram has to be supplemented with micro irrigation at flowering stage (35 days after sowing) to alleviate moisture stress and to increase the productivity as well. Hence micro farm pond in a corner of one ha field was created to harvest the rain water during monsoon season and the same was utilized to supplement the crop with lifesaving irrigation through mobile sprinkler at flowering stage for the crop grown under conservation agriculture. Soil cracking is also the common phenomena of montmorillonite clay soil where evaporations losses would be more through crack surfaces. The present study was therefore conducted to study the changes in the soil physical properties, crop establishment and productivity in conjunction with mechanized sowing and harvest and supplemental mobile sprinkler irrigation. Sowing of black gram by broadcasting 10 days prior to the manual harvest of rice, manual drawn single row seed drill after the machine harvest of rice and sowing by broadcasting at 4 days prior to machine harvest of rice was experimented separately and in combination with lifesaving irrigation. Results indicated that the number of wheel passes and lifesaving irrigation had a very strong impact on soil penetration resistance and soil moisture. Combined harvester followed by no till seed drill increased the soil penetration resistance in all the layers (0-5 cm, 5-10 cm and 10-15 cm). Two passes of wheel increased the mean soil penetration resistance from 407 KPa to 502 KPa. The soil penetration resistance (0-5 cm) at harvest shown that black gram sown by manual broadcasting 10 days prior to manual harvest of paddy supplemented with life irrigation on 30 DAS reduced the soil penetration resistance from 690 Kpa to 500 Kpa, 740 Kpa to 600 Kpa and 760 Kpa to 620 Kpa respectively at 0-5 cm, 5-10 cm and 10-15 cm layer. In general, moisture depletion rate was rapid in the surface layer of 0-5 cm as compared to other layers of 5-10 cm and 10-15 cm up to 30 DAS (Flowering stage). The moisture content and the soil penetration resistance had an inverse relationship. The soil penetration resistance also had an inverse relationship with the root length in which the root length lowers as the soil penetration resistance increases. The soil crack measured at 60 DAS was deeper with no till seed drill (width of 3.94 cm and depth of 13.67 cm) which was mainly due to surface layer compaction. The relative water content, specific leaf weight and chlorophyll content were significantly improved through the supplemental irrigation given on 30 DAS irrespective of crop establishment methods. The results further indicated that compaction of ploughed layer in the moist soil due to combined harvester and no till seed drill had a negative impact on yield (457 kg ha-1), which was improved by 19.03 per cent due to increased soil moisture with supplemental irrigation. The mean yield increase across different treatments due to supplemental lifesaving irrigation through mobile sprinkler was 20.4 per cent.
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  • 文章类型: Journal Article
    土壤种子库在植被动态中起着核心作用,可能是生态恢复的重要来源。然而,绝大多数种子库研究只检查了最上面的土壤层(0-10厘米);因此,我们对种子库的深度分布和深埋种子的生态意义的认识是有限的。我们研究的目的是检查土壤种子库的精细尺度垂直分布到80厘米的深度,这是迄今为止研究的最大深度梯度之一。我们的模型系统是东匈牙利的碱性草原,以恶劣的环境条件为特征,由于具有Vertic地平线的Solonetz土壤参考组。我们提出了以下问题:(1)土壤种子库的幼苗密度和物种丰富度如何沿垂直梯度变化以及可以检测到发芽种子的深度?(2)发芽种子的深度分布与物种性状之间有什么关系?
    在五个研究地点中,用螺旋钻收集四个80厘米深的土壤核心(4厘米直径)用于土壤种子库分析。按深度将每个样品分成16个5cm的片段(总共320个片段)。通过在筛上洗涤来浓缩样品,然后在未加热的温室中发芽。在每个岩心位置(0-80厘米深度,1厘米分辨率)。我们测试了在土壤部分(N=320)中观察到的幼苗的数量和物种丰富度,使用负二项广义线性回归模型,其中采样层和穿透阻力是预测变量。我们运行了形态学组的模型(语法类/forbs),生态组(草地物种/杂草)和生命形式类别(短命/多年生)。我们还测试了种子形状指数,种子质量,物种的需水量或耐盐性会影响其种子库的垂直分布。
    种子库的发芽种子密度和物种丰富度随着土壤深度和穿透阻力的增加而降低。然而,即使在最深的土壤层中,我们也检测到了6种9种可发芽的种子。Forbs,草原物种和短命物种大量出现在深层,从零开始,杂草和多年生物种失踪。与细长的种子相比,圆形种子在较深的土壤层中更丰富,但种子质量和生态指标值对种子库的垂直分布没有影响。我们的研究提请注意深埋种子的潜在生态重要性,这些种子可能是严重干扰后恢复的来源。由于Vertisols覆盖全球3.35亿公顷,这些发现可能与全球许多地区和生态系统有关。我们强调需要在其他土壤和栖息地类型中进行类似的研究,以测试深埋种子的存在是否特定于具有Vertic特征的土壤。
    Soil seed banks play a central role in vegetation dynamics and may be an important source of ecological restoration. However, the vast majority of seed bank studies examined only the uppermost soil layers (0-10 cm); hence, our knowledge on the depth distribution of seed bank and the ecological significance of deeply buried seeds is limited. The aim of our study was to examine the fine-scale vertical distribution of soil seed bank to a depth of 80 cm, which is one of the largest studied depth gradients so far. Our model systems were alkaline grasslands in East-Hungary, characterised by harsh environmental conditions, due to Solonetz soil reference group with Vertic horizon. We asked the following questions: (1) How do the seedling density and species richness of soil seed bank change along a vertical gradient and to what depth can germinable seeds be detected? (2) What is the relationship between the depth distribution of the germinable seeds and the species traits?
    In each of the five study sites, four soil cores (4 cm diameter) of 80 cm depth were collected with an auger for soil seed bank analysis. Each sample was divided into sixteen 5-cm segments by depth (320 segments in total). Samples were concentrated by washing over sieves and then germinated in an unheated greenhouse. Soil penetration resistance was measured in situ next to each core location (0-80 cm depth, 1-cm resolution). We tested the number and species richness of seedlings observed in the soil segments (N = 320), using negative binomial generalized linear regression models, in which sampling layer and penetration resistance were the predictor variables. We ran the models for morphological groups (graminoids/forbs), ecological groups (grassland species/weeds) and life-form categories (short-lived/perennial). We also tested whether seed shape index, seed mass, water requirement or salt tolerance of the species influence the vertical distribution of their seed bank.
    Germinable seed density and species richness in the seed bank decreased with increasing soil depth and penetration resistance. However, we detected nine germinable seeds of six species even in the deepest soil layer. Forbs, grassland species and short-lived species occurred in large abundance in deep layers, from where graminoids, weeds and perennial species were missing. Round-shaped seeds were more abundant in deeper soil layers compared to elongated ones, but seed mass and ecological indicator values did not influence the vertical seed bank distribution. Our research draws attention to the potential ecological importance of the deeply buried seeds that may be a source of recovery after severe disturbance. As Vertisols cover 335 million hectares worldwide, these findings can be relevant for many regions and ecosystems globally. We highlight the need for similar studies in other soil and habitat types to test whether the presence of deep buried seeds is specific to soils with Vertic characteristics.
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