The research on the physical function of pore system formed by roots of the soil

本研究正是针对上述研究中尚未解决的问题，对根系形成的孔隙系统的耐久性进行了研究。德永的“土壤孔隙的X射线立体照相法”阐明了源自植物根部的“由根形成的孔隙系统”作为土壤粗孔隙是优越的。在常规研究中，德永阐明了在中国黄土中十和田火山灰土壤中靛蓝植物稻垫的耐久性为32000年的16000年。然后，本研究成功地在岩手火山灰土壤中寻找了72万年前的沉积截面。样品将相连的土壤取样沿深度方向进行，并对连续性、耐久性、植物蛋白石作为根系形成的孔隙系统的相化石进行了检验。Nishine地区（在松树，沼泽神社和Egarinai 3层13年72年：）和岩手川口地区的研究方法，土壤剖面位于已知的山。岩手山北部它比（12层和 关于我们 72000年前：以岩手川口（4层）和球山麻的火山灰土（7层，寺林（1层））为对象。土壤取样在年龄上独立于表层进行了下层划分，表层是深层，存在较老的土层。通过X线和固体造影剂（CH_2I_2）对4.2cm立方体样品进行孔隙成像。根系形成的孔隙系统的耐久性表现在孔隙退化等级（0：坚固1：纤细2：内部-3：严重4：消失）上。结果概要如下所示。各试验区土壤质地的物理条件分布为粗桑迪壤土中轻粘土，干密度高，导水率小，为火山灰样的微细土。X射线立体摄影所需的孔隙图像是由Nishine地区的根形成的孔隙系统从坚固性轻微的分布。岩手川口的表层土壤是良好的，当显示出由根形成的清晰的孔隙系统时，并且当它显示在退化类中时。多马山土壤下层分区的土壤中，砷的降解程度从轻微的轻微到接近消失的程度。根形成的孔隙系统在寺林土下层分区中表现不多。根系所形成的孔隙系统的连续性在1 m左右的单元内存在波动，超过1 m土层的波动较小。而且，作为相化石的有效性在于鉴定植物根系上形成的孔隙系统的类型。尽管根系形成的孔隙系统在早更新世72万年前的土层中具有连续性，但当上述情况得到总结，且孔隙图像在部分下层渗透性消失时，整个土层仍具有耐久性，并具有相化石的意义。少

This study does the investigation of the durability of pore system formed by roots in which the above-mentioned research is unsolved with the purpose. "X-ray stereography of soil pore" which TOKUNAGAs created clarified that "pore system formed by roots" which derives from the plant root excels as soil coarse pore. In the conventional research, TOKUNAGAs clarified the durability 32000 in the Towada volcanic ash soil in the loess in China indigo plant rice pad in 16000. Then, this study succeeded for the search in respect of sedimentation cross section which was old 720000 ago in Iwate volcanic ash soil. The sample made connected soil sampling to be direction of depth in it, and continuity, durability, plant opal as a facies-fossil of pore system formed by roots were examined. Nishine district (in pine, swamp shrine and Egarinai 3 layer 13 〜 72 year:) and Iwate Kawaguchi district the research method where soil profile is located in known Mt. Iwatesan north It is older than (12 layer and … More 72000 years ago: Iwate Kawaguchi (it is four-layered) and volcanic ash soil of ball mountain ma (7 layers, temple forest (a layer)) were made to be an object. Soil sampling did the lower layer division in the age independence from the surface part where the layer that it is lamina profunda and is old existed. Pore images imaged the sample of the 4.2cm cube by X-ray and solid contrast radiography using contrast media (CH_2I_2). The durability of pore system formed by roots was shown in the degradation class (0: Soundness 1 : Slightness 2 : Inside-3 : Severity 4 : Disappearance) of pore. The outline of the result is shown in the following. The physical condition of the each trial soil texture was distributed from coarse sandy loam within the light clay, and dry density was high, and hydraulic conductivity was small, and it was the minute soil as volcanic ash. Pore images required in X-ray stereo-radiography was the distribution in which pore system formed by roots of the Nishine district was slight from the soundness. Surface part soil in the Iwate Kawaguchi was sound, when clear pore system formed by roots is shown, and when it is shown in the degradation class. Tamayama soil in the lower layer division intermingled to the severity in which the as degradation was close to the disappearance from the little slightness. Pore system formed by roots was not most shown Terabayashi soil in the lower layer division. The continuity of pore system formed by roots in the about 1m unit, there was the fluctuation, and there was the fluctuation over soil layer 1m soil layer small. And, the validity as a facies-fossil-ness was in the identification of the type of pore system formed by roots on the plant silicic acid. Though pore system formed by roots there was the continuity in the soil layer 720000 year ago of the prophase pleistocene series, when the above be summarized, and pore images was disappearing concerning the permeability in the part lower layer, there was the durability in the whole layer, and it also had the significance as a facies-fossil-ness. Less