Effects of Soil Degradation on the migration of Environmental Materials in an Agricultural Field.

本研究的目的是：（1）找出原因，为什么最近在福冈、Saitama地区380公顷的油田中土壤严重退化， （2）分类土壤退化对这种环境材料迁移的影响，如水、溶液（包括盐、硝酸盐、磷酸盐等），and gasses （including OイイD22イエD2，COイD22イエD2， NイD22イエD2O etc.），和（3）根据土壤恢复的物理性质和土壤的效率，提出了恢复土壤的方法，主要结果如下。从水库字段中的排水效率和过剩水的测量中得到的缓解并不只是土壤退化，但也是结构的结构结构如道路、排水运河、绿色房屋等。The saturated hydraulic conductivities of soil samples from well drained fields were not necessary higher than those from poorly drained fields。这一对比是由土壤的其他物理性质解释的。从紫外线场抽取的不良效率受到聚合稳定性低、对盐的应用敏感性高、对表面结壳的容易到形式的趋势和高一致性的影响。土壤退化被分类为两种类型：一种是表面土壤退化的地方，土壤在机械上分散、直接紧凑和周期性腐蚀的地方，另一种是底层土壤退化的地方，土壤在体积密度的增加中间接紧凑的结果。深度提取对地下土壤的恢复是有效的，但提取与有机物质并没有显示出土壤的物理性质的任何优势。聚丙烯酰胺（PAM）的应用可能对土壤的恢复具有有效的效果。需要对PAM有效性的进一步调查。

The purpose of this study were to (1) find the causes why soils are undergoing serious degradation recently in the 380 ha upland fields in Fukaya, Saitama Prefecture, (2) classify the effects of soil degradation on the migration of such environmental materials as water, solutes (including salts, nitrogen, phosphorous, etc.), and gasses (including OィイD22ィエD2,COィイD22ィエD2, NィイD22ィエD2O etc.), and (3) propose the ways of soil restoration by which physical properties and drainage efficiency of the soils are recovered.The main results are as follows.1. The suffering from deterioration of drainage efficiency and excess water in upland fields were due to not only by soil degradation but also configurations of structures such as roads, drainage canals, green houses etc.2. The saturated hydraulic conductivities of soil samples from well drained fields were not necessary higher than those from poorly drained fields. This contradiction was explained by other physical properties of soils.3. The poor efficiency of drainage from upland fields were attributed to the low stability of aggregation, high sensitivity to the application of salts, the tendency of easy-to-form surface crusts, and high consistencies.4. The soil degradation was classified into two types : one is the surface soil degradation where the soils are mechanically disturbed, directly compacted and periodically fertilized, and other is the subsurface soils degradation where the soils are indirectly compacted resulting in the increase of bulk density.5. The deep plowing was effective for the restoration of subsurface soils but plowing with organic matter did not show any advantage for the physical properties of soils.6. Application of polyacrylamid (PAM) may be effective for the soil restoration especially in its permeability. Further investigation of the PAM efficiency is needed.