Evaluation of natural- and agro-ecosystem by soil chemistry

通过土壤化学评估自然和农业生态系统

• 批准号: 08660077
• 负责人: SAKURAI Katsutoshi
• 金额: $ 1.66万
• 依托单位: Kochi University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08660077/
• 关键词: Nihon-sida grassland; reclaimed land; soil microorganisms; fungi; bacteria; low molecular weight organic acids; water-stable aggregate; 耐水性団粒; 農業生態系; 日本シバ草地; 土壌溶液; 環境水; 荷電ゼロ点; 草地の塾畑化; 土壌硬度; 自然肥沃度

In1996, study site was selected from several types of land use to investigate geomorphlogical and morphological properties of the soils. Soil samples were collected there. Water samples were also collected from the surrounding area. Items for soil analysis were as follows ; Physical : texture, three phase distribution, saturated hydraulic conductivity, Chemical : exchangeable cations (Ca, Mg, Na, and K), exchangeable Al and H,cation exchange capacity, available phosphorus, total carbon and nitrogen, pH (H_2O and KCl), Charge : zero point of charge, sigmap, Mineralogy : Tamm and DCB extractable oxides and hydroxides, clay mineralogy. Soil hardness and hydraulic conductivity were measured in the field on May, September, and December in 1996.In 1997, we had conducted monitoring in grassland in view of microorganisms, soil solution composition, pH and EC.We measured soil hardness and collected fresh soils on June, September, December in 1997. Actinomycetes and fungi were counted using dilute plate method. On the other hand, we evaluated the low molecular weight organic acids with air dried soils. Comparing older grassland with younger grassland and natural forest, we found that (1) the old grassland had a little water-soluble nutrients, (2) showed no difference between surface and subsurface soils, and (3) had stable soil condition to circulate nutrients and water within the depth of 5 to 20cm.

1996年，从几种土地利用类型中选择了研究地点，以调查土壤的地貌和形态特性。土壤样本在那里采集。还从周边地区采集了水样。土壤分析项目如下：物理：结构、三相分布、饱和导水率、化学：交换性阳离子（Ca、Mg、Na、K）、交换性Al、H、阳离子交换容量、有效磷、总碳、总氮、pH（H_2O、KCl） ，电荷：零电荷点，sigmap，矿物学：Tamm 和 DCB 可提取氧化物和氢氧化物，粘土矿物学。 1996年5月、9月、12月在田间测量了土壤硬度和导水率。1997年对草地进行了微生物、土壤溶液成分、pH、EC等监测。测量了土壤硬度并采集了新鲜土壤1997年6月、9月、12月。采用稀平板法对放线菌和真菌进行计数。另一方面，我们用风干土壤评估了低分子量有机酸。比较古老的草地与年轻的草地和天然森林，我们发现：（1）古老的草地有少量水溶性养分，（2）表层和地下土壤没有差异，（3）具有稳定的土壤条件以循环养分水深5至20厘米。