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| 3种水稻土时间序列黏粒矿物的组合特征与物源指示意义 | |
| 引用本文： | 韩光中.3种水稻土时间序列黏粒矿物的组合特征与物源指示意义[J].地理科学,2016,36(8):1277-1284. |
| 作者姓名： | 韩光中 |
| 作者单位： | 1.内江师范学院地理与资源科学学院,四川 内江 641112 2.中国科学院南京土壤研究所/土壤与农业可持续发展国家重点实验室,江苏 南京 210008 |
| 基金项目： | 国家自然科学青年基金项目（41401235）、四川省教育厅重点项目（14ZA0241）、国家级大学生创新实验项目(X201306)资助 |
| 摘 要： | 对南方丘陵区3种不同母质水稻土时间序列黏粒矿物的X-射线衍射（XRD）进行分析发现：① 紫色砂页岩（PS）母质起源土壤的黏粒矿物以高岭石类似矿物为主;第四纪红黏土（RC）母质起源土壤的黏粒矿物以高岭石类似矿物、伊利石类似矿物与三羟铝石为主;红砂岩（RS）母质起源土壤的黏粒矿物以1.4 nm过渡矿物、高岭石类似矿物与三羟铝石为主。② 这3种母质土壤种稻后黏粒矿物的变化大体可分为2种情况。RC与RS母质的起源土壤种稻后,土壤黏粒矿物的变化相对较小,伊利石类似矿物相对含量有所增加,这可能主要与钾肥的持续施用有关。PS母质的起源土壤种稻后,土壤黏粒矿物变化相对较大,表现为高岭石类似矿物相对含量降低,低结晶度的伊利石或次生绿泥石与三羟铝石相对含量上升。PS母质发育的土壤种稻后脱钾明显且主要集中在原生矿物部分。这种原生矿物的脱钾作用对土壤黏粒含量和黏粒矿物的类型都有较大影响。③ 起源土壤的黏粒矿物通常会被水稻土所继承,并在水稻土发育过程中相对稳定,可以用其来指示起源土壤（或母质）的物源组分。 |
| 关 键 词： | 水稻土（水耕人为土） 时间序列 母质 黏粒矿物 物源 |
| 收稿时间： | 2015-11-03 |
| 修稿时间： | 2016-01-14 |
Clay Mineral Assemblages and Their Provenance Implications of Three Paddy Soil Chronosequences |
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| Guangzhong Han.Clay Mineral Assemblages and Their Provenance Implications of Three Paddy Soil Chronosequences[J].Scientia Geographica Sinica,2016,36(8):1277-1284. | |
| Authors: | Guangzhong Han |
| Institution: | 1.College of Geography and Resources Science of Neijiang Normal University, Neijiang 641112, Sichuan, China 2. State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, Jiangsu, China |
| Abstract: | Paddy soils (Hydragric Anthrosols) greatly differ from their parent soils and homologous Orthic Anthrosols in physical and chemical properties, owing to their special soil formation processes. This prevented discriminating their provenance by conventional means. Paddy terraces in the hilly regions of South China are an example of successively expanding cultivated lands in a sustainable system. Because of their depth, fertility and ease of irrigation, soils at the bottom of slopes were generally the first to be converted to paddy; as population pressure increased, lands upslope were progressively brought into paddy cultivation. Thus, these hillside terraces, with increasing cultivation age from the top to the bottom of the slopes, form soil chronosequences. Considering the constraints, three paddy soil chronosequences derived from the main parent materials of the region in the hilly regions of South China, namely, purple sandy shale (PS), Quaternary red clays (RC) and red sandstone (RS), were selected to explore the clay mineral assemblages and their provenance implications. The XRD pattern suggested that kaolinite-like clays were major constituents of the PS soils. Similarly, illite-like, kaolinite-like and bayeritewere major constituents in the RC soils, and 1.4 nm intergradient minerals, kaolinite-like and bayerite were major constituents in the RS soils. For RC and RS soils, there was little change in the clay minerals. Long-term paddy cultivation can promote formation of illite-like minerals. In PS soils, the depotassication was strong, accompanied by marked transformation of clay minerals. Kaolinite-like minerals gradually decreased with paddy cultivation age; by contrast, derivative clay minerals such as secondary chlorite and halloysite gradually increased. Strong depotassication mainly occurred in the non-clay fractions. The results also indicated the clay minerals of paddy soils mainly followed the feature of their original soils and that their evolutions could be roughly distinguished based on their constituents. For soils with a low content of K-bearing minerals, there was little change in clay mineralogy. For soils that were abundant in K-bearing minerals, depotassication was strong and the change in clay minerals was comparatively remarkable. This result suggests that the evolution of clay minerals is primarily affected or determined by their original soils derived from different parent materials. In addition, the crystallinity of illite-like minerals would be worse under the long-term paddy cultivation and periods of artificial submergence with highly activity in hydrolysis might cause the change of the ordering degree of lattice of clay minerals. However, the projections of main clay minerals for paddy soils from same parent material centralized in a lesser range and the clay mineral assemblages can reflect their parent material sources in paddy soils. |
| Keywords: | paddy soils (Hydragric Anthrosols) soil chronosequences parent materials clay minerals provenance |
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