Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Li, Z. Articles by Li, D. Search for Related Content GeoRef GeoRef Citation

LOSS OF K-BEARING CLAY MINERALS IN FLOOD-IRRIGATED, RICE-GROWING SOILS IN JIANGXI PROVINCE, CHINA

¹ Institute of Soil Science, Chinese Academy of Sciences, 71 Beijing East Road, 210008, Nanjing, China
² Laboratoire de Géologie, CNRS 2113 Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris, France

^* E-mail address of corresponding author: papa{at}geologie.ens.fr

The loss of K-bearing clay minerals has been observed over an 80 y cultivation period in Chinese rice paddies despite the use of NKP fertilizers. Clay mineral determinations were made in flood-irrigated paddies cultivated for 3, 10, 15, 30 and 80 y in clayey (45 wt.%), red soils derived from red Quaternary sediments. Three clay minerals are initially present in these soils: illite-mica, magnesian chlorite and an interstratified mica-aluminous chlorite mineral. This last phase was identified using computer simulations . The K-bearing phases (discrete mica and illite as well as interstratified mica layers) are to a large extent lost while the Fe content decreases in the soil as a whole and increases in the chlorite. The mica component in the mixed-layer mineral decreases also. These changes in clay mineralogy and relative abundance suggest a loss of potassic minerals and an increase in the formation of less siliceous, more ferro-magnesian chlorite. These changes occur over 30 y or less, a rather rapid, irreversible transformation of soil clay minerals. Such loss of potassic minerals renders the cultivation more dependent on fertilizer amendment.

Key Words: Clay Mineral • Irrigation • Mica-chlorite Interlayer • Potassium

This article has been cited by other articles:

				Y.-l. Liu, B. Zhang, C.-l. Li, F. Hu, and B. Velde Long-Term Fertilization Influences on Clay Mineral Composition and Ammonium Adsorption in a Rice Paddy Soil Soil Sci. Soc. Am. J., September 30, 2008; 72(6): 1580 - 1590. [Abstract] [Full Text] [PDF]