Clay mineralogical composition of tea [Camellia sinensis] garden soils in Shandong Province, China

For assistance of the appropriate plant-nutrient management practice to keep the sustainable tea production in Shandong Province, particle-size and clay mineral analyses were carried out to the surface layer of soils collected in tea gardens of Laoshan region of Qingdao City and Dahainanchun region of Jimo City, Shandong Province, People's Republic of China. Variation of the particle-size distribution with sites was small in each region. The clay content ranged from 17.6 to 22.7% for soils from Laoshan region and from 16.1 to 18.6% for soils from Dahainanchun region, and the texture was clay loam for the former and sandy clay loam for the latter. All the soils showed the similar X-ray diffraction patterns of the clay fraction, and vermiculite, mica, serpentine and quartz were identified in common. Among them, vermiculite was predominant followed by mica and serpentine. Similarity in the clay mineralogical composition, along with the regional similarity in the particle-size distribution, suggests origination of soils from eolian dust in an extensive area and is easy for the comprehensive performance of the plant-nutrient management practice to soils in the tea garden in Shandong Province.