海南农田土壤中硅的含量及其空间分布

为全面了解海南农田土壤中硅的分布状况及喜硅作物的挖掘开发提供依据,采集海南18个市县的169个农田土壤表层(0~20cm)样品,按照《区域生态地球化学评价样品分析技术要求(试行)》采用比色法测定土壤全硅和有效硅含量,并进行分级评价。结果表明:海南农田土壤有效硅含量为3.85~340.34mg/kg,平均为63.9mg/kg,有效硅属于中度缺乏状态,各市县农田土壤有效硅的含量差异较大,空间上呈以琼北地区为中心向四周逐渐降低的发射状分布,东方与乐东交界地区、白沙的西北地区和定安的局部地区是全岛农田土壤有效硅含量最低的地方;农田土壤全硅含量为135.52~572.26g/kg,平均为426.46g/kg;空间上与土壤有效硅呈互补状态。

Content and Spatial Distribution of Silicon in Farmland Soil in Hainan

The total silicon and available silicon content of 169 surface soil samples collected from 18 cities (counties) in Hainan were determined and evaluated by the colorimetric method according to "Technical Requirements for Sample Analysis of Regional Ecological Geochemical Assessment (for Trial)"to overall understand the silicon distribution status in farmland soil and to provide the basis for developing silicon-requiring crops in Hainan.Results:The available silicon content of farmland soil is 3.85 ～340.34 mg/kg with an average of 63.9 mg/kg,which indicates the available silicon content of farmland soil is at a moderate deficiency level.There is an obvious difference in soil available silicon content between different cities (counties).The spatial distribution of soil silicon content gradually decreases from Qiongbei region to all around cities (counties) in a radial distribution pattern and the regions with the lowest soil available silicon content are the borders between Dongfang City and Ledong County,northwestern Baisha County and local area in Ding'an County in Hainan.The total silicon content of farmland soil is 135.52～572.26 g/kg with an average of 426.46 g/kg.There is a complementary status in the space between soil total silicon and soil available silicon.