Abstract Silicon (Si) is an important element for rice plant, and its availability in soil is an important factor affecting sustainable rice production. Herein, the distribution of available Si and its correlation with land-use type and soil-erosion status were investigated and discussed using the universal soil loss equation (USLE) in the Sumani watershed (SW). This watershed is the main rice-production area in Sumatra, Indonesia. Results showed that the available Si levels in sawah soil were less than 300 mg SiO2 kg−1 on average. Sawah means a leveled and bounded rice field with an inlet and an outlet for irrigation and drainage, respectively. Available Si content in river sediments was also studied and determined to be higher than those in sawah or other land-use types. This finding may indicate that available Si or soil rich in Si was redistributed through soil erosion. Soil-erosion rate was negatively correlated with the concentration of available Si in soils. Land-use types with smaller values of crop factor in USLE calculation and soil with lower pH showed relatively lower available Si in the soils. Overall, our findings indicated that soil erosion and land-use types affected the distribution of available Si in the watershed.

中文翻译：

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绘制印度尼西亚西苏门答腊土壤中有效硅分布的地球化学方法

摘要 硅（Si）是水稻植株的重要元素，其在土壤中的有效性是影响水稻可持续生产的重要因素。在此，利用苏马尼流域 (SW) 的通用土壤流失方程 (USLE) 调查和讨论了有效硅的分布及其与土地利用类型和土壤侵蚀状况的相关性。该流域是印度尼西亚苏门答腊的主要水稻产区。结果表明，sawah 土壤中的有效硅含量平均低于 300 mg SiO2 kg-1。Sawah 是指平整和有界的稻田，分别有一个入口和一个出口，用于灌溉和排水。还研究了河流沉积物中的有效硅含量，并确定其高于锯齿或其他土地利用类型中的含量。这一发现可能表明有效硅或富含硅的土壤通过土壤侵蚀进行了重新分配。土壤侵蚀速率与土壤中有效硅的浓度呈负相关。USLE 计算中作物因子值较小的土地利用类型和 pH 值较低的土壤显示土壤中的有效硅相对较低。总体而言，我们的研究结果表明，土壤侵蚀和土地利用类型影响了流域中有效硅的分布。