湖北利川耕地土壤有效硅含量及空间分布

Effective Silicon Content and Spatial Distribution in Cultivated Land of Lichuan, Hubei Province

摘要: 采集、检测、统计并分析了湖北省利川市288个耕地土样的有效硅含量。结果表明：(1) 有效硅点位均值145.6 ± 87.4 mg/kg，变幅39.3~551.0 mg/kg，变异系数60.05%，中等变异。利川耕地有效硅整体含量较低，近80%的点位处于较低水平以下，约15%为中等，仅约5%在较高以上。(2) 行政区域和海拔垂直分布特征明显，由西北向东南呈降低趋势。西北部的谋道镇最高(227.8 mg/kg)，是东南部毛坝镇、沙溪乡(90 mg/kg上下)的2.5倍以上，并随海拔升高而升高。(3) 水旱不同利用方式对土壤有效硅影响较小，水田低于旱地，都在145 mg/kg上下。(4) 不同成土母质、土类及质地对耕地有效硅影响较大，含量差异明显。6种成土母质发育的耕地有效硅基本呈等差下降，碳酸盐岩(164.2 mg/kg) > 紫色页岩(152.3 mg/kg) > 石英砂岩(146.3 mg/kg) > 第四纪黏土(131.3 mg/kg) > 河流冲积物(124.1 mg/kg) > 泥质砂页岩(109.9 mg/kg)，最大值是最小值的1.5倍；7大土类基本分为4个阶梯，棕壤最高(近170 mg/kg)，其次是石灰土、紫色土在155 mg/kg上下，再次是黄棕壤、水稻土、潮土在143 mg/kg上下，最低为黄壤断崖式下滑到85 mg/kg，棕壤是黄壤的2倍；按质地统计基本分为3个阶梯，砂壤最高(近180 mg/kg)，其次是砂土、中壤、重壤、黏土由近160 mg/kg降至140 mg/kg，轻壤最低降至124 mg/kg，砂壤是轻壤的1.4倍。(5) 从统计学意义上看，利川耕地有效硅含量与土壤pH、阳离子交换量、交换性盐基总量、交换性钙镁呈极显著正相关，与有效磷呈极显著负相关。

Abstract: The effective silicon content of 288 cultivated land samples in Lichuan City, Hubei Province was collected, detected, statistically analyzed, and assessed. The results showed that (1) the average effective silicon sites were 145.6 ± 87.4mg/kg, with a range of 39.3~551.0 mg/kg and a coefficient of variation of 60.05%, indicating moderate variation. The overall effective silicon content in the cultivated land of Lichuan is relatively low, with nearly 80% of the points below a low level, about 15% being moderate, and only about 5% being above a high level. (2) The vertical distribution characteristics of administrative regions and altitude are obvious, showing a decreasing trend from northwest to southeast. The highest concentration in Mudao Town in the northwest (227.8 mg/kg) is more than 2.5 times that in Maoba Town and Shaxi Township in the southeast (around 90 mg/kg), and it increases with altitude. (3) The different utilization methods of water and drought have a relatively small impact on soil available silicon, with paddy fields being lower than dry lands, both around 145 mg/kg. (4) Different soil parent materials, soil types, and textures have a significant impact on the effective silicon content in cultivated land, with significant differences in content. The available silicon in cultivated land with 6 types of soil parent materials developed shows a basic equal decrease, with carbonate rocks (164.2 mg/kg) > purple shale (152.3 mg/kg) > quartz sandstone (146.3 mg/kg) > Quaternary clay (131.3 mg/kg) > river alluvial materials (124.1 mg/kg) > muddy sand shale (109.9 mg/kg), with the maximum value being 1.5 times the minimum value; The seven major soil types are basically divided into four tiers, with brown soil having the highest concentration (nearly 170 mg/kg), followed by lime soil and purple soil at around 155 mg/kg, followed by yellow brown soil, rice soil, and tidal soil at around 143 mg/kg, and the lowest being yellow soil with a cliff like decline to 85 mg/kg. Brown soil is twice as much as yellow soil. According to qualitative statistics, it can be divided into three steps. Sandy soil has the highest concentration (nearly 180 mg/kg), followed by sandy soil, medium soil, heavy soil, and clay, which decreased from nearly 160 mg/kg to 140 mg/kg. Light soil has the lowest concentration at 124 mg/kg, and sandy soil is 1.4 times that of light soil. (5) From a statistical perspective, the effective silicon content in Lichuan cultivated land is highly significantly positively correlated with soil pH, cation exchange capacity, total exchangeable salt base, and exchangeable calcium and magnesium, and negatively correlated with available phosphorus.