安徽省土壤有效硫现状及时空分布

Current situation and spatial-temporal distribution of soil available sulfur in Anhui Province

【目的】土壤有效硫是作物硫素营养的主要来源,在获取省域范围耕地土壤有效硫基础数据和硫肥试验研究结果的基础上,以地统计学特征分析和新的土壤有效硫分级指标统计为手段,研究全省土壤有效硫时空变化特点和区域性分布现状,掌握全省耕地土壤硫养分丰缺状况及供给水平,为科学施肥提供依据。【方法】选择安徽省砂姜黑土、潮土、黄褐土、水稻土等11个土类,采集农田0—20 cm耕层土样34.5万个。通过大样本数据的统计分析,利用ArcGIS进行Kriging插值的地统计学分析,按照本省耕地土壤有效硫新的丰缺分级标准,即极缺(<10.0 mg/kg)、缺乏(10~16 mg/kg)、较缺乏(16~22 mg/kg)、中等(22~34 mg/kg)和丰富(> 34mg/kg)五级,结合第二次土壤普查分级指标对应分析,进行省域耕地土壤有效硫丰缺现状和时空分布研究。【结果】1)全省耕地土壤有效硫含量范围在0.10~101.90 mg/kg之间,平均值为24.99 mg/kg,中位数为21.00mg/kg。2)全省耕地土壤缺硫概率较大。有效硫含量处于极缺(<10 mg/kg)、缺乏(10~16 mg/kg)与较缺乏(16~22 mg/kg)水平的分别占总样本数的13.76%、20.91%和18.43%。3)省域总体缺硫状况由东向西递增、南北向中间趋减。按不同农业区域比较,淮北平原的宿州、亳州和阜阳市缺硫最严重,其次是皖南山区,又以黄山市、铜陵市土壤缺硫较严重。4)土壤类型和时空变化上,以棕壤、黄潮土、粗骨土、红壤、黄壤、紫色土和砂浆黑土等缺硫最为严重。与20年前研究分析比较,沿江平原、江淮丘陵和皖西农区缺硫趋势减弱,而皖南山区土壤缺硫状况明显加重。目前,棕壤、砂姜黑土和黄棕壤缺硫频率和风险增大,而黄潮土、黄褐土和灰潮土缺硫频率降低。【结论】省域耕地缺硫(<22 mg/kg)面积约311.19×10~4 hm^2,占全省耕地总面积的53.10%。针对棕壤、砂浆黑土、黄潮土、红壤等九类土壤缺硫比率高(39.67%~56.89%之间)的现状,应推荐含硫化肥或补施硫肥,降低作物缺硫风险。

【Objectives】Soil available sulfur(S)is the main source for plant S nutrition.The regional soil sulfur efficiency of the arable land in Anhui Province was systematically studied so as to provide reference for scientific application of S fertilizers and the balanced fertilization.【Methods】345 thousands of soil samples were collected from 0–20 cm soil layers around Anhui Province.The covered soil types included fluvo-aquic soils,lime concretion black soils,yellow-cinnamon soils and paddy soils etc.The spatial-temporal distribution of soil available S content was analyzed using large sample data and Kriging interpolation on ArcGIS platform.【Results】1)Soil available S was in the range of 0.10–101.90 mg/kg with a mean of 24.99 mg/kg and a median of 21.00 mg/kg.2)Soil available S was generally insufficient,53.1%of the total samples were deficient in soil available S(<22 mg/kg).3)The situation of soil available S deficiency increased from east to west and from middle to south and north.4)The soil available S deficiency became worse in brown soils,yellow fluvoaquic soils,skeleton soils,red soils,yellow soils,purple soils and lime concretion black soils.Compared with 20 years ago,soil available S deficiency was alleviated along the Changjiang River Plain,Jianghuai Hill and West Anhui,but became more serious in south Anhui.At present,the frequency and risk of soil available S deficiency increased in brown soils,lime concretion black soils and yellow-brown soils,but decreased in yellow fluvo-aquic soils,yellow-cinnamon soils and grey fluvo-aquic soils.【Conclusions】The arable land area with soil available S deficiency(<16 mg/kg)and relatively deficiency(16–22 mg/kg)was about 311.19×104 hm2,accounting for 53.1%of the total cultivated land in Anhui Province.Considering the high ratio(39.67%–56.89%)of soil available S deficiency(<16 mg/kg)in the 9 soil types including brown soils,lime concretion black soils,yellow fluvo-aquic soils and red soils etc.,S fertilizers should be applied to decrease the risk of crop S deficiency.