桂北地区不同母质发育水稻土农业生产潜力与重金属污染安全性评估OA

In the region of northern Guilin(Xing'an County and Lingchuan County),various profiles were excavated in areas with soil-forming materials such as alluvium,sandstone,limestone,and shale.A total of 15,10,5,and 7 profiles were identified respectively.The study involved recording profile morphology information,measuring soil physicochemical properties,and assessing heavy metal contents at different layers.By utilizing cultivated land quality grading evaluation and the single-factor pollution index method,a comprehensive evaluation was conducted to determine the overall production potential and heavy metal pollution risk.Results indicated that the rapidly available potassium content in paddy soils derived from the four parent materials was relatively low.Paddy soils originating from alluvial parent material exhibited the highest production potential,with 93.3%of the land classified as high or medium grade.These soils benefited from favorable terrain position,soil bulk density,and tillage layer texture,despite slightly weak nutrient conditions.Conversely,profiles developed from sandstone parent material faced limitations such as tillage layer thickness,texture,and irrigation capacity,resulting in 30.0%of the land classified as low-grade.Those from limestone parent material showcased strengths in pH,available phosphorus,and irrigation capacity,but were hindered by terrain position and effective soil layer thickness,with 80.0%categorized as high and medium grade.Paddy soils derived from shale parent material exhibited restricted production potential due to nutrient(organic matter,available phosphorus,and available potassium)deficiencies,resulting in 71.4%of the land being medium grade.In terms of safety,Cd poses the main risk,with single-factor pollution index values of 1.730,1.340,1.300,and 0.881 for sandstone,alluvium,shale,and limestone-derived soils,respectively.Overall,paddy soils in northern Guangxi are predominantly medium-grade,with production potential limited by site conditions,profile morphology,nutrient status,and farmland management,while Cd pollution remains the primary concern.It is advisable to implement tailored improvement strategies based on the various parent material types to enhance both rice soil production and ecological safety in the region in a coordinated manner.