基于最小数据集的吉林省黑土耕层土壤质量评价

黑土作为吉林中部平原粮食主产区主要土壤类型,其质量的优劣直接影响区域生态安全和农业可持续发展。该研究以吉林省典型黑土耕层土壤作为研究对象,采集1 401个土壤样本,测定8项土壤理化指标及玉米产量。采用最小数据集法筛选评价指标,对于黑土耕层土壤进行质量评价,并综合土壤质量指数和产量提出评价指标的适宜范围。结果表明:吉林省黑土耕层土壤质量评价最小数据集由耕层容重、有机质、速效磷、pH构成,由全量数据集(Total Data Set,TDS)、重要数据集(ImportantDataSet,IDS)和最小数据集(MinimumDataSet,MDS)分别计算的土壤质量指数之间存在显著正相关关系,R~2分别为0.716、0.771,表明MDS可以替代TDS对黑土耕层土壤质量进行评价。黑土玉米种植区耕层土壤质量指数分布在0.22～0.75之间,均值为0.53,呈现东部高西部低的趋势。土壤质量指数随产量先增加后降低。黑土耕层保持较高土壤质量及产量的评价指标适宜范围分别为:容重为1.23～1.43 g/cm3,酸碱度(pH值)为4.74～6.96,有机质为33.14～35.81 g/kg,有效磷为122.46～136.06 mg/kg。该研究结果可为吉林省黑土耕层土壤质量诊断、提高黑土肥力及选择适合农田管理措施提供理论及参数支撑。

Soil quality evaluation in topsoil layer of black soil in Jilin Province based on minimum data set

Abstract: Soil quality refers to the comprehensive capacity of soil, covering three aspects of maintaining productive capacity, protecting environmental quality and promoting animal and plant health, which can sensitively reflect the dynamic changes of soil conditions and soil management. Soil quality assessment, is the quantitative expression of soil intrinsic properties, which can be reflected through soil physical, chemical and biological properties. As the main soil type in the main grain production area of the central plain of Jilin, the quality of black soil directly affects the regional ecological security and sustainable agricultural development. In this study, the typical black soil in Jilin Province was taken as the research object, 1401 soil samples were collected, and 8 soil physical and chemical indexes and corn yield were determined. The minimum data set (MDS) method was used to screen the evaluation indicators, the quality of the black soil was evaluated, and the suitable range of soil parameters was proposed by combining the Soil Quality Index (SQI) and the yield. The results showed that the surface soil nutrient of black soil maize growing area in Jilin Province was above medium level, soil acidification was obvious, and the variation coefficient of soil chemical index was greater than that of physical index. MDS for soil quality evaluation of black soil in Jilin Province consists of soil Bulk Density (BD), Organic Matter (SOM), Available Phosphorus (AP), and pH value. The filtering rate of indicators reached 50.0%, which significantly simplified the evaluation index system and eliminated the influence of information overlap among indicators on the evaluation results to the greatest extent. There were significant differences between the soil quality indexes calculated from the Total Data Set (TDS), the Important Data Set (IDS) and MDS. The mean value of SQI-TDS was equal to the SQI-MDS, indicating that the screened MDS can replace TDS to evaluate the soil quality of the black soil maize field. The SQI of the cultivated layer in the black soil corn planting area was distributed between 0.22 and 0.75, the average value was 0.53, showing a high trend in the east and a low trend in the west. There was a significant correlation between the SQI and the yield (R2=0.514), which showed that the soil quality index increased firstly and then decreased with the yield, further proving that the MDS was scientific in evaluating soil quality, and the pursuit of yield should not be at the cost of soil quality. The optimum range of soil parameters for maintaining higher soil quality and yield in topsoil layer of black soil was 1.23-1.43 g/cm3 for BD, 4.74-6.96 for pH, 33.14-35.81 g/kg for SOM, and 122.46-136.06 mg/kg for AP. BD and pH in the study area are within the appropriate range, and the improvement of SOM and AP content should be realized through straw returning, rational application of organic fertilizer and phosphorus fertilizer. The results could provide theoretical and parameter support for the diagnosis of black soil quality, improvement of black soil fertility and selection of suitable farmland management measures in Jilin Province.