基于养分指标相关性的土壤有机质预测模型研究

为探究土壤间各养分指标间的相互关系,选取了天津市宁河区不同区域的种植土壤,基于行业标准规定的检测方法,对主要养分指标进行了测定,并研究各指标间的相关性。结果表明,各区域土壤pH值变异系数最小,整体均呈碱性；有机质、全氮及速效钾变异系数属于中等；有效磷的变异系数最高。各研究区域土壤有机质含量与全氮含量呈显著正相关(P<0.01),与pH值呈显著负相关(P<0.01),而与其他指标间不具备普遍且显著的相关性。基于多元线性回归分析建立了土壤有机质与全氮及pH值之间的预测模型,通过模型计算出的预测值与实际测定值的拟合性较好；另取土壤样品进行验证表明,预测模型具有良好的可靠性和准确性。

Study on the prediction model of soil organic matter based on correlation of nutrient indexes

To explore the relationship between soil nutrient indexes, the planting soils from different study areas in Ninghe District of Tianjin were selected, whose nutrient indexes were measured based on detection methods stipulated in agricultural standard. The correlation between nutrient indexes was analyzed by Statistical Software. The results showed that the variation coefficient of pH value in each study area was the smallest, and all soil samples were alkaline. The variation coefficients of organic matter, total nitrogen and available potassium were moderate. The variation coefficient of available phosphorus was the highest. There was a significant positive correlation between soil organic matter content and total nitrogen content ( P < 0.01 ), and a significant negative correlation with pH value ( P < 0.01 ). But there was no prevalent and significant correlation between soil organic matter content and other nutrient indexes. Based on multiple linear regression analysis, a prediction model of soil organic matter was established with total nitrogen and pH value. The predicting values calculated by the model were in good agreement with actual measured values. In addition, the validation with three nutrient indexes of soil samples from different study areas showed that the prediction model had good reliability and accuracy.