The impact of high-temperature treatments on maize growth parameters and soil nutrients: A comprehensive evaluation through principal component analysis

In contrast to prolonged exposure to high temperatures, investigating short-term high-temperature stress can provide insights into the impact of varying heat stress durations on plant development and soil nutrient dynamics, which is crucial for advancing ecological agriculture. In this study, five heating temperatures were set at 200°C, 250°C, 300°C, 350°C, and 400°C, along with five heating time gradients of 6s, 10s, 14s, 18s, and 20s, including a control. A total of 26 treatment groups were analyzed, focusing on maize growth parameters and soil indicators. Principal component analysis was used for comprehensive evaluation. The results showed that high-temperature treatments with different heating times significantly influenced maize growth and soil properties. For instance, the treatment of 300°C+6s resulted in the longest total root length, while 200°C+6s led to the highest average root diameter. Plant height and leaf length were notably increased with the treatment of 400°C+6s. Most treatments resulted in decreased soil pH and organic matter content. Notably, the treatment of 350°C+16s showed the highest available phosphorus content, reaching 24.0 mg/kg, an increase of 4.5 mg/kg compared to the control. The study found that the average levels of active organic carbon and peroxidase were 1.26 mg/g and 3.91 mg/g, respectively. Additionally, the average mass fractions of clay, silt, and sand particles were 8.99%, 66.75%, and 24.26%, respectively. Through principal component analysis, six principal components were able to extract 19 indicators from the 26 treatments, covering 86.129% of the information. It was observed that 16 treatment methods performed better than the control in terms of soil comprehensive quality. The optimal treatment temperature and time identified for improving soil physicochemical properties and crop growth were 300°C+6s. These findings can be used to guide agricultural management and soil improvement practices, ultimately enhancing field productivity and providing valuable insights for sustainable agricultural development.