Salt stress is a significant environmental factor that impedes maize growth and yield. Exogenous 5-aminolevulinic acid (ALA) has been shown to mitigate the detrimental effects of various environmental stresses on plants. However, its regulatory role in the photosynthesis mechanisms of maize seedlings under salt stress remains poorly understood. Transcriptome sequencing and physiological index measurements were conducted on the leaves of the “Zhengdan 958” cultivar subjected to three different treatments. Differential expression analysis revealed 4634 differentially expressed genes (DEGs), including key transcription factor (TF) families such as NAC, MYB, WRKY, and MYB-related, across two comparisons (SS_vs_CK and ALA_SS_vs_SS). Significant enrichment was observed in the metabolic pathways related to porphyrin metabolism, photosynthesis-antenna proteins, photosynthesis, and carbon fixation in photosynthetic organisms. ALA treatment modulated the expression of photosynthesis-related genes, increased photosynthetic pigment content, and enhanced the activities of superoxide dismutase (SOD) and catalase (CAT), thereby mitigating the excessive accumulation of reactive oxygen species (ROS). Furthermore, ALA increased starch content under salt stress. These findings establish a foundational understanding of the molecular mechanisms through which ALA regulates photosynthesis under salt stress in maize seedlings. Collectively, exogenous ALA enhances maize’s salt tolerance by regulating photosynthesis-related pathways.

Accurate soil management has long been the focus of research in agroecology. Crop productivity can be enhanced while reducing environmental threats from excessive fertilization by fully comprehending the spatial variability of soil properties and delineating management zones (MZs). A field investigation was carried out at experimental sites outside Hefei City’s administrative districts in China to study the spatial variability of soil properties and the delineation of MZs. A total of 9601 soil samples were collected in the study area. A variety of soil properties were analyzed, including the pH, organic matter, total nitrogen, alkali-hydrolyzable nitrogen, available phosphorus, available potassium, slowly released potassium, available sulfur, available boron, available copper, available zinc, available iron, and available manganese. The coefficient of variation for various soil properties exhibited a wide range, spanning from 12.2% to 100.5%. The geostatistical results show that most soil properties have moderate to strong spatial autocorrelation, and the ordinary kriging method is used to map the distribution of soil properties. The principal component analysis method was used to reduce the dimension of 13 soil properties to 4 principal components, and the fuzzy c-means clustering method was used to delineate MZs. The calculation results of the fuzzy performance index and normalized classification entropy show that the optimum number of MZs is five. In the study area, the western part exhibits the highest soil fertility, primarily attributed to its elevated organic matter content. Additionally, organic matter emerges as a key factor influencing sustainable agricultural production in this region. These results form the basis for soil managing areas outside the administrative districts of Hefei City.

Understanding the complex variations in water use efficiency (WUE) is critical for optimizing agricultural productivity and resource management. Traditional analytical methods often fail to capture the nonlinear and multiscale variations inherent in WUE, where multifractal theory offers distinct advantages. Given its limited application in WUE studies, this paper analyzes the spatiotemporal characteristics and influencing factors of the WUE in Anhui Province from 2001 to 2022 using a multifractal, multiscale approach. The results indicated that the WUE exhibited significant interannual variation, peaking in summer, especially in August (2.4552 gC·mm⁻¹·m⁻²), with the monthly average showing an inverted “V” shape. Across different spatial and temporal scales, the WUE displayed clear multifractal characteristics. Temporally, the variation in fractal features between years was not prominent, while inter-seasonal variation was most complex in August during summer. Spatially, the most distinct multifractal patterns were observed in hilly and mountainous areas, particularly in regions with brown soil distribution. Rainfall was identified as the primary natural driver influencing regional WUE changes. This study aims to promote the sustainable use of water resources while ensuring the stability of agricultural production within protected farmlands.

Understanding differences in soil organic carbon (SOC) stocks among reclamation modes is essential for evaluating ecological recovery in reclaimed croplands. However, the factors associated with these differences remain poorly understood in coal-mining subsidence areas with high groundwater tables. We investigated croplands reclaimed 25 years before sampling under three reclamation modes in eastern China: coal gangue backfilling reclamation (CGBR), fly ash backfilling reclamation (FABR), and deep excavation–shallow filling reclamation (DESFR), with unaffected cropland serving as the reference (CK). Soil samples were collected from three layers (0–15, 15–30, and 30–45 cm) to assess SOC stocks, labile carbon fractions, water-stable aggregates, hydrolytic enzyme activities, and bacterial communities. Correlation analysis, random forest modeling, and exploratory partial least squares path modeling were used to examine associations between SOC stocks and soil properties. Soil carbon pools and bacterial communities varied among reclamation modes and soil layers. SOC stocks in the 0–45 cm profile were 70.35, 65.05, and 51.78 Mg C ha⁻¹ under CGBR, FABR, and DESFR, respectively. Among the evaluated reclamation modes, CGBR had the highest mean SOC stock, equivalent to approximately 98.2% of the reference cropland (CK) level and 8.15% and 35.86% higher than those under FABR and DESFR, respectively. DESFR had the lowest SOC stock despite relatively high aggregate stability. Exploratory analyses indicated associations of SOC stocks with carbon and nitrogen availability, hydrolytic enzyme activities, bacterial diversity, and aggregate properties. These findings support considering soil ecological recovery alongside engineering performance when evaluating reclamation effectiveness in the studied subsidence area. Long-term monitoring and multisite observations are needed to characterize SOC recovery trajectories and assess the broader applicability of these findings.