Background
The long-term food security of Indo-Gangetic Plain depends heavily on the resilience of alluvial soil, which face compounding pressures from intensive multi-cropping and seasonal climatic extremes. Soil is a fundamental natural resource that supports agricultural productivity and seasonal changes are among the most important factors influencing soil chemical characteristics. We hypothesize that soil physicochemical characteristics in the study area would exhibit significant seasonal variation. Hence, our objective was to study the seasonal variation in the soil physical and chemical properties of the major agricultural fields in the Lucknow district and to infer the principal components responsible for the specific soil characteristics of a particular crop field. The study will provide insights into soil characteristics across different crop fields and assist farmers, researchers, and policymakers in crop management, thereby improving crop yields.

Methods
The district is divided into 8 blocks, of which 6 were selected for soil sampling during 2023‒2025. Wheat, paddy, and mustard crop fields having major cover were selected for the study. Soil samples were collected from selected crop fields in each block, in replicate, on a seasonal basis, and brought to the laboratory for analysis following the standard methods.

Results
The texture of soil was sandy clay loam, loam, and sandy clay with an average 45% of sand, 30% clay, and 25% silt. The available nitrogen content was high across all sites, ranging from 102.23 kg/ha to 396.08 kg/ha. Available potassium ranged from 125 to 300 kg/ha, and available phosphorus from 7.53 to 34.3 kg/ha. Seasonal variation was found to be significant in the sand (F2,61, = 177.64, p < 0.001) and clay (F2,61 = 68.22, p < 0.001).

Conclusion
The study will help farmers, researchers, and policymakers in crop management to improve yield, and include new ways for sustainable agriculture. The findings will support evidence-based soil management strategies, enhance agricultural productivity, and contribute to the scientific understanding of soil chemical processes.