Abstract:

Based on soil moisture data, meteorological data and soil texture data from 37 high−standard farmland stations in Henan province from 2020 to 2023‌, this study employed regularity analysis to investigate the variation patterns of soil gravimetric water content across 8 soil depth layers (10−100cm), characteristics of soil water storage changes and responses of different soil textures to varying precipitation intensities during the period from regreening to maturity of winter wheat in Henan. The objectives were to provide scientific references for optimizing soil water utilization efficiency and formulating targeted farmland management strategies in high−standard agricultural systems. The results showed that: (1) during regreening to maturity period of winter wheat in Henan high−standard farmland (2020–2023), the soil gravimetric water content of the 10−60cm layer increased with soil depth. In contrast, the 10−50cm layer exhibited a gradual decreased in gravimetric water content as the growth stage progressed, with the 10cm surface layer showing the most significant reduction (a decrease of 3.5pp). (2) During regreening to maturity period of winter wheat from 2020 to 2023 in Henan high−standard farmland, when the precipitation anomaly percentage was positive, soil water storage at various layers predominantly showed an increasing trend. Conversely, a negative precipitation anomaly percentage was associated with a general decrease in soil water storage at various layers. (3) Throughout the study period, the soil gravimetric water content across three soil textures followed the order: clay soil (17.7%–23.8%) > loam (16.4%–20.9%) > sandy soil (10.3%–16.2%). While the coefficient of variation ranked as sandy soil (0.32−0.53) > loam (0.25−0.38) > clay soil (0.22−0.34). Sandy soils exhibited the highest variability in soil gravimetric water content, while clay soils showed the lowest fluctuations. Across all three soil textures, the 10 cm depth layer exhibited the strongest moisture variability. (4) The response of soil gravimetric water content to precipitation events decreased with increasing soil depth across three soil textures, while the penetrable water depth increased with precipitation intensity. Loam and clay soil showed a more pronounced hysteresis effect in moisture response to precipitation compared to sandy soil. Under heavy rainfall conditions, sandy soil gravimetric water content reached peak on the day of precipitation and returned to pre−precipitation levels within 5 days. In contrast, loam and clay soil achieved maximum moisture increments 2 to 5 days after precipitation and failed to recover to pre−precipitation levels within 7 days. Overall, sandy soil responded rapidly to precipitation but retained water for a shorter duration and have poor water retention, whereas clay soil responded more slowly but retain higher moisture for longer periods, demonstrating superior water retention.

Key words: High?standard farmland, Soil gravimetric water content, Soil textures, Precipitation level