Water scarcity and low soil fertility represent significant limitations to productivity within the dryland farming systems of the Loess Plateau. Consequently, optimizing summer fallow management to improve soil water retention and fertility is critical for enhancing soil quality in this region. To assess the maximum efficiency of rainfall capture during the summer fallow period, elucidate its interactions with soil microbial communities, and clarify the mechanisms underlying yield enhancement, a two-year field experiment was conducted. This study evaluated several treatments applied during the summer fallow: organic fertilizer alone (OF); organic fertilizer combined with deep tillage (OD); organic fertilizer with deep tillage and furrow-ridging (ODR); organic fertilizer with deep tillage, furrow-ridging, and plastic film mulching (ODRP); and organic fertilizer with deep tillage, furrow-ridging, and biodegradable film mulching (ODRB). Compared to conventional farmer practice (FP), the optimized rainfall management (ODRP) implemented in early summer fallow increased winter wheat grain yield by an average of 26.3 %, with spike number identified as the primary yield determinant. Between 2022 and 2024, the average efficiency of summer fallow rainfall storage under the OF, OD, ODRP, and ODRB treatments exceeded that of the FP treatment by 4.5 %, 36.3 %, 48.1 %, and 27.0 %, respectively. Notably, the ODR treatment reduced rainfall storage efficiency by 25.1 % relative to OD. The application of organic fertilizer during early summer fallow enhanced soil organic carbon content in the 0–40 cm soil profile by 8.8–24.8 % in the 0–20 cm layer and by 17.8–46.7 % in the 20–40 cm layer. Improved water and nutrient availability during the summer fallow period led to a decrease in the relative abundance of oligotrophic bacteria (Acidobacteria) and an increase in copiotrophic bacteria (Firmicutes). Correlation analyses demonstrated significant positive associations among soil moisture, Firmicutes abundance, and winter wheat yield. Partial least squares path modelling, coupled with Monte Carlo uncertainty analysis, identified soil moisture as the principal factor influencing yield formation via its effect on spike number, accounting for 63 % of the yield variability. Additionally, soil moisture and microbial metabolic activity contributed to organic carbon sequestration. In summary, maximizing rainfall-harvesting efficiency during the summer fallow period in conjunction with organic fertilizer application, constitutes a crucial strategy for promoting sustainable and high-quality agricultural development in the dryland wheat systems of the Loess Plateau.
扫码关注我们
求助内容:
应助结果提醒方式:
