Yan Sun, Bingbing Wu, Bowei Ren
Responses to BFA differed between the two soils with different textures and among application rates and were most pronounced during the early incubation period. In sandy loam, 2 g·kg-1 BFA increased ammonium nitrogen and nitrate nitrogen by 68% and 53%, respectively, on day 15 relative to the control. In loamy sand, 1 g·kg-1 BFA increased nitrate nitrogen by 92% on day 15 and ammonium nitrogen by 70% on day 30. Sequencing analysis of soil samples collected on day 45 revealed distinct microbial community responses to 2 g·kg-1 BFA in sandy loam and 1 g·kg-1 BFA in loamy sand.
BACKGROUND: Sodic saline-alkali soils restrict agricultural productivity by limiting nutrient availability and disrupting microbial communities, yet their responses to biochemical fulvic acid (BFA) across sodic saline-alkali soils with different textures remain unclear.
METHODS: A 45-day controlled incubation experiment was conducted using sandy loam and loamy sand amended with BFA at 0, 1, 2, 4, and 8 g kg-2.
RESULTS: Responses to BFA differed between the two soils with different textures and among application rates and were most pronounced during the early incubation period. In sandy loam, 2 g·kg-1 BFA increased ammonium nitrogen and nitrate nitrogen by 68% and 53%, respectively, on day 15 relative to the control. In loamy sand, 1 g·kg-1 BFA increased nitrate nitrogen by 92% on day 15 and ammonium nitrogen by 70% on day 30. Sequencing analysis of soil samples collected on day 45 revealed distinct microbial community responses to 2 g·kg-1 BFA in sandy loam and 1 g·kg-1 BFA in loamy sand.
RESULTS: Within the conditions of this trial, the optimum application rates were 2 g·kg-1 in sandy loam and 1 g·kg-1 in loamy sand, corresponding to the most remarkable responses.