Effects of long-term straw application and groundwater management on acidification of paddy soils in subtropical China: Insight from a 35-year field experiment

作者：Yue Dong, Shuai Liu, Yiting Hu, Jan Mulder, Samuel Adingo, Yafeng Nie, Lichu Yin, Yan Ma, Xinhua Peng · 发表于：Agricultural Water Management · 年份：2025 · DOI：10.1016/j.agwat.2025.109337 · 被引用次数：7 · 研究领域：Soil and Unsaturated Flow、Soil, Finite Element Methods、Climate change and permafrost

As an important renewable agricultural by-product, straw application has been recommended worldwide as an effective and economical agricultural management practice. However, there remain potential risks associated with straw application, especially straw-induced soil acidification in croplands. Until now, the effect of straw application on soil acidification is inconclusive, and there is still a lack of knowledge concerning the combined impacts of groundwater management and straw application on soil acidification. A 35-year field experiment was conducted in subtropical China to assess the effects of long-term straw application and groundwater management on the acidification of paddy soils. The experiment was set up with a two-factor design of groundwater table depth (shallow groundwater table (SGT): 20 cm depth; deep groundwater table (DGT): 80 cm depth) and straw application rate (CK: chemical fertilizers with no straw application; OM1: straw substituting with one-third of N fertilizers, conventional application; OM2: straw substituting with two-thirds of N fertilizers.). After 35 years of treatment, soil pH in the 0–10 and 10–20 cm layers decreased by 0.81–1.30 units under all six treatments, while soil pH in the 20–40 cm layer decreased only under the SGT treatment. In the upper two layers, due to the high initial soil pH (6.16) and low base cations in the applied straw, straw application promoted the dissociation of straw-derived weak acids, the leaching of dissolved carb...