Dissolved inorganic nitrogen (DIN) adsorbed onto soil colloids plays an important role in soil N leaching, but previous studies have not clearly defined the mechanisms of this process in paddy soils under organic fertilization. In this study, we investigated how ongoing fertilization can change soil DIN leaching via affects on soil-surface electrochemical properties and physical properties, and the main influences of soil properties on DIN leaching were characterized. Five fertilization regimes applied during a 5-year field experiment were employed to study this mechanism, i.e., no fertilizer, chemical fertilizer, chemical fertilizer plus hog manure, hog manure, and chemical fertilizer plus oil cake. Increasing levels of applied manure decreased DIN leaching from the soil profile, especially for NH₄⁺, the main form of DIN in the leachate and soil. Compared to chemical fertilizer, organic fertilization changed the surface electrochemical and physical properties more effectively with regards to decreased soil bulk density (9.84–20.49 %, P < 0.05) and specific surface area (26.38–44.88 %, P < 0.05), as well as enhanced water-holding capacity (19.05–42.86 %, P < 0.05) and the number and density of soil-surface charges (7.97.55–98.44 %, P < 0.05). Furthermore, organic fertilization significantly increased the NH₄⁺ adsorbed by soil. Structural equation modeling showed that soil-surface electrochemical properties had the greatest impact (β = –0.88, P < 0.05) on the NH₄⁺ content of the leachate when compared with the soil NH₄⁺ adsorption capacity and physical properties. The increase in the soil-surface charge, surface charge density, surface potential, and surface electric field strength under organic fertilization increased soil NH₄⁺ retention in soil (P < 0.001), and thus, these changes decreased the risk of NH₄⁺ leaching. Our results suggest that continuous substantial organic fertilization may mainly decrease early DIN leaching from cultivated paddy soils in the Dongting Lake area by altering soil-surface electrochemical properties, where soil-surface electrochemical properties can be set as an internal factor to predict soil ion migration in agriculture systems, such as the Dongting Lake area or other similar regions.

吸附到土壤胶体上的溶解性无机氮（DIN）在土壤N淋溶中起着重要作用，但是以前的研究尚未明确定义有机肥作用下稻田土壤中该过程的机理。在这项研究中，我们研究了持续施肥如何通过对土壤表面电化学性质和物理性质的影响来改变土壤DIN淋溶，并表征了土壤性质对DIN淋溶的主要影响。在五年的田间试验中采用了五种施肥方案来研究这种机理，即不施肥，化肥，化肥加猪粪，猪粪，化肥加油饼。施肥水平的提高减少了土壤中DIN的淋失，特别是对于NH ₄ ⁺，是渗滤液和土壤中DIN的主要形式。与化学肥料相比，有机肥在降低土壤容重（9.84–20.49％，P <0.05）和比表面积（26.38–44.88％，P <0.05）方面更有效地改变了表面电化学和物理性质。增强了持水能力（19.05–42.86％，P <0.05）和土壤表层电荷的数量和密度（7.97.55–98.44％，P <0.05）。此外，有机施肥显着增加了土壤吸附的NH ₄ ⁺。结构方程模型表明，土壤表面电化学性质对NH有最大的影响（β= –0.88，P <0.05）与土壤NH ₄ ^+的吸附能力和物理性质相比，渗滤液中₄ ^+的含量。有机肥下土壤表面电荷，表面电荷密度，表面电势和表面电场强度的增加增加了土壤中的NH ₄ ⁺保留量（P <0.001），因此，这些变化降低了NH ₄ ⁺的风险。浸出。我们的研究结果表明，通过改变土壤表面的电化学特性，连续大量的有机肥可能主要通过减少洞庭湖地区稻田土壤中的早期DIN淋溶，而土壤表面的电化学特性可以作为预测土壤离子迁移的内部因素。农业系统，例如洞庭湖地区或其他类似地区。