欢迎访问PEDOSPHERE网站！

Pedosphere 35(6): 1054--1064, 2025
ISSN 1002-0160/CN 32-1315/P
©2025 Soil Science Society of China
Published by Elsevier B.V. and Science Press

Efficiency-enhancing methods for predicting nitrogen mineralization characteristics in paddy soils using soil properties and rapid soil extractions

Yujuan LIU^1,2, Yuqi CHEN^1,2, Xiuyun LIU^1,2, Siyuan CAI¹, Jiahui YUAN³, Lingying XU¹, Yu WANG¹, Xu ZHAO^1,4

, Xiaoyuan YAN^1,4

¹ State Key Laboratory of Soil and Sustainable Agriculture, Changshu National Agro-Ecosystem Observation and Research Station, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 211135 (China);
² University of Chinese Academy of Sciences, Beijing 100049 (China);
³ Heilongjiang Academy of Black Soils Conservation and Utilization, Key Laboratory of Black Soil Protection and Utilization, Ministry of Agriculture and Rural Affairs, Heilongjiang Academy of Agricultural Sciences, Harbin 150086 (China);
⁴ University of Chinese Academy of Sciences, Nanjing, Nanjing 211135 (China)

ABSTRACT

Soil mineralized nitrogen (N) is a vital component of soil N supply capacity and an important N source for rice growth. Unveiling N mineralization (Nm) process characteristics and developing a simple and effective approach to evaluate soil Nm are imperative to guide N fertilizer application and enhance its efficiency in various paddy soils with different physicochemical properties. Soil properties are important driving factors contributing to soil Nm differences and must be considered to achieve effective N management. Nevertheless, discrepancies in Nm capacity and other key influencing factors remain uncertain. To address this knowledge gap, this study collected 52 paddy soil samples from Taihu Lake Basin, China, which possess vastly different physicochemical properties. The samples were subjected to a 112-d submerged anaerobic incubation experiment at a constant temperature to obtain the soil Nm characteristics. Reaction kinetics models, including one-pool exponential model, two-pool exponential model, and effective cumulative temperature model, were employed to compare characteristic differences between Nm potential (Nmp) and short-term accumulated mineralized N (Amn) processes in relation to soil physicochemical properties. Based on these relationships, simplified Nmp prediction methods for paddy soils were established. The results revealed that the Nmp values were 145.18, 88.64, and 21.03 mg kg^-1 in paddy soils with pH < 6.50, 6.50 ≤ pH ≤ 7.50, and pH > 7.50, respectively. Significantly, short-term Amn at day 14 showed a good correlation (P < 0.01) with Nmp (R² = 0.94), indicating that the prevailing short-term incubation experiment is an acceptable marker for Nmp. Moreover, Nmp correlated well with the ultraviolet absorbance value at 260 nm based on NaHCO₃ extraction (Na260), further streamlining the Nmp estimation method. The incorporation of easily obtainable soil properties, including pH, total N (TN), and the ratio of total organic carbon to TN (C/N), alongside Na260 for Nmp evaluation allowed the multiple regression model, Nmp = 58.62 × TN - 23.18 × pH + 13.08 × C/N + 86.96 × Na260, to achieve a high prediction accuracy (R² = 0.95). The reliability of this prediction was further validated with published data of paddy soils in the same region and other rice regions, demonstrating the regional applicability and prospects of this model. This study underscored the roles of soil properties in Nm characteristics and mechanisms and established a site-specific prediction model based on rapid extractions and edaphic properties of paddy soils, paving the way for developing rapid and precise Nm prediction models.

Citation: Liu Y J, Chen Y Q, Liu X Y, Cai S Y, Yuan J H, Xu L Y, Wang Y, Zhao X, Yan X Y. 2025. Efficiency-enhancing methods for predicting nitrogen mineralization characteristics in paddy soils using soil properties and rapid soil extractions. Pedosphere. 35(6): 1054-1064.

View Full Text