[en] This study investigated the effects of different straw return practices-no-tillage with straw mulching (SM), shallow tillage with straw incorporation (SS), and deep tillage with straw incorporation (DS)-on the content and structural characteristics of soil water-soluble organic carbon (WSOC) under a maize-soybean rotation in the black soil region in the Northeast of China. Compared with SM, SS and DS increased WSOC content by 39.0% and 28.8% in the 0~20 cm layer (p < 0.05), and by 28.4% and 8.5% in the 20-40 cm layer, respectively. Deep tillage combined with straw return reduced the WSOC/SOC ratio. The DS treatment exhibited the highest levels under maize straw incorporation, while SM treatment showed the highest levels under soybean straw incorporation. Spectral indices in both maize and soybean seasons-including the fluorescence index (FI, ranging from 1.53 to 1.57 in the maize season and from 1.53 to 1.67 in the soybean season), biological index (BIX, ranging from 0.84 to 1.79 in the maize season and from 0.61 to 0.74 in the soybean season), and humification index (HIX, ranging from 0.51 to 0.79 in the maize season and from 0.84 to 0.97 in the soybean season)-collectively indicated that WSOC predominantly consisted of microbially processed organic matter with a low degree of humification. PARAFAC modeling resolved two fluorescent components in maize season: C1 (humic acid-like substances, accounting for 34.8-54.9%) and C2 (Tryptophan-like substance, accounting for 45.1-65.2%), and two components in the soybean season: C1 (humic-like substances, 51.0-53.7%), and C2 (Fulvic acid-like substance 46.3-49.0%). Overall, deep straw return promotes soil humification but increases the structural complexity of WSOC. This systematic investigation provides mechanistic insights into how straw return practices regulate the quantity and quality of labile carbon pools in agricultural ecosystems over time.
Disciplines :
Agriculture & agronomy
Author, co-author :
Kuang, Enjun ; Heilongjiang Academy of Black Soil Conservation and Utilization, Key Laboratory of Soil Environment and Plant Nutrition of Heilongjiang Province, Harbin 150086, China
Liu, Lin; Heilongjiang Academy of Black Soil Conservation and Utilization, Key Laboratory of Soil Environment and Plant Nutrition of Heilongjiang Province, Harbin 150086, China ; College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China
Wang, Zixuan; Heilongjiang Academy of Black Soil Conservation and Utilization, Key Laboratory of Soil Environment and Plant Nutrition of Heilongjiang Province, Harbin 150086, China ; College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China
Zhang, Jiuming; Heilongjiang Academy of Black Soil Conservation and Utilization, Key Laboratory of Soil Environment and Plant Nutrition of Heilongjiang Province, Harbin 150086, China
Zhu, Yingxue; Heilongjiang Academy of Black Soil Conservation and Utilization, Key Laboratory of Soil Environment and Plant Nutrition of Heilongjiang Province, Harbin 150086, China
Zhu, Di; Heilongjiang Academy of Black Soil Conservation and Utilization, Key Laboratory of Soil Environment and Plant Nutrition of Heilongjiang Province, Harbin 150086, China
Colinet, Gilles ; Université de Liège - ULiège > TERRA Research Centre > Echanges Eau - Sol - Plantes
Guo, Baofeng; Central Reserve Grain Nenjiang Direct Warehouse Co., Ltd., 93 Branch, Nenjiang 161441, China
Sun, Lei; Heilongjiang Academy of Black Soil Conservation and Utilization, Key Laboratory of Soil Environment and Plant Nutrition of Heilongjiang Province, Harbin 150086, China
Language :
English
Title :
Enhancing Soil Water-Soluble Carbon Stability Structure Through Straw Return in Maize-Soybean Rotation in Mollisols.
Project of Soybean Industry System Heilongjiang Ecological Environment Protection Research Project Agricultural Science and Technology Innovation Leap Project Provincial Research Business Expenses Natural Science Foundation of Heilongjiang Province Project
Funders :
NSCF - National Natural Science Foundation of China
