淹水深度对稻草还田土壤氧化还原状况的影响  

Effects of flooding depth on soil redox character of rice straw returning system

作　　者：宋春彦 张艳科 李一平 王昆昆 丛日环[1] 鲁剑巍[1] SONG Chun-yan;ZHANG Yan-ke;LI Yi-ping;WANG Kun-kun;CONG Ri-huan;LU Jian-wei(College of Resources and Environment,Huazhong Agricultural University/Key Laboratory of Arable Land Conservation Middle and Lower Reaches of Yangtze River,Ministry of Agriculture and Rural Affairs/Microelement Research Center,Huazhong Agricultural University,Wuhan Hubei 430070)

机构地区：[1]华中农业大学资源与环境学院/农业农村部长江中下游耕地保育重点实验室/华中农业大学微量元素研究中心,湖北武汉430070

出　　处：《中国土壤与肥料》2025年第3期11-16,共6页Soil and Fertilizer Sciences in China

基　　金：国家重点研发计划项目(2023YFD1901100)。

摘　　要：淹水条件下稻草还田影响稻田土壤氧化还原状况,进而影响下季水稻的生长,而不同淹水深度对土壤氧化还原状况影响程度及动态变化特征尚不明确。采用土柱培养模拟田间稻草全量还田,设置6个淹水深度处理,即淹水0(土壤浸润)、1、2、4、6和8 cm,测定培养28 d内土壤pH、电导率(EC)、氧化还原电位(Eh)、还原性物质总量、活性还原物质、Fe^(2+)和Mn^(2+)含量的动态变化,旨在为秸秆还田下稻田灌溉管理提出科学依据。结果表明,土壤Eh与淹水深度呈负相关,与土壤浸润处理相比,淹水1~8 cm时Eh降低65.4%~86.4%,而淹水深度对pH值和EC的影响不大(除浸润淹水时EC显著低于各淹水处理外)。各测定指标随还田培养天数的增加呈现动态变化:其中土壤pH值在培养7 d内呈上升趋势,培养14 d后不断下降至28 d时降至最低;而EC值随着培养时间的增加不断上升,以淹水4 cm时上升幅度最大(上升65.3%);土壤Eh随着培养时间的推移而不断下降,表明还原性不断增强,在7~14 d降幅最大(下降40%以上)。土壤还原性物质量与淹水深度整体呈负相关,淹水4~8 cm时土壤还原物质总量、活性还原物质及Fe^(2+)含量显著低于淹水1~2 cm,降幅分别为31.1%~49.5%、14.2%~54.1%、26.3%~37.3%。土壤浸润处理的各还原性物质随培养天数的增加逐渐上升,而淹水1~8 cm处理则在培养14 d内先上升随后下降。研究表明,稻草还田前期,淹水深度维持在4~6 cm可有效缓解还原性物质积累。Straw returning has an effect on the rice soil redox character and the growth of crop in the next season under different flooding depths,while the influence degree and dynamic change characteristics are still unclear.The total amount of straw returning was simulated by the soil column culture experiment,and six depths treatments were set up,including 0(infiltration),1,2,4,6 and 8 cm.The dynamic changes of soil pH,conductivity(EC),redox potential(Eh),total reducing material,active reducing material,Fe^(2+)and Mn^(2+)contents during 28 days of cultivation were measured,aiming to provide a scientific basis for irrigation management of rice fields under straw returning.The results showed that soil Eh was negatively correlated with flooding depth,and decreased by 65.4%-86.4%when flooded at 1-8 cm,compared with soil infiltration treatment,while flooding depth had little effect on pH value and EC(except that the EC was significantly lower than that of each flooding treatment).The indexes showed dynamic changes with the increase of the incubation days.The soil pH value showed an upward trend within 7 days of incubation,and continued to decrease after 14 days of incubation until reaching its lowest point at 28 days.The EC value was increased with the increase of incubation time,and the largest increase was 65.3%when the water was flooded at 4 cm.Soil Eh was decreased with the incubation time,indicating that the reducibility was increasing,with the largest decrease(more than 40%)at 7-14 days.The total amount of soil reducing material,active reducing material and Fe^(2+)content of flooding 1-2 cm treatments were significantly lower than those of flooding 4-8 cm treatments,and the decreases were 31.1%-49.5%,14.2%-54.1%and 26.3%-37.3%,respectively.The reducing compounds in the soil infiltration treatment increased gradually with the increase of incubation days,while the flooding 1-8 cm treatments increased and then decreased after 14 days of incubation.The results showed that maintaining the flooding depth at 4-6 cm in the ea

关 键 词：稻草还田 淹水深度 动态变化 氧化还原电位 还原性物质 

分 类 号：S511[农业科学—作物学]