添加外源有机物对长期不同施肥处理水稻土有机碳矿化的影响  

Effects of external organic matter input on the mineralization of organic carbon in paddy soils with long-term fertilizations

作　　者：冷雪梅 钱九盛 张旭辉[1] 谢文逸 刘晓雨[1] 郑聚锋[1] 郭世伟 李恋卿[1] 潘根兴[1] LENG Xuemei;QIAN Jiusheng;ZHANG Xuhui;XIE Wenyi;LIU Xiaoyu;ZHENG Jufeng;GUO Shiwei;LI Lianqing;PAN Genxing(Institute of Resource,Ecosystem and Environment of Agriculture,Nanjing Agricultural University,Nanjing 210095,China)

机构地区：[1]南京农业大学农业资源与生态环境研究所,江苏南京210095

出　　处：《南京农业大学学报》2022年第1期103-112,共10页Journal of Nanjing Agricultural University

基　　金：国家自然科学基金项目(41471193)。

摘　　要：[目的]通过研究添加外源有机物对不同施肥条件下水稻土有机碳矿化及形态的影响,探究不同施肥措施对水稻土有机碳稳定性的影响,为水稻土的合理碳管理施肥提供参考。[方法]以江苏溧阳白土(4年定位试验)和如皋高砂土(11年定位试验)2种典型水稻土为研究对象,各选取4个不同肥料处理的耕层(0~15 cm)土样,各处理分别为不施肥(CK)、农民习惯施肥(N 300 kg·hm^(-2),FFP)、优化施肥(N 240 kg·hm^(-2),OPT)和牛粪替氮(OPT施肥基础上牛粪替代20%化学氮肥,CMSN),采用室内培养法(培养周期60 d)研究添加外源有机物(玉米秸秆)对土壤CO_(2)排放动态、总有机碳、活性碳库等含量及激发效应的影响。[结果]添加玉米秸秆可显著提高水稻土土壤有机碳的矿化速率,白土FFP处理土壤CO_(2)排放量较CK降低8.75%,高砂土OPT和CMSN处理土壤CO_(2)排放量较CK分别提高30.38%和13.38%。培养初期,除高砂土的CMSN处理产生负激发效应外,其他土壤均表现出正激发效应,其相对激发效应随培养时间逐渐降低。添加玉米秸秆可显著提高各处理土壤总有机碳含量,白土的FFP和OPT处理及高砂土的OPT和CMSN处理提高效果显著。相比于未施肥土壤,白土CMSN处理和高砂土FFP处理显著提高可溶性有机碳含量;白土和高砂土的FFP和OPT处理显著提高微生物量碳含量;施肥可以提高白土颗粒态有机碳含量,CMSN处理提高效果最显著,高砂土只有OPT处理提高了颗粒态有机碳含量;2种水稻土的各个施肥处理对易氧化态有机碳含量没有显著影响。[结论]添加玉米秸秆可以提高所有处理土壤的有机碳矿化速率、土壤总有机碳和活性碳库组分含量,其中CMSN处理在2种土壤中均产生较低的正激发效应或负激发效应,更有利于土壤有机碳固存。[Objectives]The objective of this study was to investigate the effect of external organic matter input on mineralization and forms of organic carbon in paddy soil under different fertilization conditions.This study was to explore the effects of different fertilization measures on the stability of organic carbon in paddy soil,and to provide reference for carbon management and fertilization of paddy soil.[Methods]Soil samples of albic paddy soil and sandy loam paddy soil under four fertilization managements were collected from Liyang(4-year experiment)and Rugao(11-year experiment)of Jiangsu Province respectively.Four topsoil samples(0-15 cm)treated with different fertilizers were selected for each paddy soil.The fertilization treatments included:no fertilization(CK),local farmer’s fertilizer practice(N 300 kg·hm^(-2),FFP),optimal fertilization(N 240 kg·hm^(-2),OPT)and the N rate substituted by 20%N with cattle manure based on OPT treatment(CMSN).A 60-day incubation experiment by adding external organic matter(maize straw)was conducted to measure CO_(2) fluxes,total and active organic carbon content,and to calculate the priming effect.[Results]Adding maize straw could significantly increase the mineralization rate of soil organic carbon in paddy soil.The cumulative CO_(2) emission in FFP was 8.75%lower than that in CK in albic paddy soil.The cumulative CO_(2) emissions in OPT and CMSN were 30.38%and 13.38%higher than those in CK in sandy loam paddy soil,respectively.At the beginning of incubation,except the negative priming effect in CMSN in sandy loam paddy soil,all the other soils showed positive priming effect and a trend of decreasing priming effect gradually.By the end of incubation experiment,total soil organic carbon increased under the addition of maize straw.The total soil organic carbon significantly improved in FFP and OPT of albic paddy soil,and in OPT and CMSN of sandy loam paddy soil.Compared with CK,CMSN in albic paddy soil and FFP in sandy loam paddy soil significantly increased the content of so

关 键 词：水稻土 外源有机物添加 有机碳矿化 激发效应 有机碳稳定性 

分 类 号：S153.6[农业科学—土壤学]