摘要
【目的】降低烤烟生长后期植烟土壤的氮素供应对提高烤烟烟叶质量非常重要,而微生物同化作用在调控土壤有效氮含量过程中起着重要作用,且受添加有机碳源质量和数量的影响。因此,我们研究不同有机碳源降低土壤矿质氮的效果,以及碳添加量与矿质氮降低量间的定量关系。【方法】供试土壤采自贵州玉米烟草轮作土壤,属于黄壤土。供试有机碳源有5种,分别为小麦秸秆、玉米秸秆、芦苇秸秆、木屑和葡萄糖。有机碳源添加量均设置4个纯碳水平,分别为0、2.0、5.0和10.0 g/kg,在室内培养开始前,每个处理添加N 0.2 g/kg(NH_(4)NO3),培养周期为30天,期间共采集培养瓶内气体样品8次,测定CO_(2)排放量和N_(2)O排放量,采集土壤样品5次,分析了土壤矿质氮、有机碳和微生物量碳含量。【结果】与未添加碳源处理相比,添加碳源处理在培养结束时显著提高了土壤呼吸速率,CO_(2)累积排放量增加幅度为64.8%~729.3%;并显著增加了微生物量碳含量,且微生物量碳含量与碳添加量之间呈极显著正相关。培养结束时,添加碳源处理显著降低了矿质氮含量,降低幅度分别为20.7%~55.9%(玉米秸秆)、24.4%~99.8%(小麦秸秆)、21.4%~99.7%(芦苇秸秆)、31.4%~99.9%(木屑)和44.3%~84.8%(葡萄糖);且矿质氮降低量与碳添加量之间呈极显著正相关关系,1 g有机碳降低矿质氮的量为玉米秸秆11.4 mg、小麦秸秆20.8 mg、芦苇秸秆20.8 mg、木屑20.5 mg和葡萄糖16.1 mg。当碳添加量≤5.0 g/kg时,有机碳源的C/N值与培养结束时的矿质氮降低量之间呈极显著正相关(P<0.01)。添加秸秆类碳源可降低N_(2)O排放量,比未添加碳源处理降低78.7%~96.5%,而添加葡萄糖可显著增加N_(2)O排放量,比未添加碳源处理增加153.6%~298.6%。【结论】有机碳源的C/N值显著影响着其降低矿质氮含量的潜力,在一定添加范围内,向植烟土壤中添加有机碳源,矿质氮的降低
【Objectives】Reducing soil nitrogen supply at the later growth stage of flue-cured tobacco is very important to improve the quality of its leaves.Microbial immobilization plays a vital role in regulating the available N content in the soil and is affected by the quality and quantity of organic carbon supply.Therefore,this study explores the effects of different organic carbon sources in reducing soil mineral N.【Methods】We used the laboratory incubation method to test the yellow soil collected from the maize-tobacco rotation field in Guizhou Province.The five organic carbon sources selected were maize straw,wheat straw,reed straw,sawdust,and glucose.Each organic carbon source was added at four levels of pure carbon(C)0,2.0,5.0,and 10.0 g/kg.Before incubation,NH_(4)NO_(3)was added to each treatment at N 0.2 g/kg to simulate the mineral nitrogen in the soil at the late growth stage of flue-cured tobacco.Gas samples were collected to monitor CO_(2)and N_(2)O emissions on the 1,3,5,7,9,14,21,and 30 days of incubation.Soil samples were collected five times to determine mineral N,organic carbon,and microbial biomass carbon contents.【Results】Compared with the no carbon source treatment,the addition of carbon significantly improved the soil respiration rate.It increased the cumulative CO_(2)emission by 64.8%to 729.3%,and the microbial biomass carbon content significantly was increased.There was a significant positive correlation between the microbial biomass carbon content and the amount of carbon added to the soil.Mineral N content was(P<0.05)reduced by adding carbon sources.The reduction was 20.7%-55.9%in maize straw,24.4%-99.8%in wheat straw,21.4%-99.7%in reed straw,31.4%-99.9%in sawdust,and 44.3%-84.8%in glucose at the end of the incubation period.This corresponded to reducing mineral N per gram of organic carbon by 11.4 mg in maize straw,20.8 mg in wheat straw,20.8 mg in reed straw,20.5 mg in sawdust,and 16.1 mg in glucose.When carbon addition was less than or equal to 5.0 g/kg,the total reduction of miner
作者
李青山
王德权
杜传印
王大海
管恩森
王慎强
LI Qing-shan;WANG De-quan;DU Chuan-yin;WANG Da-hai;GUAN En-sen;WANG Shen-qiang(School of Environments and Resource,Anqing Normal University,Anqing,Anhui 246133,China;Nanjing Institute of Soil Science,Chinese Academy of Sciences,State Key Laboratory of Soil and Sustainable Agriculture,Nanjing,Jiangsu 210008,China;Shandong Weifang Tobacco Co.,Ltd.,Weifang,Shandong 261205,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2021年第6期1091-1103,共13页
Journal of Plant Nutrition and Fertilizers
基金
中国烟草总公司贵州省公司项目(201506)
山东潍坊烟草有限公司科技项目(2019-44)。
关键词
碳源类型
添加量
植烟土壤
氮素转化
N_(2)O
carbon source type
additive amount
tobacco-planting soil
nitrogen transformation
N_(2)O
