有机肥部分替代化肥对温室番茄土壤N2O排放的影响

Effect of Organic Partial Replacement of Inorganic Fertilizers on N2O Emission in Greenhouse Soil

【目的】在等氮量有机部分替代化肥条件下研究温室番茄土壤N2O排放特征,探讨影响温室土壤N2O排放的环境因素,为估算温室菜地系统N2O的排放清单及其减排潜力提供数据支撑和理论依据。【方法】以温室秋冬茬番茄为研究对象,设置不施肥(CK)、单施有机肥(MN)、单施化肥(CN)、有机肥部分替代化肥(CMN)4个处理,采用静态箱-气相色谱法,对番茄生育期内土壤N2O排放及土壤温度、含水量进行监测。【结果】在相同施氮量情况下,处理CMN(有机部分替代无机)的N2O排放总量为4.05 kg·hm^-2,相比处理CN(单施化肥)和MN(单施有机肥),土壤N2O排放总量降低了45.1%和33.2%;土壤N2O排放系数分别降低了50.0%和37.5%;排放强度降低了50.0%、42.1%。各处理土壤N2O排放通量峰值均出现在施肥灌水后第1天,排放主要集中在施肥灌溉后5 d内。温室番茄土壤N2O排放通量与0-5 cm地温呈显著或极显著线性相关关系;与土壤充水孔隙率(WFPS)呈显著或极显著的对数函数关系,且不同施肥处理下土壤N2O排放峰值出现在土壤充水孔隙率60%—80%范围内。【结论】温室番茄土壤N2O排放的消长关系表现在温湿度变化和氮肥投入类型等方面,合理的减排措施应综合考虑以上因素。有机部分替代化肥施肥模式是提高温室番茄产量,减少N2O排放排放强度、排放系数和排放总量,提高肥料利用率,实现化肥零增长的重要手段。

【Objective】Under the condition of replacing the inorganic fertilizer part with the same amount of nitrogen,the purpose of this study was to study the emission characteristics of greenhouse tomato soil N2O and to explore the environmental factors affecting N2O emissions,which could provide data support and theoretical basis for the N2O emission inventory of the greenhouse vegetable system and its emission reduction potential【.Method】Taking greenhouse autumn-winter tomato as the research object,the static-chamber method was used to monitor the soil N2O emission,soil temperature and soil water content during the growth period of tomato.The experiment was set 4 treatments,including non-fertilization(CK),single application of organic fertilizer(MN),single application of inorganic fertilizer(CN),and organic partial replacement of inorganic fertilizers(CMN).【Result】Under the same nitrogen application rate,the total N2O emission under CMN was 4.05 kg·hm^-2.Compared with CN and MN,the total N2O emission under CMN decreased by 45.1% and 33.2%,respectively;the emission factor of soil N2O was reduced by 50.0% and 37.5%,respectively;the emission intensity was reduced by 50.0% and 42.1%,respectively.The peak soil N2O of all treated appeared on the first day after fertilization and irrigation,and the discharge was mainly concentrated within 5 days after fertilization and irrigation.The N2O emission flux in greenhouse tomato soil showed significant or extremely significant correlation with the ground temperature of 0-5 cm soil,and showed a significant or extremely significant logarithm function relationship with soil water-filled porosity(WFPS).The peak of soil N2O emission under different fertilization treatments appeared in 60%~80% soil-filled porosity.【Conclusion】The relationship between the growth and decline of N2O emissions in greenhouse tomato soil was reflected in the changes of temperature and humidity and the type of nitrogen fertilizer input.Reasonable emission reduction measures should be considered based on the above factors.Partial replacement of inorganic fertilizers with organic fertilizers was an important means to increase greenhouse tomato production,to reduce N2O emissions intensity,factor and total N2O emissions increase fertilizer utilization,and to achieve zero growth of fertilizers.