论文部分内容阅读
【目的】N2O是重要的温室气体,其增温潜势是CO2的298倍,而且破坏臭氧层。森林生态系统是陆地生态系统的重要组成部分,占全球陆地面积的33%,森林土壤N2O排放对全球气候变化有重大的影响。山核桃(Carya cathayensis)是非常重要的经济林,是山核桃主产区农民的主要经济来源。近年来,农民采取施用无机肥和有机肥等措施来提高山核桃产量,但施肥对山核桃林地土壤N2O排放的影响尚不清楚,本文以不施肥作为对照(CK),研究单施有机肥(Organic fertilizer,OF)、单施化肥(Inorgnaic fertilizer,IF)、有机无机肥配施(Organic fertilizer and Inorgnaic fertilizer,OIF)对山核桃林地土壤N2O气体排放的影响。【方法】利用静态箱-气相色谱法对山核桃林地土壤N2O排放通量进行了为期1年的测定。采样箱为组合式,即由底座、顶箱组成,均用PVC板做成,面积为30cm×30 cm,高度为30 cm。气体样品采集频率基本为每月1次,采集气体时,将采集箱插入底座凹槽(凹槽内径和深度均为5 cm)中,用蒸馏水密封,分别于关箱后0、10、20、30 min采集,用注射器抽样60 mL置于气袋,带回实验室用岛津GC-2014气相色谱仪进行测定,检测器为电子捕获检测器(ECD),检测器温度为250℃。【结果】山核桃林地不同施肥土壤N2O排放通量均呈现明显的季节性变化,以夏季最高、冬季最低。土壤N2O的排放通量在N-0.021~0.161 mg/(m2·h)之间变化,不同处理土壤N2O年累积排放量依次为单施有机肥>单施化肥>有机无机肥配施>对照,对应值分别为N 2.17、2.01、1.94和0.94 kg/(hm2·a)。与对照相比,施肥处理显著增加N2O的排放(P<0.05),但是各施肥处理N2O排放量之间的差异不显著。单施有机肥和有机无机肥配施处理土壤N2O排放通量与土壤水溶性有机碳含量和微生物量碳呈显著相关关系(P<0.05),而单施化肥和对照则无显著相关性。土壤N2O排放通量与地下5 cm处土壤温度均显著相关(P<0.05),而土壤N2O排放与土壤含水量间没有显著相关性。【结论】施肥显著促进了山核桃林地土壤N2O排放,不同施肥处理之间山核桃林地土壤N2O排放无显著差异。添加有机肥引起土壤水溶性有机碳和微生物碳的增加可能是有机肥增加山核桃林地土壤N2O排放速率的主要原因之一。
【Objective】 N2O is an important greenhouse gas with a warming potential of 298 times that of CO2 and destroys the ozone layer. Forest ecosystems are an important part of terrestrial ecosystems, accounting for 33% of the global land area. N2O emissions from forest soils have a significant impact on global climate change. Carya cathayensis is a very important economic forest and is the main source of income for peasants in the main pecan husks. In recent years, peasants have adopted such measures as the application of inorganic and organic fertilizers to increase the yield of pecan. However, the effect of fertilization on the N2O emission of peatland soil is not clear. In this paper, CK (CK) Effects of Organic Fertilizer (OFOF), Inorganic Fertilizer (IF) and Organic Fertilizer and Inorganic Fertilizer (OIF) on N2O Emissions from Hickory Cultivars Soil. 【Method】 The N 2 O fluxes in the soil of Hickory nutmeg were determined by static box-gas chromatography for one year. The sampling box is a combination of the base and the top box, all made of PVC plate, with an area of 30 cm × 30 cm and a height of 30 cm. Gas sampling frequency is basically once a month, the gas collection, the collection box into the base groove (groove diameter and depth are 5 cm), sealed with distilled water, respectively, after the closed box 0,10,20, 30 min collection, with a syringe sampling 60 mL placed in air bags, back to the laboratory Shimadzu GC-2014 gas chromatograph for detection, the detector for the electron capture detector (ECD), the detector temperature is 250 ℃. 【Result】 The results showed that the N2O emission flux of different fertilization soils in Hickory Nalpine had obvious seasonal changes, the highest in summer and the lowest in winter. The N2O emission flux of soil varied from N-0.021 to 0.161 mg / (m2 · h). The cumulative N2O emissions of different treatments were followed by single application of organic fertilizer> single application of chemical fertilizer> organic-inorganic fertilizer> The corresponding values were N 2.17, 2.01, 1.94 and 0.94 kg / (hm2 · a), respectively. Compared with the control, fertilization significantly increased N2O emissions (P <0.05), but there was no significant difference between the N2O emissions of different fertilization treatments. There was a significant correlation between soil N2O flux and soil organic carbon (SOC) and microbial biomass C (P <0.05) with application of organic manure and organic manure. However, no significant correlation was found between chemical fertilization and control. Soil N2O flux was significantly correlated with soil temperature at 5 cm below ground (P <0.05), while there was no significant correlation between soil N2O emission and soil water content. 【Conclusion】 N fertilization significantly promoted the N2O emission in the soil of Hickory Nuts. There was no significant difference in soil N2O emission from the Hickory Hickory soil between different fertilization treatments. The increase of water-soluble organic carbon and microbial carbon in soil caused by adding organic fertilizers may be one of the main reasons that organic manure increases the N2O emission rate in soil of peatland forest.