为了掌握土壤氧化亚氮排放对库尔勒香梨园造成的氮肥损失率,从而为香梨园氮肥的科学施用,提高氮素利用效率及改善果园生态环境提供理论依据和实践指导,以新疆维吾尔自治区库尔勒市树龄为6a的库尔勒香梨园为研究对象,采用静态箱-气相色谱法对香梨树整个生育期内香梨园土壤中氧化亚氮的排放通量及累积量进行了观测与分析.结果表明:(1)氧化亚氮的排放量在施肥后明显增大,其排放通量在施用基肥后第5天下午出现峰值(0.2498 g·hm-2h-1),其日累积量在施用基肥后第5天也出现峰值(4.216 g.hm-2d-1);(2)土壤温度会显著影响氧化亚氮的排放量,氧化亚氮的排放量在一天内表现出下午(16:00-20:00)＞中午(12:00-16:00)＞上午(8:00-12:00)＞夜间(20:00-8:00)的变化特征;(3)每月中旬对试验样地进行灌水处理后,由于干湿交替过于频繁,氧化亚氮的排放量明显增大;在不施肥的月份里,氧化亚氮的排放量呈现出月中＞月初＞月末的变化特征;(4)氧化亚氮的月累积量,在施肥后的4月和6月均较高,分别达到106.564和97.276 g·hm-2月-1;在香梨树的整个生育期内,氧化亚氮的累积总量达到了455.54 g·hm-2.%In order to understand nitrogen loss rate caused by soil nitrous oxide emission in korla fragrant pear orchard,and to provide theoretical basis and practical guidance for scientific application of nitrogen fertilizer,as well as for improvement of nitrogen utilization and ecological environment,taking the 6-year-old Korla fragrant pear as study objects in Korla of Xinjiang,the soil nitrous oxide emission flux and accumulative amount during the whole growth period of Korla fragrant pear by applying the static box-gas chromatography method.The results showed that:(1) The emissions of nitrous oxide was increased obviously after fertilization,the peak value of emission flux occurred in the aftemoon of the fifth day after applying basal fertilizer (0.2498 g.hm-2h-1),and the diurnal cumulative amount also occurred in the aftemoon of the fifth day after applying basal fertilizer (4.216 g.hm-2d-1).(2) The soil temperature had an significantly effect on the nitrous oxide emissions,and nitrous oxide emissions in one day presented the following characteristic:aftemoon (16:00-20:00) ＞ noon (12:00-16:00) ＞ morning (8:00-12:00) ＞ night (20:00-08:00).(3) After irrigating the test sample in the middle of each month,nitrous oxide emissions was increased obviously due to alternating wet and dry seasons too frequently;in the month without fertilizer,nitrous oxide emissions present the following characteristic:the middle of the month ＞ the beginning of the month ＞ the end of the month.(4) The accumulative amount of nitrous oxide were higher in April and June after fertilization,respectively reaching 106.564 and 97.276 g.hm-2.In the growth period of Korla fragrant pear,the amount of nitrous oxide accumulation reached 455.54 g.hm-2.
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