Response of N_2O Emissions of Farmland Ecosystem on Temperature Rising

[Objective] The aim was to study on response of N2O emissions of farm- land ecosystem on temperature rising. [Methed] In farmland ecosystem in Huaibei City in Anhui Province, N2O emission by twelve varieties of crop on temperature was researched with DeNitrification-DeComposition （NDC）. [Result] Response of dry- land crop on temperature rising can be divided into three categories, as follows： The first category, N2O emission of crop changed little during the temperature increasing, for example, from 0 to 3 %;, the emissions by potatoes, cotton, maize and rapeseed increased little and decreased little when temperature changed from 1.5 to 3 ℃. Crops of the second category declined with temperature increasing in N2O emission, for example, N2O emission decreased by 8.1% with temperature increasing from 0 to 3 ℃, including sugar cane, tobacco, wheat, soybean and pea. In third category, N2O emission of crop grew with temperature increasing, for example, the emission of rice, vegetables and fruit trees increased by 22.8% when the temperature grew from 0 to 3 ℃. [Conclusion] The research indicated that N2O emission in ecosystem of drv farmland increased little with temoerature risina.

静态箱/气相色谱法监测农田温室气体排放研究

农田温室气体减排是减缓全球变暖的一个重要举措,因此对气体排放通量的准确观测至关重要。静态箱/气相色谱法是测量土壤温室气体较为常用的方法,该研究通过比较气体样品在不同存储装置内存储不同时间对样品中CO、CH和NO浓度的影响,根据测试结果对气体样品采集和存储过程进行优化,确保样品数据的准确性。室内测试结果显示,若采样后气体样品在当天内测定,CO、CH和NO浓度在气袋和注射器中变化均较小,随着存储时间的延长气袋中样品浓度的稳定性更高;另外,气体浓度变化大小与存储装置内外气体的浓度差有关,表现为样品浓度较高的气体随着存储时间的延长变化也较大。利用该研究中优化的气体浓度分析流程和方法,开展农田小麦/玉米轮作体系有机无机肥配施下温室气体排放的观测研究,获得不同比例有机肥配施化肥处理下的NO排放量和作物产量,并得出该区有机肥氮替代75%化肥氮是保证作物产量和减少农田NO排放的最佳比例。