摘要
为提高传统开顶式气室(Open-top chamber,OTC)在田间条件下原位模拟大气CO_2浓度升高对作物生长影响的适用性和精度,通过尺寸放大(长×宽×高=4.0 m×4.0 m×3.0 m)、形状调整(正四边形棱柱状)、新材料应用(塑钢PC结构)及内部CO_2浓度优化控制等措施对其进行了改进,并利用改进的OTC分别于2015—2016年在旱作春玉米农田原位模拟大气CO_2浓度升高的情形,通过对比玉米生育期内OTC内外CO_2浓度、温度和空气相对湿度,探讨了其模拟效果。结果表明:可控CO_2OTC内部CO_2浓度能够控制在预期值范围内,2015年控制误差范围为-17.2~0.2μmol·mol-1,2016年为-5.4~0.1μmol·mol-1,控制效果良好;可控CO_2OTC对室内气温产生了一定的影响,与气室外相比,在白天2015年平均增温0.8℃,差异显著(P<0.05),2016年平均增温0.4℃,差异不显著(P>0.05);可控CO_2OTC内部空气相对湿度与大田相比有所降低,2015年约降低2.4%,2016年降低了3.1%,差异均不显著(P>0.05)。研究表明,改进后的开顶式气室性能稳定,模拟精度高,能够较为准确地反映CO_2浓度升高后的旱作春玉米生长,可用于今后的大田模拟试验研究。
In order to improve the applicability and accuracy of Open-Top Chambers（OTCs）in simulating the effects of elevated CO2 on crop growth and yield under field conditions, the open-top area of the chamber was increased, the shape of the bottom was modified from octagonal to square, a new material was used for the chamber walls, and fans were installed in the chamber to increase air circulation. These improved OTCs were used for simulating elevated CO2 concentration in spring maize farmland in 2015 and 2016. The chamber measured 4.0m × 4.0 m × 3.0 m（length × width × height）and was equipped with an automated CO2 delivery system designed to maintain the CO2 concentration at 700 μmol·mol-1 in the chamber. During the maize growth period, CO2 concentration, air temperature, and relative humidity were measured automatically every 10 minutes both inside and outside the OTCs. The CO2 concentration, air temperature, and relative humidity inside the OTCs were compared to those under natural conditions, and the simulation performance was analyzed. The results demon-strated that the CO2 concentration could be well controlled by the improved OTC system. The deviation from the targeted CO2 concentration ranged from-17.2 μmol·mol-1 to 0.2 μmol·mol-1 in 2015 and from-5.4 μmol·mol-1to 0.1 μmol·mol-1 in 2016. The mean air temperature inside the OTCs was 0.8 ℃ higher than that of the natural air during daytime in 2015（P〈0.05）, and no significant difference in such was observed for 2016. There was no significant difference in relative humidity between inside and outside of the chambers（P〉0.05）. Our results indicated that the improved OTC has stable performance and high accuracy and can be used for future field simulation experiments.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2017年第6期1034-1043,共10页
Journal of Agro-Environment Science
基金
国家自然科学基金项目(31470523)
国家重点实验室开放基金项目(A314021402-1614)
西北农林科技大学科研专项(2013BSJJ119)~~
