摘要
【目的】明确CO2浓度升高与施氮对棉花光合作用、干物质积累以及产量的影响,为全面评价农田生态系统对其的响应提供依据。【方法】在大田开放系统中,利用半封闭开顶式气室,采用裂区设计的方法,设置主区为CO2浓度,副区为不同氮肥水平,在棉花进入盛花期每天12：00~15：00释放CO2气体,连续20 d,研究测定此状态下棉花倒四叶净光合速率、SPAD值、花后干物质积累量以及产量。【结果】CO2浓度增加0.5倍使棉花盛花期倒四叶光合速率在450 kg/hm2施氮量时增幅最大,达121.1%,在不施氮时增幅较小,为47.2%,在150和300 kg/hm2氮水平时反而减小;增加氮肥施入与CO2浓度增加0.5倍对叶绿素含量有明显的正向效应,但浓度倍增会使其降低;CO2浓度升高与增施氮肥对棉花花后干物质积累有正向效应;单铃重和籽棉产量CO2浓度升高处理均高于本底浓度处理,最大增加0.3 g和增产428.6 kg/hm2（P〈0.05）,增幅为6%和6.6%,且在0~300 kg/hm2施氮范围内单株结铃呈增加趋势,同时CO2浓度升高使衣分显著下降,但增加氮肥施入可使其改善。【结论】CO2浓度适当升高与在一定范围内增施氮肥可以提高棉花盛花期倒四叶叶绿素含量、促进光合速率提高,进而对棉花花后干物质积累产生正向效应,且同时使单株结铃呈增加趋势,并显著提高单铃重及籽棉产量;但高CO2浓度使叶绿素合成受阻,并使光合速率下降,同时降低衣分含量。
【Objective】The purpose of the research is to make clear the effects of photosynthesis,dry matter and yield of cotton under the conditions of CO2 elevation and nitrogen application in order to provide the theoretical foundation for the comprehensive evaluation of farmland ecosystem.【Method】In the field of open system,semi-closed open top chamber was used and designed by a split plot. CO2 concentration was set up as the main plot,at the same time,different nitrogen levels were set up as deputy district. During the full flowering stage of cotton,CO2 was released between12：00 and 15：00 for 20 days. The research was carried outthrough investigating the response in this condition and by measuring photosynthesis,SPAD,dry matter and yield of cotton.【Result】The photosynthetic rate of cotton during inverse fourth leaf satage increased most in the concentration of CO2 increased by 0. 5 times and 450 kg/hm2 nitrogen levels condition,reaching 121. 1%,however,under the condition of no nitrogen application increased less,only 47. 2%,and decreased under condition of 150 kg/hm2 and 300 kg/hm2 nitrogen levels. The SPAD results showed that chlorophyll content had a significant positive effect in nitrogen application and CO2 concentration when increased 0. 5 times,however,which would be reduced under the condition of multiple concentrations. Dry matter accumulation after flowering had a positive effect in the elevation of CO2 and nitrogen fertilization. Boll weight and yield by elevation of CO2 treatment were higher than the background concentration treatment,the maximum increase was 0.3 g and yield was 428. 6 kg/hm2（P 0.05）,with increase extent of 6% and 6.6%. In the 0-300 kg/hm2 nitrogen within the boll showed an increasing trend,at the same time the lint decreased significantly under elevation of CO2,however,which could be bettered by increasing amount of nitrogen.【Conclusion】Elevating CO2 concentration appropriately within a certain reasonable range with nitrogen fertilization could improve cotton floweri
出处
《新疆农业科学》
CAS
CSCD
北大核心
2014年第8期1430-1436,共7页
Xinjiang Agricultural Sciences
基金
国家自然科学基金项目"CO2浓度升高对新疆干旱区棉花-土壤系统的影响机制及其与氮素的耦合作用"(40973061)
农业部公益性行业科研专项"北方旱作农业滴灌节水关键技术研究与示范"(201203012)
国家"863"重大专项"新疆干旱区现代节水农业技术研究与集成"(2006AA100218)
关键词
棉花
CO2浓度
施氮
光合能力
干物质
产量
cotton
concentration of CO2
nitrogen application
photosynthetic ability
dry matter
yield
