麦田开放式昼夜不同增温系统的设计及增温效果

Design of Free Air Temperature Increasing (FATI) System for Upland with Three Diurnal Warming Scenarios and Their Effects

【目的】设计旱地开放式增温系统,并从田间温度变化和冬小麦生育期改变等方面来监测系统的增温效果与可靠性。【方法】参考国际已有增温系统,于2007—2009年在江苏南京设计了中国首个麦田开放式增温系统(freeair temperature increase,FATI),进行冬小麦全天、白天和夜间3种增温试验。【结果】2年试验结果表明,该开放式主动增温系统的增温效果明显。3种情景下各增温小区的均匀有效增温面积在4m2以内,其中全天、白天和夜间增温分别使冬小麦全生育期地下5cm的土温平均增加2.2、1.5和1.8℃,地表温度增加2.2、0.9和1℃,冠层温度增加1.5、0.9和1.1℃。3种增温情景下,冬小麦各关键生育期田间温度的日变化及全生育期日平均温度的变化动态与未增温区的基本一致,增温设施能客观地模拟田间实际气温变化特征。尽管该增温系统略微降低了耕层土壤(0—20cm)水分含量,但降幅仅在0.5—2.2个百分点之间,与对照相比不显著。3种增温情景均对冬小麦生长发育产生了显著影响,全天、白天和夜间增温两年平均分别可以使冬小麦从播种至抽穗期缩短14、9.5和11.5d,灌浆成熟期延长3、3和2.5d。【结论】从增温效果及其对冬小麦的生长影响来看,该套系统基本适用于模拟气候变暖下小麦生产力和品质响应与适应的田间试验研究。

Objective In order to study the responses and adaptation of winter-wheat yield and quality to climate warming at crop system scale in situ,a warming system with free air temperature increasing（FATI） techniques was designed and the warming effects at winter-wheat growing stages were investigated.Method In a field warming experiment,three warming scenarios（AW：all-day warming;DW：day warming;NW：night warming） were conducted during 2007-2009 in Nanjing,Jiangsu,China.Result Two-year results showed that this FATI facility caused significant increments in field micro-environment temperatures.It formed 4 m2 of evenly and reliably warming area both at day time and night time,and the two-year average temperatures in the soil layer of 5 cm of the AW,DW and NW plots were,respectively,2.2℃,1.5℃ and 1.8℃ higher than those in the control plots,and 2.2℃,0.9℃ and 1℃ higher in the field surface,and 1.5℃,0.9℃ and 1.1℃ in the crop canopy.During the whole growing season of wheat,the seasonal and diurnal variations and trends of temperatures in warming plots were closely coupled with those in the control plots,indicating a objective simulation of the future climate warming.Experimental warming also decreased slightly the surface soil（0-20 cm） moisture with a decrement of 0.5%-2.2%,which was not significant compared to the control.Experimental warming with this FATI facility caused significant impacts on wheat growth duration.The durations from the sowing time to the heading stage were,respectively,shortened by 14,9.5 and 11.5 days on an average in the AW,DW and NW plots during the two warming years,and the durations from the heading stage to the harvest were extended by 3,3,and 2.5 days,respectively.Conclusion The experimental results indicate that this experimental warming facility is suitable to study the responses and adaptations of winter wheat to climate warming at system-level in situ,and that great efforts need to be made in the field experimental warming research to improve crop models for regional assessment of crop production under future climate.