砂石地基质栽培番茄日光温室CO_2浓度的变化规律研究

以越冬茬番茄为试验作物,研究了番茄砂石地基质栽培日光温室内CO2浓度在不同生育进程中的变化规律.结果表明:生育前期,室内CO2浓度日变化呈不规则的"U"型,生育后期,为不规则的"W"型.不同季节通风对室内CO2浓度的影响不同.在温度较高的生育前期,通风前温室CO2浓度高于大气浓度,通风降低了温室CO2浓度;在温度较低的生育后期,通风前温室CO2浓度低于大气浓度,通风可提高室内CO2浓度.但为了保持温室温度,生育后期通风时间应较短,风口也应较小,室内CO2浓度一直处于较低水平,不能满足作物光合作用的需要.番茄苗期以外各生育阶段的CO2浓度均低于800μL/L,且每天低于外界大气CO2浓度的时间达6.0～8.3h.因此,砂石地日光温室番茄基质栽培需要进行CO2施肥.

Variations of CO2 concentration in solar greenhouse on sand land with tomato substrates cultivation

The variations of CO2 concentration in solar greenhouse on sand land during the substrate cultivation of overwintering tomato were studied.The results showed that at the earlier growth stage,diurnal variations of CO2 concentration showed an irregular "U" shape,and at the later growth stage,diurnal variations of CO2 concentration showed an irregular "W" shape.Ventilation in different seasons had different effects on CO2 concentration in solar greenhouse.At the earlier stage of growth with high temperature,CO2 concentrations in greenhouse were higher than that outside before the ventilation,and the ventilation reduced CO2 concentration in solar greenhouse.At the later stage of growth with low temperature,CO2 concentrations in greenhouse were lower than that outside before the ventilation,and the ventilation increased CO2 concentration in solar greenhouse.But in order to contain the temperature in solar greenhouse in the low temperature season,short time ventilation and small outlet lead to lower CO2 concentration,which could not meet the needs of crop photosynthesis.The CO2 concentrations in solar greenhouse were all less than 800 μL/L during the solid substrate cultivation of tomato except seedling stage.The time when the CO2 concentrations in greenhouse were lower than that outside was 6.0～8.3 h per day in low temperature season.It was suggested that the application of CO2 would be needed in solar greenhouse on sand land during the solid substrate cultivation of overwintering tomato.