LED补光和根区加温对日光温室起垄内嵌式基质栽培甜椒生长及产量的影响

Effect of LED supplemental lighting and root zone heating on growth and yield of soil ridged substrate-embedded sweet pepper in solar greenhouses in China

田间条件下采用起垄内嵌式基质栽培(soil ridged substrate-embedded cultivation,SRSC)方法,研究了日光温室LED冠层补光和电热线根区加温对甜椒生长和产量的影响。该试验设不加温不补光对照(CK)、根区加温15℃处理(T15)、根区加温18℃处理(T18)、单一补光处理(L)、根区加温15℃+补光处理(T15+L)、根区加温18℃+补光处理(T18+L),共6个处理。结果表明,与对照相比,根区加温均能提高SRSC甜椒根区的温度,但根区温度仍呈现出随环境温度变化而变化的趋势,T18的根区全天保持较高温度。根区热通量的变化与根区温度变化相对应,T15和T18处理的根区热通量昼夜变化较CK剧烈,其根区侧面白天向内传热滞后,晚间侧面向外传热提前,传递量增加;根区垂直方向白天向内传热滞后,传递量减少,晚间垂直向外传热提前,但传递量增加。T15和T18均显著提高了甜椒的株高、冠层厚度和冠层直径,且T18比T15效果更明显。T15对甜椒的地上及地下干鲜重没有显著的提升作用,而T18的提升效果显著。根区加温补光处理的甜椒生物量普遍高于单一根区加温或补光处理,其中T18+L处理提升效果显著优于T15+L处理。T15、T18和L相对CK均提高了甜椒单产,单产分别提高30.74%、53.0%和14.81%。而根区加温和LED补光协同作用比单一的根区加温或冠层补光都能表现更好的增产效果,T15+L和T18+L分别比T15和T18的产量分别提升32.86%和15.50%,分别比L产量提升51.29%和53.87%。总之,根区加温与LED补光是日光温室甜椒增产有效的调控措施,两者在增加单株产量上存在显著的协同效应,二者共同作用比单一作用效果更加明显,且根区加温对甜椒生长和产量的促进效果比冠层补光更加显著,在实际生产中具有重要的指导意义。

In order to deal with resource and environmental issues of soil cultivation and sunlight deficiency and to enhance root-zone temperature for crop cultivation during low winter temperature periods in solar greenhouses in China, a field study was conducted with soil-ridged substrate-embedded cultivation （SRSC） method under greenhouse conditions to investigate the effect of root-zone heating and LED supplemental lighting on the growth and yield of sweet pepper. Six treatments were designed in the study, including the control without heating and lighting （CK）, root zone heating at 15 ℃ （T15）, root zone heating at 18 ℃ （T18）, sole LED supplemental lighting （L）, root zone heating at 15 ℃ plus LED supplemental lighting （T 15＋L） and root zone heating at 18 ℃ plus LED supplemental lighting （T 18＋L）. The results showed that compared with CK, heating increased the root zone temperature under SRSC and root zone temperature changed with change in temperature of the environment. Root zone temperature under T 18 was high throughout the day. Heat flux under T15 and T18 fluctuated with root zone heating and changed more violently than under CK. The data showed a lag in the time of inward heat transfer and an advance in the time of outward heat transfer with increasing root zone temperature in lateral and vertical directions, and there was more diurnal heat transfer in the vertical root zone. T15 and T18 treatments significantly increased plant height, canopy height and diameter of sweet pepper, which were more obvious under TI8 than T15 treatments. The growth parameters of sweet pepper further improved with simultaneous root zone heating and LED supplemental lighting. Fresh and dry shoot and root weights of sweet pepper increased significantly under T18 than under T15 treatment. Plant biomass under simultaneous root zone heating and LED supplemental lighting was higher than that under root zone heating or sole LED supplemental lighting, and that under T 18＋L treatment was highest. Compared with CK, T 15, T 18 and L treatments improved sweet pepper yield by 30.74%, 53.0% and 14.81%, respectively. Furthermore, sweet pepper yield under T15＋L and T18＋L were respectively 32.86% and 15.50% higher than that under T15 and T18 and also 51.29% and 53.87% higher than that under L treatment. In summary, root zone heating and LED supplemental lighting proved to be beneficial agronomical soil cultivation measures in solar greenhouse conditions in China with high vegetable productivity and remarkably synergistic effect on single plant yield of sweet pepper. The interaction of root zone heating and LED supplemental lighting was more obvious than that of the single effect of the treatments. Also the effect of root zone heating on the growth and yield of sweet pepper was more obvious than that of LED supplemental lighting. The results of the study provided an important guide in actual crop production under solar greenhouse conditions in China.