枣与棉花间作巷道内的光环境研究

Study on Light Environment in Intercropping Alley of Jujube and Cotton

【目的】枣是新疆环塔里木盆地特色林果栽培面积最大的树种,环塔里木盆地枣树的栽培大多与农作物间作。【方法】为了探明枣与农作物间作系统间作巷道内的光环境变化对农作物产量形成的影响,本研究以环塔里木盆地枣与棉花间作系统为研究对象,通过度量与棉花间作条件下枣树间作巷道内棉花不同生育时期冠层饱和光合有效辐射(PAR)时空窗的大小及其与棉花产量形成的关系,为枣与棉花间作系统的可持续经营提供科学依据。【结果】枣与棉花间作系统间作巷道内达到棉花光饱和点的光量子通量密度持续时间是影响棉花冠层饱和光合有效辐射时空窗大小的决定因素,并随着枣树树龄的增大和栽植株行距的减小而缩短。棉花产量形成受间作巷道内棉花冠层饱和有效辐射时空窗大小的直接影响,并表现出正相关关系。【结论】新疆南疆盆地枣树栽植行距小于4 m的枣与棉花间作系统中,当枣树树龄达到5 a以上,间作巷道内棉花冠层饱和光合有效辐射时空窗已经关闭或趋于关闭,棉花产量与单作棉田相比大幅降低,已不适合继续间作棉花。

[ Objective]Jujube tree area is the largest area of fruit cultivations and often intercrops with crops in Tarim Basin of Xinjiang. [ Method] In this study, the jujube trees of different ages intercrepping with cotton were selected as tested objects, the size of saturated photosynthetic active radiation （PAR） space-tlme window of the cotton canopy in the intercropping alley was measured to study, the effects of the variation of light environment in the intercropping alley on cotton production and to provide a scientific basis and technological approaches for better cultivating intercropping jujube with cotton. [ Result] In the alley of jujube with cotton intercropping, the duration of the photon flux density at cotton light saturation point was the decisive factor that affected the size of saturated PAR space-time window of the cotton canopy, and the duration shortened along with the increase of the age of jujube tree and the decrease of intercropping plots. The size of saturated PAR space-time window of the cotton canopy directly affected on cotton production and showed a positive correlation with it. [ Conclusion ] In South Xinjiang basin, when the intercropping system with jujube planted less than 4 m and the age of jujube tree reached more than 5 a was not fit to intercropping cotton, the saturated PAR space-time window of the cotton canopy in the intereropping alley had shut down or be shut down, and the cotton production greatly reduced comparing with the monoculture cotton fields.