Study On Patterns And Effect Of Intercropping Under Plantation Of Litsea Cubeba

Litsea cubeba is a deciduous shrub or small tree of the genus ginger in camphor family.It is a special kind of woody spice tree with many uses.In this study,the six-year-old L.cubeba of the same family was used as experimental material,and the under plantation intercropping patterns of L.cubeba were different from those of Trifolium repens,Trifolium pratense,Festuca elata,Zinnia elegans and Tagetes erecta,respectively.The effects of different intercropping patterns on tree growth,photosynthesis,fruit economic traits and oil yield,soil physical and chemical properties,soil equivalent ratio and economic benefits of plantation soil were studied and analyzed.The aim of this study was to screen out the suitable intercropping patterns by studying the effects of different intercropping patterns under the plantation,so as to provide.theoretical support and production guidance for the industrial production mode of L.cubeba.The main research results are as follows:(1)Different intercropping patterns had positive effects on tree growth and fruit economic characters of L.cubeba.The plant height increment of L.cubeba intercropping with T.erecta,T.pratense and Z.elegans was 83.5%,45.2%and 31.4%higher than that of the control,respectively.The ground diameter increment of intercropping F.elata was significantly different from that of the control,which was 73.3%higher than that of the control,and the chlorophyll content of litsea cotyledon leaf was increased.Except for the treatment of intercropping T.erecta,the transverse and longitudinal diameters of the fruits of other intercropping L.cubeba were significantly different from the control.The transverse and longitudinal diameters of the fruits of intercropping F.elata were 12.3%and 12.29%larger than the control.The exocarp thickness of L.cubeba fruits under different intercropping treatments was significantly different from that of the control.The exocarp thickness of intercropping F.elata was 44.39%higher than that of the control.The individual fruit weight of intercropping F.elata,Z.elegans and T.pratense was 34.56%,16.16%and 14.92%higher than that of the control,respectively.(2)The oil yield and citral content of L.cubeba fruit were increased by different intercropping patterns.The yield of essential oil of intercropping F.clata,T.erecta,T.rcpens.Z.elegans and T.pratense fruits was significamly different from that of the control.and was 45.84%.36.29%,31.44%,23.68%and 14.82%higher than that of the control,respectively.The content of total citral in the essential oils of the intercropping T.repens,T.pratense,F.elata,Z.elegans and T.erecta fruits was 33.46%,25.49%,28.42%,33.29%and 33.15%higher than that of the control,respectively.(3)The results of different intercropping patterns on photosynthesis of L.cubeba were as follows:Intercropping of T.repens could enhance the adaptability of L.cubeba to strong light,the maximum photosynthetic capacity and the adaptability to high CO2 environment.Intercropping T.pratense effectively reduced the temperature of L.cubeba leaves and improved the ability of L.cubeba to use weak light.The photosynthetic capacity and low light utilization capacity of L.cubeba were enhanced by intercropping F.elata,and the net photosynthetic rate was 5.18μmol·m-2·s-1 per day.The water use efficiency of the leaves of L.cubeba intercropping F.elata was 32%higher than that of the control.The photosynthetic capacity and adaptability to strong light of L.cubeba were enhanced by intercropping of Z.elegans.The average daily net photosynthetic rate was 4.89 μmol·m-2·s-1.The mean water use efficiency of L.cubeba intercropping T.erecta was 26%higher than that of the control,and the ability to adapt to high concentration CO2 environment was strong,but the assimilation ability to low concentration CO2 was low.(4)Different intercropping patterns had different effects on soil properties of L.cubeba plantation.The soil layer temperature of L.cubeba plantation could be decreased by different intercropping patterns.The soil pH of L.cubeba intercropping with T.repens.T.pratense,F.elata and Z.elegans was lower than that of control and intercropping with T.erecta.Except for intercropping of T.repens,other intercropping treatments could significantly increase soil water content in L.cubeba plantation.The soil moisture content of L.cubeba intercropped with T.erecta was the highest,which was 16.15%higher than that of control.Intercropping of Z.elegans,F.elata and T.erecta significantly increased soil total nitrogen content,which was 150.23%,141.15%and 53.64%higher than that of the control treatment,respectively.Intercropping of T.pratense significantly increased soil ammonium nitrogen content,intercropping of T.pratense and F.elata significantly increased soil available phosphorus and available potassium contents.The soil organic matter content of intercropping L.cubeba was 62.79%,58.31%.42.61%,29.15%and 21.02%higher than that of the control,respectively.(5)Land equivalent ratio,economic benefit and comprehensive evaluation of different intercropping patterns.The land equivalent ratio of different intercrop ping patterns were all greater than 1,indicating that the intercropping of T.repens,T.pratense,F.data,Z.degans and T.erecta under L.cubeba plantation had certain advantages.The intercropping advantages of T.erecta and Z.elegans were 1.892 and 1.818,respectively.L.cubeba intercropping with F.elata and T.erecta had the highest economic benefit.The principal component analysis of different intercropping patterns of L.cubeba showed that the intercropping pattern of F.elata under plantation was the best,followed by intercropping of Z.elegans.