| In recent years,with the increase of population,the competition for farmland between agriculture and forestry has become more and more serious,so the agroforestry system has been valued and advocated worldwide.But compound system in increasing the land and the utilization ratio of light energy at the same time,the kind of crop ecological niche overlap between the competition in the light,as a result,this article selects the walnut-rabdosia rubescens and walnut-semen cassiae,two compound systems on the characteristics of time and space distribution of light environment and in the system of two kinds of medicinal herbs physiology,the influence of the growth and quality were studied.The main research results are as follows:(1)The leaf area index of walnut increased first and then decreased from June to September,and reached the maximum value of 1.94 in August.The transmittance of the total radiant light was the minimum of 0.24 in August.In the compound system,the transmittance of all the light quality and far-infrared light in the PAR band were the maximum in July and the minimum in August.In the PAR band of the compound system,the red orange light in June was less than blue violet light,and the blue violet light>red orange light in July,August and September.The transmittance of photosynthetical active radiation(PAR)in different light quality was the lowest and far infrared was smaller than near infrared.The diurnal and spatial variation trends of each wavelengths of light in the compound system showed an inverted "V",and it shows higher in the morning than in the afternoon,and the eastern side is higher than the western side.The average total radiation in the compound system is 40.42%of that in CK.The PAR at M is the maximum,it can reach 54.19%of that in CK.The lowest PAR(W0.5)in the compound system is 21.84 W·m-2,about 16.76%of that in CK.In the PAR,the transmittance of each point in the compound system was B>R.In the compound system,B/PAR,Y/PAR,R/PAR and B/R showed like "W",while R/Fr showed an "M"shape and B/Fr showed an inverted "V" shape.B/PAR,Y/PAR and B/R in the compound system were all higher than CK,while the R/PAR,B/Fr and R/Fr were lower than CK.At the three points:W0.5,M and E0.5,the proportion of blue-violet light is greater than that of red orange light,while the proportion of blue-violet light at E1.5 and W1.5 is smaller than that of red orange light as CK.For each light quality ratio in the compound system,the change of R/FR was the largest,which was 22.60%lower than that of CK,and the change of Y/PAR was the smallest,which was only 0.57%higher than that of CK.Accordingly,should select the plant that mainly absorbs blue violet light crop in compound system.(2)In the walnut-rabdosia rubescens/semen cassia composite mode,the SPAD of rabdosia rubescens and semen cassia in the compound system showed a "W" shape with E0.5,W0.5 and M higher,and the average SPAD of rabdosia rubescens and semen cassia in the compound system was 9.19%and 14.87%lower than that of CK,respectively.The SPAD of rabdosia rubescens was significantly correlated with PAR and R/FR in the compound system,while the SPAD of semen cassia was only significantly correlated with PAR.The diurnal and spatial variation trends of net photosynthetic rate and transpiration rate of rabdosia rubescens and semen cassia showed an inverted "V" shape.The net photosynthetic rate decreased by 56.92%and 55.67%compared with CK,respectively the transpiration rate decreased by 20.98%and 21.99%compared with CK.There was no significant difference in photosynthesis between them.The net photosynthetic rate and transpiration rate were significantly correlated with PAR and SPAD.The plant height of rabdosia rubescens/semen cassia was significantly correlated with PAR in the compound system,and the difference between the plant height in the compound system and CK was increasing in the growth period,lower than CK 29.86%and 48.35%,respectively.The yield of rabdosia rubescens and semen cassia decreased by 81.14%and 68.50%,respectively.The yield of both of them was significantly correlated with PAR and R/FR,that is,R/FR was the main light quality component which affected the yield of Medicinal herbs in the compound system.In the compound system,the maximum oridonin content at W 1.5 was 0.62%,and the average oridonin content in the compound system was 0.57%,which was 34.25%lower than that in CK.The oridonin was significantly correlated with R/IR.The 100-grain weight of the compound system was 10.51%less than that of CK,and there was no correlation between the 100-grain weight and the light quality ratio.Comprehensive analysis of correlation found that the growth indexes of rabdosia rubescens and semen cassia were significantly correlated with R/FR,besides PAR,SPAD,yield and quality of rubescens were significantly correlated with R/FR.In practice,the ratio of red and orange light can be improved by covering red and orange film.(3)The annual income of the walnut-rubescens was 60,850.00 yuan·hm-2,about 2.06%higher than that of walnut-cassia 59,627.09 yuan·hm-2.The rabdosia rubescens is a perennial medicinal material,which can be harvested for many years if planted in one year.Moreover,the industry of rubescens is a local competitive industry,so it is more suitable to promote and plant in the local compound system. |
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