Effects Of Fertilization And Intercropping On The Production And Quality Of Platycodon Grandiflorum

The field experiments were conducted in 2015-2016 in the Shandong Agricultural University Chinese medicine cultivation garden,selected the Japanese three cherry pepper and Boshan annual Platycodon grandiflorum as the test material.Two fertilizer dosages(conventional and increased fertilizer)and three P.grandiflorum/pepper intercropping models(every three,four and five rows of P.grandiflorum were cultivated between every two rows of pepper)were set.The conventional fertilizer dosage was designed according to monocultural P.grandiflorum under soil being not cultivated P.grandiflorum,with fertilization of urea480kg·ha-2,superphosphate 339 kg·ha-2,potassium sulfate 255 kg·ha-2,increased fertilizer dosage was 1.5 times of conventional fertilizer dosage.The field experiments investigate the effects of P.grandiflorum/pepper intercropping on soil nutrient,enzyme activity,microbes,dry matter distribution and accumulation,nutrient uptake,P.grandiflorum yield and quality under different fertilization conditions.The main results are shown as follows:1 Effects of intercropping on soil microenvironment under different fertilization1.1 Effects of intercropping on soil nutrient under different fertilization P.grandiflorum/pepper intercropping increased the consumption of available N and available P under conventional fertilizetion.The contents of available N and available P were further increased by increasing fertilization.While the content of available potassium decreased,and with the decrease of P.grandiflorum lines,Rapid consumption of potassium gradually increased,increasing the amount of fertilizer consumption reduced.Under the condition of increased fertilization,P.grandiflorum/pepper 3:2 had the highest content of available N and available K and P.grandiflorum/pepper 4:2 had the highest content of available P.1.2 Effects of intercropping on soil enzyme activity under different fertilization P.grandiflorum/pepper intercropping significantly increased soil urease activity from May to June,decreased soil sucrase activity in August and soil phosphatase activity,and had nosignificant effect on soil catalase activity under different fertilization.The increased fertilization conditions were beneficial to the increase of soil sucrase activity,phosphatase activity and catalase activity,and effectively inhibited the activity of soil urease.Monoculture P.grandiflorum had the highest urease activity under conventional fertilization.While P.grandiflorum/pepper 3:2 had the highest sucrase activity and P.grandiflorum/pepper 4:2 had the highest phosphatase activity and catalase activity under increased fertilization.1.3 Effects of intercropping on soil microbes under different fertilization The number of bacteria in each treatment increased gradually.P.grandiflorum/pepper intercropping under different fertilization conditions promoted the propagation of bacteria and inhibited the propagation of fungi and actinomycetes.The number of bacteria and fungi reached the maximum in September and the number of actinomycetes reached the maximum in June.Under the condition of increased fertilization P.grandiflorum/pepper 4:2 had the highest number of bacteria and fungi,while P.grandiflorum/pepper 5:2 had the highest number of actinomycetes in September.2 Effects of intercropping on Platycodon grandiflorum under different fertilization2.1 Effects of intercropping on Platycodon grandiflorum dry matter distribution and accumulation under different fertilization P.grandiflorum/pepper intercropping changed the growth environment of root and the dry matter allocation pattern of P.grandiflorum,and promoted the dry matter transfer to the root system.The proportion of dry matter distribution increased with the increase of fertilizer amount.Under the condition of conventional fertilization,the highest dry matter accumulation of P.grandiflorum was the intercropping model that four rows of P.grandiflorum cultivated between every two rows of pepper.While the highest dry matter accumulation of P.grandiflorum was the intercropping model that three rows of P.grandiflorum cultivated between every two rows of pepper under the condition of increased fertilization.2.2 Effects of intercropping on Platycodon grandiflorum nutrient uptake under different fertilization The intercropping model was beneficial to the accumulation of phosphorus in the roots of P.grandiflorum under different fertilization.The accumulation of nitrogen,phosphorus and potassium of the P.grandiflorum/pepper 5:2 intercropping model of were higher thanmonoculture under conventional fertilizer dosage.Under the condition of increased fertilization,P.grandiflorum/pepper 4:2 was the best intercropping association.The accumulation of nitrogen and potassium in the roots and stems of P.grandiflorum was higher than that of other intercropping models in July and August,The accumulation of nitrogen was the highest in September,and the difference between other treatments was significant.2.3 Effects of intercropping on Platycodon grandiflorum yield and quality under different fertilization Under different fertilization conditions,P.grandiflorum/pepper intercropping could significantly reduce lateral root yield and root rot incidence,increase the content of total protein.Total root yield and taproot yield of P.grandiflorum was increased compared with monoculture under increased fertilizer dosage,Considering root yield and quality,the intercropping association,P.grandiflorum/pepper 4:2 was the best intercropping association to enhance root yield and quality of P.grandiflorum.