Effects Of Nitrogen Application Rate And Intercropping Astragalus Sinicus On Growth,Yield And Quality Of Atractylodes Macrocephala Koidz.

Atractylodes macrocephala Koidz.(AM)is a perennial herb of Atractylodes in Compositae,and it is one of the bulk medicinal materials.High medicinal value,market demand.In this study,AM was used as the research object,four nitrogen application levels(denoted as N1,N2,N3,N4)were set,and no nitrogen application(N0)was used as the control.Nitrogen fertilizer reduction experiments were carried out under two planting patterns of Atractylodes macrocephala monoculture(denoted as M),Atractylodes macrocephala and Astragalus sinicus intercropping(denoted as I).The effects of nitrogen application on agronomic traits,leaf enzyme activity and chlorophyll content,nutrient accumulation,yield,quality,root soil nutrient and enzyme activity of AM under two planting patterns were explored.In order to provide reference for nitrogen fertilizer reduction and efficiency improvement of AM.The results are as follows :1.Under the two planting modes,the plant height,stem diameter and branch number of AM conformed to the ‘S’ growth curve,and increased rapidly during the vegetative growth period and slowly after entering the reproductive growth period,but the number of leaves increased first and then decreased with the extension of growth time.Compared with no nitrogen application,nitrogen application increased plant height,stem diameter,leaf number and branch number,but decreased with the decrease of nitrogen application.2.Under the two planting modes,nitrogen application was conducive to reducing POD activity and MDA content in leaves.But different planting patterns had different effects on leaf SOD activity,under intercropping mode,leaf SOD activity decreased with the decrease of nitrogen application rate,while under monoculture mode,leaf SOD activity increased first and then decreased with the decrease of nitrogen application rate.3.Under the two modes,the total chlorophyll content of each treatment increased first and then decreased with the extension of AM growth time,and the highest was in the budding stage.Under intercropping mode,the total chlorophyll content increased first and then decreased with the decrease of nitrogen application rate,and the content of IN3 treatment was the highes,while under monoculture mode,the total chlorophyll content decreased with the decrease of nitrogen application rate.4.During the growth period of AM,N,P,K elements accumulated rapidly in vegetative growth stage,and transferred to roots and buds in reproductive growth stage.Compared with no nitrogen application,nitrogen application increased the contents of N,P and K in various organs of AM.Under the intercropping mode,the P and K contents in each treatment decreased with the decrease of nitrogen application rate,while under monoculture mode,the N content in each organ decreased with the decrease of nitrogen application rate.5.Compared with non-N treatment,N treatment improved the yield and quality of AM.Appropriate nitrogen reduction under intercropping mode was helpful to increase the yield of AM.The results of two-factor variance analysis showed that the N3 level under intercropping was significantly higher than that under single cropping,increasing by 27.73%.The contents of polysaccharides,atractylenolide I,atractylenolide II,atractylenolide III and atractylone in IN3 treatment under intercropping were increased by 3.82%,1.49%,9.99%,16.29% and 4.58%,respectively,compared with those in MN4 treatment under monoculture.6.Compared with no nitrogen application,nitrogen application increased root soil nutrient content of AM,and after a growth cycle,soil nutrients decreased.Under the two planting patterns,soil enzyme activity was enhanced by nitrogen application,and decreased with the decrease of nitrogen application.During the growth period of AM,soil enzyme activity gradually decreased with the maturity of AM.The results of two-factor analysis of variance and comprehensive analysis of membership function showed that the intercropping effect of AM and Astragalus sinicus was better than that of AM monoculture.Under the intercropping mode,the best treatment of nitrogen reduction was IN3,and the nitrogen application rate(N)was 155 kg/ha.