Response Of Soil Physical And Chemical Properties,Shoot Yield And Quality Of Pleioblastus Amarus Forest To Different Densities And Fertilization Treatments

Pleioblastus amarus is a kind of high-quality local bamboo species with wide distribution and high economic value in China.It has a wide range of uses,high utilization value and use value,and has a good development prospect.However,most of the existing Pleioblastus amarus forests are in the state of natural growth and extensive management.The output and quality of the main product bamboo shoots are low,and the economic efficiency is low,which restricts the sustainable development of the bamboo industry.In order to find out the effect of density and nutrient on the yield and quality of Pleioblastus amarus,the density（D）,nitrogen（N）,phosphorus（P）and potassium（K）of Pleioblastus amarus Forest in Shuanghe Town,Changning County,Yibin City were used as the research object,and 10 treatments（D₁N₁P₁K₁、D₁N₂P₂K₂、D₁N₃P₃K₃、D₂N₁P₂K₃、D₂N₂P₃K₁、D₂N₃P₁K₂、D₃N₁P₃K₂、D₃N₂P₁K₃、D₃N₃P₂K₁、CK）were set up.Through the analysis of soil physical and chemical properties,bamboo shoot yield,soluble sugar,soluble protein,amino acid and seasonal dynamic observation,the influencing factors and rules of bamboo shoot yield and quality were discussed,so as to provide reference for the establishment of reasonable management measures.（1）Before and after treatment,the soil p H decreased,and there was no significant difference in the soil p H of Pleioblastus amarus.The content of soil organic matter was significantly increased by different density fertilization treatments.The content of soil organic matter decreased continuously during the period of shoot emergence,but the content of soil organic matter in each treatment was significantly higher than CK,indicating that the density fertilization treatment was conducive to the accumulation of organic matter.When analyzing the content of soil organic matter in different periods of the same treatment,it was found that the content of soil organic matter in CK treatment was significantly higher than that in other periods（p<0.05）,which was consistent with other treatments.The contents of soil organic matter in T2,T3,T7,T8 and T9 treatments were all in the shooting stage（Early stage of bamboo shoot>Mid shoot stage>After bamboo shoots stage）>March 2019>July 2018,and there were significant differences between the stages（p<0.05）.（2）Under the treatment of density fertilization,the contents of total nitrogen,total phosphorus and total potassium in soil were increased in different degrees,respectively by 40.27-96.38%,0-34.38%and 33.6-46%.There were different significant changes of soil nutrients in different density fertilization treatments during the period of shoot emergence,but the trend was lower than that before shoot emergence.（3）The treatment of density fertilization can significantly increase the output of Pleioblastus amarus shoots,with an increase of 53.69-99%,and the average output of T5 treatment is the highest,with an increase of 2120 kg/hm².There was a significant difference in the yield among the density fertilization treatments,T5 treatment was significantly higher than other treatments,T7,T8,T9 treatment was significantly higher than T1,T2,T3,T4,T6 treatment,indicating that the density fertilization was conducive to the increase of bamboo shoot yield,but the increase degree of different density fertilization treatments was not the same.According to the regression model and statistical analysis,the best scheme of bamboo shoot yield is that the application amount of density,nitrogen,phosphorus and potassium is 18000 plants/hm²,230kg/hm²,180kg/hm² and 84kg/hm² respectively.The effect of density,N,P,K on it was P>density>K>N.（4）Density fertilization can effectively improve the quality of Pleioblastus amarus and promote the accumulation of soluble sugar,protein and amino acid.The content of soluble sugar and protein increased by 12.5-112.5%and 13.37-100.54%respectively.Through regression model and statistical analysis,the best solution of soluble sugar in bamboo shoots was 18000 plant/hm²,345 kg/hm²,180 kg/hm²,84kg/hm² respectively;The best scheme of soluble protein was density,N,P and K application amount of 14000 plants/hm²,345 kg/hm²,180 kg/hm² and 168 kg/hm²respectively.From the regression model and statistical analysis,it can be seen that density,nitrogen and potassium have significant effects on the content of soluble sugar and protein in bamboo shoots.For the essential amino acids of bamboo shoots,density,nitrogen,phosphorus and potassium all had significant effects on them.The best application amount of density,nitrogen,phosphorus and potassium were 14000plants/hm²,345 kg/hm²,180 kg/hm² and 252 kg/hm² respectively;For fresh amino acids,the effect of density,N,P and K is K>density>P>N,and the best application amount of density,N,P and K is 14000 plants/hm²,115 kg/hm²,180 kg/hm² and 252kg/hm² respectively;For the total amount of amino acids,density,nitrogen and potassium had a significant impact on the total amount of amino acids in the bamboo shoots,while phosphorus had no significant impact on the content.Density and potassium had the greatest impact on the total amount of amino acids.The best application amount of density,nitrogen,phosphorus and potassium were 14000plants/hm²,115 kg/hm²,180 kg/hm² and 252 kg/hm² respectively.In conclusion,the density fertilization treatment can not only effectively improve the soil nutrient content,but also significantly increase the yield and improve the quality of Pleioblastus amarus.The optimum density,N,P and K application rates of Pleioblastus amarus were 18000,plants/hm² 230k kg/hm²,180kg/hm² and 84 kg/hm² respectively.Therefore,in the cultivation and management of the Pleioblastus amarus forest,we can consider to adopt the reasonable density fertilization treatment to carry out the management of the Pleioblastus amarus forest,so that the Pleioblastus amarus forest can be sustainable development for a long time.