Study On Nutrient Status Of Soil And Tree In Main Producing Areas Of Camellia Oleifera In Guizhou Province

Camellia oleifera is a woody oil species originating in China and widely distributed in 18 provinces.Tea oil is a traditional plant edible oil in the south of our country.It is popular for its high content of unsaturated fatty acid.In recent years,Camellia oleifera,as one of the characteristic forestry industries in Guizhou Province,has made good achievements in planting,low conversion and improved seed breeding,making positive contributions to the security of national grain and oil and the construction of ecological civilization.However,with the continuous development of Camellia oleifera industry,many problems also appeared in the Camellia oleifera producing areas in Guizhou Province,such as planting without consideration or extensive management,no fertilization or indiscriminate fertilization,lack of attention to the mutual balance of nutrient elements,and neglect of the supply and demand relationship between soil and tree.Camellia oleifera was malnourished,affecting the growth and production of Camellia oleifera.At present,there are few researches on soil and tree nutrients in the main producing areas of Camellia oleifera in Guizhou Province.The overall and specific conditions of soil and tree nutrients in the main producing areas of Camellia oleifera are still unclear,which seriously restricts the nutrient management of forest land and the high-quality development of Camellia oleifera.Therefore,Camellia oleifera forest in 30 counties(districts)and 90 townships(towns)in 6 cities(prefectures)of Camellia oleifera main planting area of Guizhou Province was selected as the research object to study the nutrient status and spatial distribution characteristics of soil and tree in Camellia oleifera main producing areas.To provide a theoretical basis for scientific fertilization.The main research results are as follows:(1)The p H of the soil in the main producing areas of Camellia oleifera in Guizhou province is between 3.77-7.29,and the overall soil was acidic.The proportion of organic matter content of 0-20 cm layer greater than 20 g/kg was 67.78%.The contents of total nitrogen and total potassium in the soil of the three layers in Liuanshui City were in the appropriate range.The contents of total phosphorus,alkali-hydrolyzed nitrogen and available potassium in the soil of 40-60 cm layer were 74.45%,82.60% and 97.78%,respectively.The contents of available phosphorus in the soil of the three layers were all less than 10 mg/kg.The minimum value of exchangeable calcium was 529.7 mg/kg,and the exchangeable magnesium content was between 19.72 and 372.50mg/kg.The average contents of available iron,available manganese,available copper,available zinc and available boron in three layers of soil were 30.14 mg/kg,30.7 mg/kg,0.76 mg/kg,3.73 mg/kg and 0.47 mg/kg,respectively.The majority(80%)of soil nutrient nugget coefficients were between 25% and 75%,with moderate spatial correlation,and were influenced by random and structural factors.(2)The average contents of nitrogen,phosphorus and potassium in the leaves of Camellia oleifera were 11.76 g/kg,1.35 g/kg and 6.44 g/kg,respectively.The nugget coefficient of nitrogen was 34.42%,showing moderate spatial correlation.The average content of medium element calcium is 6.75 g/kg,and the average content of magnesium is 3.65 g/kg,and the coefficient of variation is small.The average contents of Fe,Mn,Cu and Zn were 117.54 mg/kg,1407.78 mg/kg,3.16 mg/kg and 7.33 mg/kg,respectively.The nugget coefficient of Fe was the lowest,which was 24.39%,showing strong spatial correlation and little influence by random factors.(3)The average contents of nitrogen,phosphorus and potassium in the annual branch of Camellia oleifera in Guizhou Province were 6.35 g/kg,0.79 g/kg and 7.95 g/kg,respectively.The gold nugget coefficient of potassium was the lowest(21.79%),showing a strong spatial correlation.It is less affected by random factors.The average content of medium element calcium is 8.72 g/kg,and the average content of magnesium is 4.26 g/kg.The nugget coefficient of magnesium is less than 25%,and the spatial correlation is strong.The average contents of Fe,Mn,Cu and Zn were 193.77 mg/kg,1701.61 mg/kg,4.54 mg/kg and 11.11 mg/kg,respectively,showing moderate spatial correlation.(4)Antagonistic and synergistic effects existed between soil nutrients and tree nutrients in Camellia oleifera,Guizhou,and the synergistic effects were as follows: soil total nitrogen,soil organic matter and soil total phosphorus;Soil available phosphorus,leaf manganese and leaf magnesium;Leaf nitrogen and leaf phosphorus;Leaf iron and annual branch zinc;Annual branch iron and annual branch copper.Soil organic matter and soil available phosphorus showed significant antagonistic effects.Soil total potassium and leaf iron;Soil available boron and annual branch potassium,manganese;Leaf nitrogen and leaf zinc;Leaf iron and annual branch nitrogen;Annual shoot nitrogen and annual shoot copper.The relationship between Camellia oleifera soil and tree body is complex,not simple correspondence,and these synergistic or antagonistic effects can be considered in the future scientific fertilization.