Studies On The Nutrient Diagnosis And Fertilization Effect Of Cinnamomum Camphora Seedlings

Cinnamomum camphora,mainly distributed in the southern provinces of China,are beautiful,Evergreen.C.camphora is not only an excellent timber tree species,but also an important raw material species for flavors,spices,oil chemicals and medicine.At present,the management level of C.camphora plantation in China is not high,management is extensive,there still have some problem should be overcome,such as the imbalance nutrient and production during the process of plantation cultivation.Besides,the study on the diagnosis and fertilization of C.camphora is still in the exploratory stage.This paper focused on soil fertility,tree growth and nutrient status in Anfu C.camphora plantation.The DRIS method was used to diagnose the C.camphora plantation,and the order of fertilizer requirement was obtained.On this basis,the annual C.camphora seedlings were used as test materials,and ternary quadratic rotation combination design was applied for indoor pot fertilization experiments to study the effects of different N,P,and K fertilization on the growth of C.camphora,and select the most suitable fertilizing formula for growth to guide the scientific fertilization.At the same time,the annual C.camphora seedlings were used as experimental materials to study the growth and physiological status of C.camphora seedlings under Cu and Zn treatmenes.The main findings are as follows:1.The results of the soil survey of C.camphora plantation in Anfu County showed that,the floodplain soil has poorer water retention capacity and lower organic matter content than the lowland mountains.The low hilly soils have higher interception and storage capacity of rainfall than the floodplain,which was more favorable to the cultivation of C.camphora.The soil in the main planting area of Anfu C.camphora plantation is acid to strong acidic soil,the content of organic matter is moderate and low,the overall soil fertility level is generally low,especially the large amount of element nutrient content which plays an important role in forest growth.The soil nutrient content can be improved by balanced fertilization of forestland,which is supplemented by a large number of elements,but it also needs to be combined with tree nutrition diagnosis to improve fertilizer utilization rate and realize the efficient cultivation and sustainable management of C.camphora plantation.2.The optimum ranges for nutrient diagnosis of Fengcheng C.camphora plantation leaves N,P,K,Ca,Mg,Zn,Mn,Fe and Cu content were as follow:?8.871±1.640?,?1.949±0.374?,?3.909±0.432?,?11.658±1.337?,?10.050±0.968?,?0.290±0.036?,?0.301±0.031?,?0.264±0.034?and?0.035±0.003?g/kg,what can be used to determine the nutritional status of C.camphora plantations.3.Using DRIS graphic method and index method to diagnose the nutrient of Fengcheng C.camphora plantation,the required fertilizer order?Zn=P>Ca>N>K=Cu>Mn=Mg>Fe?which was diagnosed by graphic method in the low-yield group was basically the same to index method?Zn>P>Ca>N>K>Cu>Mn>Mg>Fe?.Compared with the two methods,it is found that the graphic method could see the nutrient demand more intuitively,but there was a problem that the order of the fertilizer in the same equilibrium scope cannot be distinguished;The index method can accurately reflect the nutrient abundance of C.camphora leaves,but it was difficult to observe the nutrient requirement.4.The content of N,P,Ca and Zn nutrients in Fengcheng C.camphora plantation were found to be deficient,and the content of Mg,Mn and Fe were relatively surplus.Based on the diagnosis of C.camphora plantation,the DRIS index grading standard of C.camphora was developed,which can be used to diagnose the balance of the nutrient elements of C.camphora,and to instruct the C.camphora plantation to make rational fertilization in time.5.To carry out the pot experiment of fertilization with different proportion of N,P and K,the fertilization design was carried out using ternary two times universal rotational combination,and finally the ternary two regression equation model was established.The high increment model of C.camphora seedling was Y=37.580-1.636X₁+1.117X₂-0.865X₃-0.225X₁X₂-1.475X₁X₃-2.348X₂X₃-1.224X₁²-0.573X₂²-0.876X₃²,it can be concluded that the optimum seedling height increment is 43.50cm,and the best fertilization scheme is:N 5.01 g/pot,P 6.00 g/pot,K 0.00 g/pot.The incremental model of C.camphora seedling was Y=3.694-0.216X₁+0.064X₂-0.174X₃+0.020X₁X₂-0.125X₁X₃-0.135X₂X₃-0.169X₁²+0.045X₂²-0.034X₃²,and the optimal ground diameter increment is 4.51 mm,the best fertilization scheme was:N 4.71 g/pot,P 6.00 g/pot,K 0.00 g/pot.The biomass model of C.camphora seedlings was Y=28.093-1.372X₁+0.213X₂-1.154X₃-1.366X₁X₂+0.291X₁X₃-1.531X₂X₃-1.680X₁²-0.505X₂²-1.223X₃²,and the optimal biomass was 32.41 g,the best fertilization scheme was:N 1.18 g/pot,P 6.00 g/pot,K 0.09 g/pot.The demand of the growth of C.camphora seedlings for a large amount of nutrients was P,N and the minimum requirement for K.6,Through the addition of Cu,Zn and compound treatment to carry out experiment,it was found that the root length,root number,leaf area,leaf number,seedling height,diameter and biomass under 300⁵00 mg/kg treated with Cu and Zn stress were significantly smaller than those in control group.As a whole,300⁵00mg/kg Cu and Zn stress treatment will inhibit the growth of C.camphora seedlings,the inhibition of Cu treatment is stronger than Zn treatment.7,To Cu and Zn stress treatment of C.camphora seedlings osmotic adjustment substances,the analysis of photosynthetic pigments and antioxidant enzymes showed that the content of proline in the leaves of C.camphora seedlings decreased with the increase of concentration,and the growth was seriously affected;the content of photosynthetic pigments was inhibited,the ratio of Chl/Car decreased,and the leaf yellowing phenomenon appeared.The activities of SOD and POD in leaves showed a maximum at 400 mg/kg,and began to decline at 500 mg/kg,and were all higher than those of the control.The results showed that the C.camphora seedlings had strong ability to scavenge ROS under heavy metal stress,had certain tolerance under heavy metal stress,and had the potential to repair the polluted soil with Cu and Zn.8.Under the treatment of Cu and Zn stress,the Pn,Gs and Tr of C.camphora seedlings decreased significantly with the increase of heavy metal stress,while the Ci increased with the increasing of stress.The treatment of 300⁵00 mg/kg Cu and Zn will inhibit the normal growth of C.camphora seedlings,stomatal closure,weakening photosynthesis,resulting in the accumulation of CO2 between cells.