| Eucalyptus is the main tree species in South China,with its fast growth,high yield,strong resistance and straight stem characteristics.Because of its growth to consume large amounts of nutrients,nitrogen is the major nutrient elements for plant growth,both plant growth and physiological characteristics of large hail,however,its supply is far less than the soil the consumption of nitrogen to improve plant growth is an important measure for the development of artificial forest.But at present,nitrogen utilization level is low,nitrogen loss is large,serious waste of resources and cause some negative impact on the environment.Biochar is a kind of organic matter adsorption,stability,can increase soil nutrient timeliness.To promote plant uptake of soil nutrients.Based on Eucalyptus Seedlings of biological carbon and nitrogen fertilizer treatment,the effects of different treatments on the growth of eucalyptus seedlings,physiological and nutrient absorption and utilization,compared with single First,the difference of growth and physiological indexes between Eucalyptus and eucalyptus seedlings was studied,and the contribution of biochar and nitrogen fertilizer to the growth of eucalyptus seedlings was discussed:(1)nitrogen and biochar could promote Eucalyptus seedling height and ground diameter growth.The growth of seedling height and ground diameter is smaller,the nitrogen level reached N2 or biological carbon content of B2,its growth rate is significantly higher than those in control group were untreated,interaction on the promotion of the role is more obvious.The late Eucalyptus seedling height and diameter growth,nitrogen fertilization significantly promote the growth of seedlings,but had little effect on the size.After adding two months of biochar on Eucalyptus seedling ground diameter growth performance is not obvious,the difference was not significant(p>0.05),but the performance of seedling height growth is a positive role in promoting the growth of seedling height and ground diameter the largest amount was third months B3N2,respectively 45.87cm and 4.29mm,were significantly higher than that in other groups.(2)nitrogen and biochar significantly promote dry matter accumulation of Eucalyptus seedling roots,nitrogen promoted eucalyptus seedlings stem and leaf dry matter accumulation,especially in leaf,biochar reached B2 level significantly increased dry matter accumulation in leaves,only adding biochar on stem dry matter accumulation was not obvious.Biological carbon and nitrogen interaction on dry matter accumulation has a strong role in promoting the root,stem and leaf significantly increased plant dry matter accumulation.The whole plant dry accumulation and root showed the same trend of material,nitrogen and biochar significantly accumulated high Qigan provided material,the interaction effect was more evident.The whole plant dry accumulated large amount of B3N2,B2N2,B3N1,B1N2 and B2N1,respectively,were 185.76g/strains,180.80g/strains,174.87g/strains,169.63 g/strains and 168.80 g/strains,66.18%was 70.74%higher than the control group,60.73%,55.91%and 55.15%.(3)nitrogen significantly increased the Eucalyptus seedling photosynthetic pigment content,chlorophyll fluorescence parameters,net photosynthetic rate,stomatal conductance and transpiration rate,are now N2>N1>N0,but decrease the intercellular C02 concentration.Biochar eucalyptus seedlings to promote the synthesis of photosynthetic pigments,with the addition of biochar up to 2%,significantly increased the chlorophyll and carotenoid content,and fully improve the eucalyptus seedlings of F0,Fv/Fm,and qP and qN,enhance the utilization of Eucalyptus leaves of eucalyptus seedlings significantly increased light,net photosynthetic rate,stomatal conductance and transpiration rate,intercellular C02 concentration reduced nitrogen and biological.Interaction effects on Photosynthetic Characteristics of carbon is more significant,the treatment of B3N2 was the mostobvious,but there is no significant difference between most of indexes and B2N2 processing.(4)nitrogen and biochar promote eucalyptus seedlings physiological metabolism,improve the content of soluble sugar,soluble protein and the protective enzyme(POD,CAT,SOD)content were N2>N1>N0,B3>B2>BI>CK,malondialdehyde(MDA)content decreased.Nitrogen soluble protein was significantly higher than the control group,after adding biochar n,(N1,N2)were significantly higher than control group,biochar concentration reached B2 level was significantly higher than that without biochar treatment,B2,B3 had no significant difference among treatments.Nitrogen fertilizer and biochar can significantly improve eucalyptus seedlings three different protective enzymes,SOD enzyme in N1,N2 level no significant differences in biochar treatment,B1,B2 different nitrogen levels significantly,but B3 N1,there was no significant difference of N2 level between Eucalyptus seedling physiological metabolism.Change trend and photosynthetic characteristics were consistent with B3N2,the treatment effect is the best,but with the increase of the biochar.The rate of growth decreased gradually,indicating that the amount of biochar increased gradually,and its influence on the performance was not obvious(5)nitrogen can promote the organs of eucalyptus seedlings roots and leaves of N,P,K content,and Analysis on the content of N significantly,the level of N1 had no significant effect on leaf P,K contents,but significantly increased in Eucalyptus seedlings stems P,K content.Biochar content influence on the plant organ N is not significant,only the level of B3 was significantly higher than the control group,but B2 treatment plant N accumulation was significantly higher than that of CK,and increased the plant organs of P K absorption(K element content in leaves of B1,except for treatment CK)and plant whole plant nitrogen accumulation;interaction with biological carbon all organs were significantly increased N,P,K content of whole plant and plant accumulation.Both fertilizer effect is better than single factor treatment,B3N2 treatment effect is the best,most significantly higher than other treatments(except for Eucalyptus seedling stem P content).Biological carbon and nitrogen fertilizer interaction significantly increased The utilization rate of N,P and K in plants was 17.84%,3.44%and 6.65%.,respectively.The application rate of P and K was increased,but the utilization rate of nitrogen fertilizer was reduced(6)biochar significantly increased the soil pH value added,but nitrogen fertilization significantly decreased soil pH.Nitrogen and biological carbon can effectively improve the soil pH value added interaction,improve the pH.Soil nutrient content was affected by the interaction between nitrogen and biomass carbon,showed N2>N1>N0,B3>B2>B1>CK.nitrogen significantly to improve the soil total nitrogen and available potassium content,biochar concentration reached B2 level significantly increased soil total nitrogen,nitrate nitrogen,ammonium nitrogen,total phosphorus and available potassium content,has little effect on the total potassium content of soil carbon and nitrogen.The biological interaction can significantly improve the soil total nitrogen content of different treatments in all.The content of soil nutrient elements B3N2 highest,significantly higher than the control group,and most significantly higher than other groups(p<0.05).The results showed that biological carbon and nitrogen can improve soil conditions,improve soil nutrient content,promote plant growth and absorption of nitrogen.The combination of biochar and biochar is more conducive to the retention of soil nutrients,and increase the availability of soil nutrients,thereby promoting the absorption and utilization of plants... |
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