Growth And Nutrient Accumulation In Seedlings Of Cunninghamia Lanceolata Clones With Different Fertilization Treatment

High quality cloned seedlings of Chinese fir(Cunninghamia lanceolata),a fast-growing China-specific plant species dominant in south China,play an important role in Chinese fir forestation.One-year-old clonal seedlings of Chinese fir as experimental materials was fertilizated by several methods including control,conventional fertilization and exponential fertilization in greenhouse to undersdand the character of growth and ecological about Chinese fir.According to the comparison of changing regulation of seedlings height,ground diameter,biomass,chlorophyll content,chlorophyll fluorescence,nutrient accumulation,nitrogen absorption and utilization under different fertlizing methods and different doses of fertilization,the author learned the growing and fertilizing regulation of cloned seedlings of Chinese fir,and came up with the scientific fetilizing methods,proper fertilizing timing and proper fertilizing doses,in the hope to provide technical reference cultivating high quality Chinese fir clones.The specific results are below:(1)At the end of growth,fertilization of Chinese fir clones promoted seedling height,and ground diameter,The seedling height and ground diameter of exponential fertilization were higher than that of conventional fertilization.Compared with the conventional fertilization,the seedling height increased by 1.7% ~3.6% and the diameter increased by 12.9%~16.6%,and the index fertilizer with 1.0 g�plant-1 was the best,which was significantly higher than the conventional fertilization treatment(P<0.05).(2)The biomass of different organs was leaf> root> stem.At the end of growth,there was no significant difference in root biomass between treatments(P>0.05).The biomass of stems,leaves and total biomass was the highest in the treatments of 1.0 g�plant-1 of nitrogen application rate,which was significantly higher than that of the other treatments(P<0.05).(3)At the end of growth,fertilization significantly promoted chlorophyll content of Chinese fir clone seedlings(P<0.05).The contents of chlorophyll a,b and total chlorophyll content were kept increase significantly in three index fertilization treatments(EF1,EF2,EF3)(P<0.05).(4)At the end of growth,the photochemical quenching,apparent electron transport rate,and quantum yield of PS?of exponential fertilization treatments were significantly higher than those in other treatments.They were increased first and then decreased and when the nitrogen application rate was 1.0 g�plant-1,the value was best.(5)At the end of growth,the nitrogen accumulation of exponential fertilization treatment was significantly higher than that conventional fertilization treatment(P<0.05),EF3 and EF2 were significantly higher than EF1(P<0.05).But the difference between EF2 and EF3 is not significant.The P and K accumulation in root and leaf and the P accumulation in plant roots were increased from exponential fertilization treatments,and the P accumulation in leaf was significantly higher than that in conventional fertilization treatment(P<0.05).The total P accumulation and K accumulation in leaves were significantly higher than conventional fertilization treatment(P<0.05).(6)At the end of growth,the Mg content of leaves was significantly decreased by applying nitrogen fertilizer,with EF2 treatment was the most significant.Compared with the conventional fertilization,the content of magnesium and magnesium in root and leaf decreased significantly,but the content of iron and accumulation increased significantly(EF2 was the best),but the content of magnesium and iron in stem was different(P<0.05).The content of iron in root and leaf was less than that in multi-and iron-accumulation,and the accumulation of Fe in single plant was the best(P<0.05).(7)The Mn content and accumulation in root significantly increased from EF3 treatment(P<0.05).The Mn content and accumulation in steam significantly increased from EF2 treatment while those in leaves were significantly decreased from EF2 and EF3 treatment(P<0.05).(8)Considering the characteristics of seedling growth,chlorophyll content,chlorophyll fluorescence,nutrient accumulation and nitrogen absorption and utilization,exponential fertilization of 1.0 g�N seedling-1 was the best method in cultivating Chinese-fir clonal seedlings under the regimes of this experiment.