| The experiment was conducted in Root System Laboratory, College of Horticulture, Shandong Agriculture University during 2001-2003. Effects of organic materials and N fertilizer on biomass, dry matter distribution, root respiration and hurt of N stress were analyzed. Potted and solution cultured one-year-old Mains hupehensis Rehd. seedlings were used as materials. The main results are as follows:1. 100 and 200 mg kg-1N fertilizer could improve growth indexes, and fertilization level showed significant positive correlation with growth indexes. For functional leaves, appropriate N fertilizer could increase dry mass, leaf area and preventing from premature senescence. At the initial stage, dry mass and leaf area of 200 mg kg-1 N fertilizer were 1.83 and 1.51 times these of control's, and 1.26 and 1.14 times in late stage respectively. The chlorophyll content of it was 1.47 times that of control's in later stage. N fertilizer improved dry mass of stem, leaves and height significantly, which increased 1.82, 1.89 and 1.39 times those of control's respectively in later stage. Root DW of 100 and 200 mg. kg-1N fertilizer also increased, and it was 1.29 and 1.63 times those of control's respectively in late stage. The effects of N fertilization on growing root was most obvious, and growing root of 100 and 200 mg kg-1 N fertilizer increased 1.67 and 2.56 times in May, and 1.08, 1.31 times in Oct respectively. Excessive N fertilizer was harmful to plant. Functional leaf area was too large in 500 mg kg-1 N fertilizer, which resulted in falling of SLW and produced negative effects on quality of leaves. Growth of absorbing root was restrained in 500 mg kg-1 N fertilizer, with a increase of 5% compared with control.2. Growth and development, dry mass of seedlings increased gradually with organic materials fertilizer application. For functional leaves, leaf dry weight was most affected by organic materials, leaf DW of fertilizer with 3% and 6% organic materials increased by 26%, 48% in May, and by 39%, 60% in Oct compared with control respectively. Compared with control, the stem DW increased significantly by 143%, 22.9% in fertilizer with 3% and 6% organic materials in May, and by 128%, 186% in Oct. Also organic materials promoted root growth, compared with control, DW of fertilizer with 3% and 6%organic materials increased by 34%, 65% respectively at the beginning of fertilization, and by 29%, 36% during laterperiod. Of the three kinds of roots mentioned above, absorbing roots were affected most, fertilizer with 3% and 6%organic materials increased by 133%, 267% in May, and 120%, 140% in Oct.3. The combined application of organic materials and N fertilizer had a evident effect, all growth indexes increased with increase of fertilization level and offseted the negative effects of 500mg kg-1 N fertilization. Of all the treatments, 6% organic materials + 500mg kg-1 N fertilizer showed the best effects in increasing plant biomass. Compared with control, leaf DW, leaf area, SLW, chlorophyll content in functional leaves of 6% organic materials + 500mg kg-1 N fertilizer all increased by 152%, 87%,35%,58% respectively during the early stage, and by 98%,56%,27%,75% during the late stage respectively. Total leaf weight, leaf area, stem diameter, shoot weight and the plant height were 4.13,1.78,1.37, 5.36 and 2.16 times those of control during late period, and 2.43,2.66,1.43,3.69 and 1.79 times those of control during early period.4. Fertilization affected dry matter distribution among different organs. The organic materials and N fertilizer application decreased the ratio of dry matter distribution in ligneous roots and increased in fine roots. Fertilization had more significant effect on fine roots than on ligneous roots, while N fertilizer affect more apparently on growing roots and organic materials on absorbing roots.5. The N and organic materials could affect the dry matter distribution in different organs with the increase in leaf and a decrease in ligneous roots. The effects of fertilization on dry matter dis...
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