| A plot experiment was conducted with three treatments including N 50kg/hm2, N 66kg/hm2, and two different ureas, slow-release urea and common urea were used on the level of N 50kg/hm2. The experiment set up three treatments:optimized fertilization (OF), farmers'fertilization practice (FFP) and high yield fertilization (HY). The ratio of NPK for each treatments'is different. The population quality index of soybean LAI, light transmittance, dry matter weight of leaves, stems, pods and grains were determined, the grain-leaf ratio, SLW, seed-stem ratio and LAD were calculatied.1. At R2-R4, the LSD in whole and top canopy shows that HY>FFP>OF, but the LSD of middle canopy is opposite. At R4-R6 and R6-the 5 d after R6, the LSD of every canopy is OF> FFP>HY. The result showed that the very significantly positive correlations between yield and LSD at R4-R6 in every canopy and R6-the 5 d after R6 in whole and top canopy, the significantly positive correlations between the LSD of top canopy and yield at R6-the 5 d after R6.The NAR of every canopy had been obviously improved by OF treatment at R2-R4 stage. AT stage of R4-R6, the NAR in whole and middle-bottom canopy was obviously improved by OF treatment. The production efficiency of leave which in every canopy of R2-R4 and middle-bottom canopy of R4-R6 was improved by OF treatment.2. At R4, the SLW showed that HY>OF>FFP in every canopy. At R6 and 5 d after R6 the SLW is OF>FFP>HY in top canopy, it could increase the photosynthetic product of top canopy. The SLW in the middle and whole canopy is FFP>OF>HY.3. The smallest light transmittance in three step of canopy is OF. It can increase the light energy utilization behind R6 stage and yield of soybean.4. The LAI was HY>FFP>OF before the stage of R2. Every treatments at the stage of R4 reached the highest value of LAI. After R4 stage the LAI value of OF is the highest. The result of whole, top and middle canopy is OF>FFP>HY. At R6 stage, in the LAI of whole canopy there is the comparison that the OF higher than the HY, increased by 20.8%(P<0.05), and in the LAI of top canopy the OF is significantly higher than HY. The very significantly positive correlations between yield and LAI of top and middle canopy at R6 stage and LAI of middle canopy at the 5 d after R6 stage, there are significantly positive correlations between yield and LAI of top canopy at the 5 d after R6.5. At R6, the grain-leaf ratio showed that OF>FFP>HY in the whole and middle canopy, the top canopy is FFP>OF>HY. At the 5 d after R6 is HY>FFP>OF in middle and whole canopy, the top canopy's result is OF>HY>FFP, and in top canopy the OF is obviously higher than FFP. At R6, the result showed that the very significantly positive correlations between the yield and grain-leaf ratio in the whole and middle canopy, at the 5 d after R6, there are the significantly negative correlations between the grain-leaf ratio and yield in the whole and middle canopy.6. The whole canopy's dry matter weight of urea of HY is highest before R2, and after R6 the whole canopy's dry matter weight is OF>FFP>HY. After R6, the dry matter weight in every canopy were increased by OF. The OF increased the dry matter weight both of the leave in whole canopy at R2-R4 and the dry matter weight of leave in top canopy at the 5 d after R6. The OF increased the dry matter weight of pods after R4, the result of dry matter weight of pods in middle canopy showed that OF>FFP>HY. At R6, the dry matter weight of pods in top and middle canopy is OF>FFP>HY.7. The yield's result showed that OF>FFP>HY, compared with FFP and HY the yield of OF increased by 10.26% and 25.47%(P<0.05). |
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