THE STUDY ON THE GROWTH AND NUTRIENT DISTRIBUTION OF THE POPULUS DELTOIDES CV. “LUX” I-69

The study on the growth and nutrient distribution of Populus deltcides cv. "LUX" I-69 in Hanshou County, Hunan Province shows: In the same conditions, the significant differences are found in the growth of grade I seedlings is 1.4~1.7 times that of grade Ⅱ or Ⅲ. The annual root stem growth of grade I is 1.3~1.6 times that of grade Ⅱ or Ⅲ. The biomass accumulation of high-grade seedlings is 40 times more than the poor one. The biomass (dry weight) accumulation is about 2400 kg per mu (1/15 hectare). In the same conditions, the accumulation of main nutrient of different grade seedlings is also different: Grade I is 2.2~4.3 times that of grade Ⅱ or Ⅲ. The accumulation of main nutrient is 148 kg per mu. The proportion of Ca:K:N:P:Mg is 6.0:5.5:4.0:1.5:1.0.The content of nutrient distribution varies with different parts within a seedling. The nutrient content of the leaves and the roots are much more than that of the stems and the cuttings. The nutrient elements distribution in the different parts varies too. The greatest content of N is in the leaves while the greatest content of K exists in the leafstalks and the greatest content of Ca exists in the roots.