Ⅰ-69杨人工林生长规律与营养特性的研究

1982年以来在湖南省汉寿进行了Ⅰ-69杨人工林生长规律与营养特性的定位研究。前三年(1982～1984年)结果表明,当地的气候、土壤生态因子适于Ⅰ-69杨生长,胸径生长年、月变异极显著。第一年生长慢,8月为高峰期;第三年较第二年次之,6月为高峰期。三年胸径年平均增长4.78 cm。主要营养元素(除Mg外)的月变异极显著,与胸径生长规律一致。年变化无显著差异,年平均含量较高,N为3.25％～3.31％,P_2O_5为0.58％～0.59％,K_2O为1.59％～1.61％,CaO为3.17％～3.28％,MgO为0.54％～0.70％,反映了Ⅰ-69杨生长与主要营养元素吸收、利用以及土壤养分的供给,处于动态平衡的良好状态。

Research on the Growth Pattern and Nutrient Characteristics in the Plantation of Populus deltoides

The investigation on the growth pattern and nutrient characteristics of Populus deltoides cv. "LUX" I-69 was initiated in 1982 in Han-shou County, Hunan Province. The results in the first three years (1982~ 1984) indicated that the local climate and soil was suitable for the growth of P. deltoides cv. "LUX" I-69. But there was significant difference in the growth of diameter breast-height (D.B.H.) among different years and different months. The growth of D.B.H. was slow in the first year with a peak in August. But the growth peak in the second year and third year was in June. The average growth in D.B.H. was 5.04cm annually. The contents of the major nutrient elements in the plants varied significantly with different months except Mg2+, but had no significant variation among different years. The variation pattern of nutrient contents within a year was similar to the D.B.H. growth pattern. The following are the annual average contents of some major nutrients: N:3.25%~3.31%, P2O5: 0.58 %~ 0.59%, K2O:1.59 %~1.61 %, CaO: 3.17 %~3.28 %, MgO:0.54 %~0.70%. This showed that the plants had a high nutrient level and a good condition including the soil nutrients supply, absorption and utilization existed in the tested plantations for the tree's growth.