Effects of Fertilizer Nitrogen on Tree Growth, Foliar Nitrogen, and Herbage in Eastern Cottonwood Plantations
1977
Blackmon, B. G.
When five rates of nitrogen fertilizer (0 to 672 kg/ha) were tested in two eastern cottonwood (Populus deltoides Bartr.) plantations 7 and 10 years old in the Mississippi River floodplain, first season volume growth was more than doubled by fertilization. By the end of the third season, the direct effect of fertilization had apparently disappeared although a volume advantage caused by the large initial response was still evident. In one plantation, volume growth for the 3 years after fertilization was greatest at 336 kg N/ha, and in the other volume growth was greatest at 672 kg N/ha. However, lower rates gave more volume growth per unit of applied N. Fertilizer also increased the N content of herbaceous plants.
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