Abstract
Slash pine may absorb nutrients and water best in spring and early summer because soil moisture, soil aeration, and temperature are apparently optimum at this time. One-year-old slash pine seedlings maintained at a high oxygen level grew about 1% times as many roots as were produced at a low oxygen level. No other environmental conditions significantly influenced root growth during the 12-day test period. High oxygen level plant roots had long silvery-white tips, which L graded gradually to cream, tan, and finally light brown near the base of the root segments. In contrast, new roots of low oxygen level plants were brown or tan to within a few centimeters of their tips. At 22° C, low oxygen level plants absorbed 21 percent less water, 53 percent less phosphorus, and 54 percent less magnesium at the end than at the beginning of the It-day observation period. In contrast, high oxygen level plants absorbed 9 percent more water, 61 percent more phosphorus, 22 percent more potassium, and 117 percent more magnesium daily at the end than at the beginning of the 12 days. At the low oxygen level, the 22° C seedlings calcium absorption increased 152 percent by the second day butodeclined thereafter. Trends were about the same at 16° C and 28° C, but most differences increased with increasing temperature. To maintain good growth rates slash pines may require more nutrients in inadequately drained and aerated soils than in well drained soils. Fertilization can possibly substitute for drainage on some sites because poor root aeration may reduce the plant's ability to absorb water and nutrients.
Keywords
Pinus elliottii,
temperature,
light intensity,
root aeration,
solution culture,
pine nutrition,
absorption of water,
phosphorus,
potassium,
calcium,
and magnesium
Citation
Shoulders, Eugene. 1976. Poor Aeration Curtails Slash Pine Root Growth and Nutrient Uptake. Res. Note SO-218. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station. 5 p.
