Tree Nutrition and Forest Fertilization of Pine Plantations in the Southern United States

摘要: The growth of many pine plantations in the southern United States is limited by soil nutrient availability. Therefore, forest fertilization a common silvicultural practice throughout South. Approximately 1.2 million ac were fertilized 2004. In last 10 years, considerable advances have been made identifying ecophysiological basis for stand and response to fertilizer additions. Nitrogen (N) phosphorus (P) are nutrients that most commonly limit pine. On wet clay soils lower Coastal Plain on some well-drained upper Plain, severe P deficiencies exist. these soils, with 25–50 lb per acre at time planting produces large sustained response, order 50 ft 1 yr (1.5 tn ) rotation. other South, chronic both N sites, availability often adequate early rotation when tree demand small. However, around crown closure, frequently become limiting. Fertilization intermediate aged stands typically increases 8 –10 years. combination 25 plus 200 averages 55 (1.6 an 8-year period. amount leaf area main factor determining current rate potential after fertilization. When index less than 3.5, light capture restricted negatively affected. stands, will increase because increased thus growth. financial return depends occurs, cost treatment, stumpage value timber produced. Using over $90 , values from first quarter 2006, internal midrotation loblolly plantation would be approximately 16%.