Principles of nutrient management for sustainable forest bioenergy production

Nutrient management is an important part of ensuring sustainable forest production. Essential concepts for managing site nutrients are built on the knowledge of types of soil, tree nutrient demands, and how these are impacted by silviculture, harvesting, and other management practices. Managers must clearly define forest management objectives, and how bioenergy production or carbon dioxide-offset objectives require special consideration. Managers must examine how silviculture, harvesting, and other management practices might affect nutrient pools and availability. Soil fertility management practices are designed in response to these evaluation steps. Fertility management alternatives may include altering management practices that affect the distribution of harvested tree branches, foliage, and tops, as well as addition of fertilizers, nitrogen-fixing plants, or wood ash. Planting on sites with pre-existing nutrient deficiencies may require adding nutrients to obtain merchantable tree growth over the short and long term. Nutrient management principles may also be required to minimize off-site impacts of management practices, for example, on water quality or climate change. Managers must determine what nutrients are needed on forested sites, amendment rates, and timing, and take into account the relationships among nutrients, soil, climate, and plant processes throughout the rotation. Soil and foliar analysis and the use of soil and plant bioassay tools can assist in these evaluations. Sustainable management practices require that nutrient control strategies evaluate economic and energy balances, and if necessary, modify management practices, including nutrient amendments, to ensure that they are sustainable. Examples of forest nutrient management practices are described. (C) 2012 John Wiley & Sons, Ltd.