The biggest disadvantage of nitrogen fertilization is the excessive promotion of vegetative growth , surpassing the reproductive phase of the trees, in addition to triggering the succulence of the trees to unprecedented attack of insectpests....
What type of forest do you mean? Pristine or primary forest do not need additional N. However, these forests receive additional N inputs (...combustion of fossil fuels) due to atmospheric deposition, which induces species shift and accelerates decomposition of soil organic matter. Any managed forest/plantation may require N fertilization due to short rotation systems or intensive production of commodities (e.g palm oil). However, systems mixed with legumes may require less additional N. Best Nils