Managed Land
The managed land module consists of several components: (i) Crop and grass production model (yields of food and feed crops, energy crops and grass); (ii) Nutrient management Model (nutrient requirements in relation to yields, and fertilizer use efficiency to compute fertilizer inputs and animal manure management systems) and (iii) Carbon plantations model (carbon plantations).
Nutrient Management Model, description Nutrient Management ModelIMAGE 2.4 includes the Nutrient Management Model (NMM) approaches to assess the consequences of changing population, the economy and technological development for nutrient (N and P) emissions from nonpoint (diffuse) sources. Such approaches were absent in earlier versions of IMAGE. In addition, scenarios for fertilizer use were based on economic development only, without considering agricultural production and efficiency of nutrient use. The IMAGE 2.4 calculations are spatially explicit to allow for demonstrating the large-scale and transboundary effects of local emissions that are dispursed into in the environment. These calculations are based on the surface N and P balance approach for both managed land and natural vegetation. This forms the basis for the assessing of the fate of the nutrients in the environment. Estimates for point sources are based on population densities, per capita human N emissions, and data on sanitation coverage and wastewater treatment. For nonpoint sources we use spatial information on land use, climate, hydrology, geology and soils, combined with data on N inputs (fertilizers and animal manure, biological N fixation, and atmospheric deposition) and outputs (N removal in harvested agricultural products and ammonia emissions). The surface balance can be calculated using this information. |
