License Agreement

Maize-N is a computer program that simulates fertilizer requirement for Maize crop grown under intensive management.

• Assess the overall site yield potential and its variability based on historical weather data.
• Evaluate attainable yield, N uptake, and fertilizer N required based on climatic and management factors such as planting date, hybrid maturity, and plant density, N application method and timing, manuring, and soil characteristics.

The estimation of N fertilizer requirement in Maize-N is based on user input information on the current maize crop, last season crop, tillage and crop residue management, basic soil properties, fertilizer management and manuring, and long-term weather data of the field. The program first simulates maize yield potential (i.e., maximum yield with optimal water and nutrient supply and without stresses from diseases, insects and pests) and its year to year variation. It then simulates mineral N released from mineralization of soil organic matter, crop residues (roots and straw or stover) and manures. The program can also estimate recovery efficiency of applied N fertilizers. Finally, it estimates the economically optimal N rate (EONR) of fertilizer for the current maize crop.