NRate.farm — Smart Nitrogen Calculator for Farmers
German farmers applying nitrogen fertilizer face a compound decision problem: agronomic yield targets, volatile input costs, real-time grain prices, and mandatory DüV (Düngeverordnung) regulatory constraints must all be reconciled simultaneously. Existing tools either ignore economics (yield-only models) or ignore regulations (simple calculators). No publicly available, free tool combined marginal revenue analysis with DüV compliance, regional soil/climate data, and multi-crop support in one production-ready interface — leaving farmers to make high-stakes fertilization decisions with incomplete information.