Development approach and evaluation of the Nutrient Expert software for nutrient management in cereal crops

Meeting the demand for more food in the next 20–30 years requires intensifying cereal cropping systems and increasing current yields to about 70–80% of the genetic yield potential. A dynamic and robust nutrient management approach such as site-specific nutrient management (SSNM) will be essential to increase yields and optimize profits while maintaining the productivity of these intensive cropping systems. SSNM has increased yield and profit in rice, maize, and wheat in major cropping systems in Asia; but, crop advisors have found it complex and difficult to implement in the field. Nutrient Expert (NE) was developed to provide crop advisors with a simpler and faster way to use SSNM. NE enables crop advisors to develop SSNM recommendations using existing site information. Nutrient Expert for Hybrid Maize (NEHM) increased yield and profit of farmers in Indonesia and the Philippines. In Indonesia, NEHM increased yield by 0.9 t ha−1, which increased profit by US$ 270 ha−1 over farmer’s fertilizer practice (FFP). Compared with FFP, NEHM recommendations reduced fertilizer P (−4 kg ha−1), increased fertilizer K (+11 kg ha−1), and did not significantly change fertilizer N. In the Philippines, NEHM increased yield by 1.6 t ha−1 and profit by US$ 379 ha−1 compared with FFP. Compared with FFP, NEHM gave higher rates of all three nutrients (+25 kg N ha−1, +4 kg P ha−1, and +11 kg K ha−1), which substantially increased fertilizer costs (US$ 64 ha−1) but still increased profit by about six times the additional investment in fertilizer. NE accounts for the important factors affecting site-specific recommendations, which makes it a suitable starting point for developing nutrient management tools to reach more users.

• Nutrient Expert uses the principles of site-specific nutrient management (SSNM).
• NE enables the development of SSNM recommendations using site information.
• NE recommendations can increase yields and profits of farmers.
• NE is a suitable starting point for developing other nutrient management tools.