LINTUL-Cassava-NPK: A simulation model for nutrient-limited cassava growth

Area of Science:

• Agricultural Science
• Crop Physiology
• Soil Science

Background:

• Understanding plant nutrient dynamics is crucial for effective fertilizer management and nutrient use efficiency.
• Cassava (Manihot esculenta) yield is significantly impacted by nutrient availability, particularly nitrogen (N), phosphorus (P), and potassium (K).

Purpose of the Study:

• To develop and validate the LINTUL-Cassava-NPK crop model for simulating cassava biomass growth and yield under nutrient-limited conditions.
• To assess the model's ability to capture nutrient uptake dynamics and interactions of N, P, and K.

Main Methods:

• Utilized experimental data from six Nigerian fields across three agro-ecologies over two growing seasons (2016-2018).
• Implemented nutrient stress by combining N, P, and K nutrition indices (NI) to simulate multiple nutrient limitations.
• Parameterized and calibrated the model using optimal condition data, then tested with nutrient-limited experimental data.

Main Results:

• The model accurately simulated N, P, and K uptake patterns, with small root mean squared errors.
• Predicted storage root yield with high accuracy (R² of 0.7-0.8).
• The model effectively simulated yield responses to nutrient omissions and varying NPK application rates.

Conclusions:

• The LINTUL-Cassava-NPK model provides a robust tool for understanding nutrient limitations and NPK interactions in cassava.
• Findings highlight the importance of balancing N and K supply for optimal cassava growth and yield.
• This is the first tested process-based cassava model incorporating three essential macronutrients.