Response to organic and inorganic fertilization, model development and evaluation for Napier grass (Pennisetum purpureum, Schum.)

Abstract

The Napier grass model was evaluated for the tropical climatic conditions o f Santa Cruz, Bolivia. The experimental data that were used for model evaluation included two different crop management strategies related to nitrogen fertilizer application rates and cutting intervals.In general, the model showed a fairly good prediction for aboveground biomass, leaf and stem biomass and plant height. The model simulated the plant nitrogen balance fairly well and showed a strong response o f leaf and stem nitrogen concentrations to the applications o f nitrogen fertilizer following each cut.The results from this evaluation study indicate that the CSM-CROPGRO-Napier grass model has the potential for application as a research and technology transfer tool for sustainable management o f Napier grass under tropical and subtropical conditions. However, it will be necessary to continue to adjust the model to deal with some o f the differences between annual crops and forage crops, including multiple harvests.