Main content area

New APSIM-Sugar features and parameters required to account for high sugarcane yields in tropical environments

Dias, Henrique Boriolo, Inman-Bamber, Geoff, Bermejo, Rodrigo, Sentelhas, Paulo Cesar, Christodoulou, Diomedes
Field crops research 2019
canopy, climate change, crop yield, data collection, genotype, harvest date, irrigation, nutrients, planting date, simulation models, sugarcane, temperature, Brazil
Sugarcane in field plot experiments in tropical Brazil (Guadalupe, Piauí State, 6.6°S), produced very high yields under non-limiting water and nutrients. Mean stalk dry mass at 8, 11.5 and 15 months was 40, 51 and 70t/ha respectively for six varieties and six planting dates. These yields were explained by high but not excessive temperatures allowing the canopy to close after 73 days on average. Substantial changes were required to enable the APSIM-Sugar model to simulate canopy and yield gain processes in Brazilian genotypes for the purpose of optimising variety, planting and harvest date options. A new modelling feature was proposed to deal with the observed growth slowdown when crop was about seven/eight months old and dry mass yields higher than 40t/ha. All new parameters and features were validated with independent experiments as well as with the original dataset used for developing APSIM-Sugar. Future studies involving irrigation, yield gap analysis and climate change in environments where high yields are expected, should consider these modifications.