Growth of the energy crop giant reed (Arundo donax L.) and optimization of the ARMIDA model in the south-central region of Buenos Aires, Argentina

The impact of fossil fuels on greenhouse gas generation has intensified the study of new renewable energy sources such as energy crops. Arundo donax L. is one of the promising crops for energy production due to its high growth rate and tolerance to different adverse conditions. This work aimed to study Arundo donax L. as an alternative for energy generation through biomass production. The second growth cycle of the crop planted in the spring of 2019 in Azul, south-central Buenos Aires - Argentina, was evaluated under potential (irrigated and fertilized) and natural conditions (without irrigation and fertilization), using two forms of reproduction and two densities. Periodically, measurements and estimates of leaf area index (LAI), solar radiation intercepted by the crop, radiation use efficiency (RUE), aboveground biomass, and other agrometeorological parameters were made. Subsequently, with the agrometeorological parameters obtained under potential conditions, the ARMIDA model was optimized under local edaphoclimatic conditions. The aboveground biomass of the crop planted under potential conditions was 41.58 t ha- 1 dry matter, 2.5 times higher than in natural conditions, and presented a maximum LAI of 6.59 and RUE of 2.16 g MJ-1. The ARMIDA model overestimated the evolution of LAI throughout the growing season, simulating a maximum LAI of 7.35. The calibrated model underestimated aboveground biomass, simulating 5.3% less than that obtained in the field. The optimization of the ARMIDA model allowed a better systematization of the knowledge about this crop in the south-central region of the province of Buenos Aires.