Produtividade de cultivar de cana-energia pelo modelo DSSAT/CANEGRO

Abstract

The search for new agricultural crops geared to power generation has rekindled the interest in energy cane. A crop that has its synthesis through the genetic improvement of wild species with commercial hybrids of sugarcane, obtaining a cane with high production of biomass. Therefore, it is of the utmost importance that new research be carried out with cane-energy, for a better management of the crop. The mathematical models of predictions are excellent support tools in the implantation of energy cane in new environments, currently the DSSAT / CANEGRO model and the most used for simulation of growth of sugarcane. DSSAT / CANEGRO originated in South Africa, was based on the Ceres-Maize model and belongs to the DSSAT platform and is updated in version 4.5. The objective of this work was the evaluation and calibration of the DSSAT / CANEGRO model, with its use adjusted to assess the impact of climate projections on the productivity of fresh and dry sugarcane matter in the state of Alagoas in the present scenario and four future scenarios of RCPs (2.6, 4.5, 6.0 and 8.5). For the calibration process, the cane-energy vertix 2 variety was used in the irrigated cane cycle in a field experiment developed at Rocheira farm, Teotônio Vilela-AL municipality (09 ° 55'35 "S, 36 ° 17'03 "W; 124 m) in an area of approximately 1.0 ha (ha). The DESSAT / CANEGRO model presented a high degree of adjustment in the simulation, growth and productivity of sugarcane. The performance indicators of the model were the statistical indices: (d) Willmott, RMSE, R², Pearson's correlation (r). For the green matter variable the VERTIX 2 genotype obtained values of (0.98 and 0.94) for the indexes der, respectively, and had similar statistical indicators for the dry matter variables (d = 0.99 and r = 0.88) and height of the stem (d = 0.99 and = 0.98). The DSSAT / CANEGRO model presented a high degree of adjustment for the cane-energy genotype variables analyzed. The assessment of future scenarios was performed for a climatic series from 2018 to 2095 and the present series from 1961 to 1990, these meteorological data were acquired from the global climate model MIROC-05. Regarding productivity in general, the four CPRs obtained increases in green and dry matter in relation to the present scenario, especially CPRs 2.6 and 8.5, this increment may be due to increases in solar radiation, rainfall pluvial maximum and minimum temperature for years futures.