Zoneamento do potencial de pastejo do Capim- Sudão BRS Estribo com base na espacialização de soma térmica na Região Sul do Brasil

Abstract

Based on a partnership between Embrapa and Sulpasto, an annual summer forage species was developed, called sudangrass BRS Estribo, where BRS is the name given to all cultivars developed by Embrapa, and Estribo is the name chosen by the developers of the genetic material. Due to its recent origin, this plant still needs information that relates its production to agroclimatic parameters such as air temperature and thermal sum. Therefore, the present study aimed to estimate the potential for the availability of thermal sum for the cultivation of the sudangrass BRS Estribo, through the process of spatialization of agroclimatic data in the South Region of Brazil, and thereby verify the grazing potential, considering grazing occurs when the plant reaches between 50 and 60 cm in height, and the animals remain until the lowering of the pasture, between 10 and 15 cm in height. In the work methodology, Machine Learning techniques were used for the spatialization of temperature data, operating databases with resources from Geographic Information Systems (GIS). Altimetric data in matrix format from SRTM (Shuttle Radar Topography Mission) with spatial resolution of 90 meters and monthly temperature averages compiled over a period of thirty years were used. The temperature spatialization was done with regression models, calculated monthly in relation to altitude, latitude and longitude. More specifically, trend interpolation is used to adjust the Earth’s surface data and the ordinary square limit method to determine the regression coefficients of the linear regression equations. From the regression models, maps of average monthly temperature and thermal sum were generated for all months of the year. Finally, the maps of the thermal sums related to the production period of the sudangrass BRS Estribo, which it provides between the months of October to April, were generated, as well as the simulation of the number of possible grazing in the region. As a result, it was found that in the period used for planting, the number of grazing in the period considered ideal for production ranged from 1 to 12, with better results being obtained in the northwest of Rio Grande do Sul and northern Paraná, and more cold, which to a large extent have higher altitudes, has a lower production.