INTERPOLAÇÃO ESPACIAL DA RESISTÊNCIA DO SOLO Á PENETRAÇÃO EM ÁREAS CULTIVADAS COM CANA DE AÇÚCAR SOB DIFERENTES CONDIÇÕES DE COLHEITA

Abstract

The Paraíba, data from Companhia Nacional de Abastecimento (Conab) show that in the last ten years the state has remained the third largest producer of sugarcane among the Northeastern states, being lower than Pernambuco and Alagoas. In the 2017/2018 harvest the area planted was 110.3 thousand hectares, with production of 5.764.26 thousand tons (ASPLAN, 2018). Dalchiavon et al. (2014) states that culture is the main raw material for the production of ethanol used as biofuel, in addition to the production of sugar, a product of important export in Brazil. In this sense, the objective of the present work was to evaluate the spatial interpolation of resistance and the penetration in sugarcane cultivated area under different harvesting conditions in the coastal trays in the state of Paraíba. The study was carried out in three areas of sugarcane production at Fazenda Santa Emília II, belonging to the Miriri and Bioenergia S / A Plant, located in the municipality of Rio Tinto and the third at Fazenda Maria da luz I, located between the municipalities of Capim, Santa Rita and Sapé, state of Paraíba. In order of soil, three areas of different conditions of use were selected: I. Harvesting manual - second cut, II. Mechanized harvesting - second cutting and harvesting III manual and mechanized. The samples were taken in plots of 100 x 100 m, under a sampling grid of 40 x 40 m, including lines and planting lines, with each crossing point of the georeferenced sample mesh, and its mechanical resistance to penetration with the aid of an impact penetrometer at the depth of 0-0.6 m, deformed and undisturbed samples were collected at depths of 0-0.1 and 0.1-0.2 m for analyzes of the following variables: Texture, Clay dispersed in water, flocculation degree, soil density and total porosity. The analyzes were carried out at the Soil Physics Laboratory, Department of Soil and Rural Engineering, Federal University of Paraíba - DSER / CCA / UFPB. The values of resistance to penetration are variable according to the depths, generally, in the subsurface layers are those that suffer with effect of the traffic of machines. The manual harvest area (CMA) presented the highest RP values among the three areas studied. Mechanical and mechanized harvesting areas (CME) followed a similar pattern, presenting low RP in the subsurface layers, with increasing values at higher depths, and RP values did not demonstrate the occurrence of compacted zones considered as impeditive to root growth . Considering the sandy texture of the studied soils, the values obtained for PR are not considered critical, that is, they do not negatively interfere in the development of the root system of the sugarcane.