Effect of Soil Compaction Caused by Manual and Mechanized Harvesting Management on Sugarcane Yield
摘要
Brazil is the world's largest producer of sugarcane, and mechanized management has increased the crop's productive efficiency. However, the intensity of machine traffic causes soil compaction, limiting the increase in productivity and longevity of crops. The harvesting operation compacts the soil as heavy machines move over the ground in inadequate moist conditions. This study evaluated soil compaction and sugarcane productivity in different productive areas with manual and mechanized harvesting practices over four years of harvest. Samples of soil resistance to penetration were taken after planting, harvesting, and from harvesting rows and between rows. The data were subjected to statistical analysis and Pearson's coefficient determination for soil penetration resistance and productivity variables over time. Resistance to soil penetration was observed in agricultural areas, regardless of management practices, with machinery primarily affecting the surface soil layers (0 to 0.3 m). The mechanized system, in the first year of the harvest, increased resistance to soil penetration by 270%, compared to 75% in the manual method. Manual harvesting management presented a cone index similar to a mechanized harvesting system, with a 14% increase in resistance to soil penetration. No significant differences in compaction were found between areas with manual and mechanized management at depths above 0.3 m. Productivity decreased linearly with cultivation time for both harvesting methods (r2 0.90 and 0.97—manual and mechanized), indicating that, independent of the harvesting model, sugarcane productivity tends to stabilize after the fourth year of production.