Abstract

Monitoring the physical quality of Cerrado soils under intensive sugarcane production requires sustainable forms of soil use and management. Thus, the objective of this research was to evaluate the aggregation and organic matter content in soil planted with sugarcane under different tillage systems. The experiment was conducted at the Jalles Machado Sugarcane Mill, in the city of Goianésia – Goiás State, Brazil. The statistical design was a randomized block with four replications. The following treatments were evaluated: 1. Moldboard plow + harrow (AA + G); 2. Ripper + harrow (SS + G); 3. Direct furrowing (SD); 4. Ripper + direct furrowing (SS + SD); 5. Stubble thrasher + ripper (DS + SS); 6. Stubble thrasher + harrow + moldboard plow + harrow (DS + GAAG), for the soil layers of 0-0.2; 0.2-0.4 and 0.4-0.6 m depth. The highest soil organic matter (SOM) levels, geometric mean diameter (GMD) values and distribution of aggregates between 4-2 mm were found in the 0-0.2 m layer for the SD and SS + SD treatment. There was a positive correlation between the SOM and GMD values. SD, SS + SD and DS + GAAG systems showed higher soil aggregate classes between 4-2 mm when compared to DS + SS in the 0.2-0.4 m layer. There was also an increase in the <0.25 mm class for AA + G. The AA + G + and DS + GAAG conventional systems had higher sugarcane yields, but these results were statistically similar to the conservation cropping system.

Key words: Soil management, aggregates, Brazilian Cerrado, ratoon.