Soil water content and management systems can promote changes in compressibility parameters. The objective of this research was to study the effects that water content and sugarcane management systems have on the compaction degree and compressibility parameters of a cohesive Yellow Argisol. Four sites were selected in the surroundings of the sugar mill Triunfo, in the state of Alagoas, Brazil; one site with irrigation and a second without irrigation, a third with vinasse application and a fourth under native forest, taken as representative of the original soil condition. Samples from each site were collected at 0-0.2, 0.2-0.4 and 0.4-0.8 m depths and at 0-0.2 and 0.2-0.4 m, to determine alterations in the soil compaction and compressibility parameters, respectively. Management systems with and without irrigation increased the degree of soil compaction and resistance of aggregates to rupture as compared to those of the soil under native forest, resulting in an increase in the soil load support capacity. The increases in the soil water content reduced precompaction pressure and enhanced the compression index, resulting in a lower soil load support capacity.
precompaction pressure; compression index; aggregate rupture strength; sugarcane; coastal plain
