Understanding the characteristics and properties of the soils of the state of Rio Grande do Sul low lands, which are being used now with the culture of irrigated rice, is indispensable for the adoption of practices involving irrigation, drainage, correction of acidity and fertility. Mainly when high productivity levels are desired with lower cost and with fewer possibilities of soil and air degradation. The objective of this work was to evaluate compaction of a Planossolo cultivated under different handling systems through the technique of mechanical resistance of the soil to penetration. The occurrence of compacted layers was identified, in the intermediary depth (0.10-0.20 m) in the systems with larger use of agricultural mechanization (T2 - Continuous rice cultivation system and T3 - rice x crop rotation cultivation system). An increase of the values of the soil's mechanical resistance to penetration was observed in relation to the control in all the systems (T6 - Soil without cultivation), mainly in the intermediary layer (0.10-0.20 m), when the soil was submitted to the continuous rice cultivation system (T2). The treatments T3 (rice x crop rotation) and T5 (succession of cultures: soybean (conventional system) x rice (zero tillage)) showed the highest values of resistance to penetration, probably due to low humidity and to the cultivation effects and the use of machines, causing deformation of the soil structure.
soil resistance mechanics; crop tillage systems; soil compaction; albaqualf