Soil porosity and density in sugarcane cultivation under different tillage systems

Abstract

Monitoring the physical quality of soils under intensive sugarcane production requires sustainable forms of use and soil management. Thus, the objective of this research was to evaluate the influence of soil tillage systems on soil porosity and density in ratoon-cane cultivation, in addition to possible changes which may occur during the season. The experiment was carried out in the state of Goiás, Brazil. The Experimental design was randomized blocks with four replications. The following tillage systems were evaluated: 1. Moldboard plow + Harrow; 2. Subsoiler + Harrow; 3. Direct planting; 4. Subsoiler + Direct planting; 5. Stubble thrasher + Subsoiler; 6. Stubble thrasher + Harrow + Moldboard plow + Harrow, in soil layers 0-0.2; 0.2-0.4 and 0.4-0.6 m. Regardless of the tillage system used during sugarcane cultivation, the ratoon crop showed reduced total soil pore volume and macroporosity, as well as increased soil density in the 0.4-0.6 m layer. However, the use of direct planting resulted in +higher ​​soil macroporosity values in the 0-0.2 m layer and yields similar to conventional systems which use the moldboard plow. Therefore, it is recommended for producers to adopt conservation soil tillage systems, combining productivity and soil quality.   Key words: Soil management, ratoon-cane, soil compaction, conservation system.