Papers

Summary

– Compaction is one of the major physical phenomena that cause soil degradation and crop yield losses. Identifying through indirect techniques, fast and low cost, local and soil moisture with higher compaction potentials is an important tool for sustainable soil use. The proposal is to understand the behavior of soil compaction with different mineralogical compositions and vegetation cover, and with the use of the magnetic signature of the soil (SM) to direct the management in places and humidity that does not condition compaction. Compaction curves were constructed by the Proctor test for three soils with different iron contents, Dystrophic Red Latosol (LVd); Eutrophic Red Latosol (LVef); Dystrophic Orthodox quartzenosis (RQod). The granulometry, mineralogical composition and SM were also evaluated. For each soil type, the degree of compaction was tested in six different water contents (6, 12, 18, 24, 30 and 36%) and depth (0,0-0,1 m, 0,1 - 0,2 m; 0.2-0.3 m; 0.3-0.4 m). The effect of the vegetation cover on the physical quality of the soil considering 4, 8 and 12 t straw / ha was also evaluated. With soil water contents up to 18% when handled with the same compaction energy, soils with a magnetic signature less than 11x10-6m3 / kg1 compact up to 24% more than soils with values above 50x10-6m3 / kg1. The magnetic signature of the soil allowed the construction of specific management maps, indicating places with different susceptibilities to compaction as a function of humidity. The vegetation cover had an important role in the soil structural improvement, reducing in all soils the compaction potential. The straw damping effect reduced soil density by 23% in LVd when driven at 6% moisture and 19% at RQod at 12% moisture.