Variation of soil penetration resistance as a function of soil moisture under crop management systems
Keywords:
Manejo e Conservação de Água e SoloAbstract
The objective of this work was to monitor the temporal variation of penetration resistance (PR) after soil saturation under different management systems in the Cerrado biome in three areas: two in no-tillage systems (NT with 3 and 10 years of implantation) and one of crop-livestock integration (CL with 9 years of implantation) with soybean/forage succession. Four transects were delimited in each area. The delimited area was saturated and the PR measurements were performed daily for 11 days at 10 points of the transect, and up to 0.40 m of depth. Soil moisture was determined together with PR measurements, in addition to soil hydraulic conductivity and organic carbon. PR values were more significant in the 0.10-0.20 m layer than in the 0.0-0.10 and 0.20-0.40 m layers. The NT-3 area showed a lower PR value (1.65 MPa) than the area under NT-10 and CL-9, with 2.48 and 2.69 MPa, respectively. Thus, it was possible to determine critical soil moisture values, that is, soil moisture values most susceptible to soil compaction. Thus, in the NT-3 area, the critical humidity was 0.20 kg kg−1, in the NT-10, ranging from 0.19–0.20 kg kg−1, and in the ILP-9, between 0.23– 0.20 kg kg−1. By monitoring soil moisture, it is possible to prevent management operations from restricting root growth.
