Eucalyptus harvesting, forwarding and soil till-age operations are among the main causes for compaction of forest soils, with potential impacts on productivity. This concern is especially important in areas with soils that are naturally compacted (fragipans and duripans). In these soils, tillage operations include the use of subsoilers that can reach depths of more than one meter and require heavy tractors that exert high pressure on the soil. One of the ways to try to minimize the effect of this compaction is by retaining harvest residues. The objective of this study was to evalu-ate the impacts of eucalyptus harvesting on soil physical attributes, as well as to determine the potential of different types of residue management to reduce compaction from the soil tillage operation. Two experiments were conducted in the same area with a Yellow Argisol. In the first experi-ment, compaction caused by mechanized harvesting with harvester + forwarder was evaluated. In the second experi-ment, different managements of harvest residues were exam-ined as potential modifiers of soil compaction during tillage for new plantings. For this, three managements systems were tested: (1) retention of all harvest residues and litter from the previous rotation (HR + L), (2) retention of litter from the previous rotation (L), and (3) removal of harvest residues and litter from the previous rotation (WR). Before and after harvest, sampling was carried out in the planting rows and inter-rows, and after tillage, samples were collected in the traffic line of the subsoiler-tractor set. In both experiments, undisturbed soil samples were collected from the center of the 0–10, 10–20, 20–40, 40–60, and 60–100 cm layers to determine soil density and total porosity. In each period and site of evaluation, mechanical resistance to penetration up to the 60-cm depth was also determined. The harvest-ing operation increased soil density at 0–10 and 60–100 cm depths only in the inter-rows. Retention of harvest residues and litter (HR + L) after harvesting avoided increases in soil density and penetration resistance caused by machine traffic during tillage. The results indicate the importance of retain-ing harvest residues on forest soils for achieving sustainable utilization and for conserving soil quality.

Soil Science Department,Universidade Federal de Vi?osa, Vi?osa,Minas Gerais,Brazil;BRACELL Company,Alagoinhas,Bahia,Brazil

[1]Raphael Oliveira de Melo;AymbiréAngeletti da Fonseca;Nairam Félix de Barros;Raphael Bragan?a Alves Fernandes;Rafael da Silva Teixeira;Iago Nery Melo;Ricardo Previdente Martins-.Retention of eucalyptus harvest residues reduces soil compaction caused by deep subsoiling)[J].林业研究（英文版）,2022(02):643-651

subsoiling,fragipans,duripans,subsoilers,tractors,Argisol,forwarder,plantings,subsoiler

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