SHORT-TERM EFFECTS OF COVER CROP INCLUSION UNDER NO-TILLAGE MANAGEMENT ON SOIL PHYSICAL QUALITY

Effects of cover crop on soil physical quality

Resumo

Integrating cover crops in the crop sequence could lead to an enhancement of the no-tillage (NT) performance improving soil physical quality (SPQ). The objective of this work was to follow the evolution of SPQ and soil water content during the first year of cover cropping management, as compared with bare fallow. SPQ indicators were determined from the soil water retention curve (SWRC) and in-situ infiltration data in different dates during the first year after inclusion of cover crop. The experiment was carried out in a fine, illitic, thermic abruptic Argiudoll. Two management systems were evaluated: a) no-tillage with bare fallow (BF), b) no-tillage with cover crop during the fallow (barley and vetch) (CC). For both treatments, maize was sown as summer crop. The differences between management systems were observed during the maize growing period. CC management showed higher values of field capacity (FC), plant available water content (PAWC) and Dexter index (S), and lower values of bulk density (BD) as compared with BF, showing that the inclusion of cover crop under NT management improves the soil capacity to retain water and counteract compaction processes under NT. At the end of the crop cycle, higher values of water-conducting macroporosity (ε_ma) and macropore connectivity (Cw_ma) were observed under CC. Higher values of soil water content during the maize growing period were observed under CC, showing that the inclusion of cover crop has no negative effects on the top soil water content. Our results show that the inclusion of cover crop is an opportunity for intensify crop sequences in the Argentinean Pampas Region, oriented to enhance the performance of NT.