Effects of tillage and management practices on soil crust morphology undera Mediterranean environment

Soil crust formation can be affected by soil tillage. Alternative soil cons ervation practices consisting of reduced tillage were tested against tradit ional tillage, which involves mechanical weeding by frequent ploughing in r ainfed vineyard soils in Catalonia, Spain. After 2 years of the experiment (1994-1996), thin sections of the surface crusts were studied to evaluate t he effects of the soil management treatments on crust morphology and genesi s, using micromorphological observations and pore characterisation with ima ge analysis. Reduced tillage caused thicker and more complex crusts consist ing of layers with different degrees of sorting and pore types, compared to traditional tillage. Total porosity of crusts did not differ from that of non-crusted areas, but pores in crusts were less interconnected, more horiz ontally distributed and more elongated than in the underlying non-crusted m aterial. The soil type, especially structure and texture, affected crust mo rphology and played an important role in the process of crusting. The resul ts show that reduced tillage may be limited as an alternative management pr actice when used to reduce crust formation in Mediterranean conditions, due to the difficulty to establish an effective groundcover. (C) 2000 Elsevier Science B.V. All rights reserved.