EFFECT OF GROUND COVERS AND TILLAGE BETWEEN RASPBERRY ROWS ON SELECTED SOIL PHYSICAL AND CHEMICAL-PARAMETERS AND CROP RESPONSE

The use of inter-row ground covers has been suggested to reduce soil d egradation in raspberry (Rubus idaeus L.) production. The effect after 6 yr of consistent inter-row management of ground covers or roto-till age in raspberry on soil wet aggregate stability (WAS), bulk density, organic C and total N, and mineralizable nitrogen in the Fraser Valley of British Columbia was studied. Management treatments included no co ver crop or cover crops of barley (Hordeum vulgare L.), sheep's fescue (Festuca ovina L.), perennial ryegrass (Lolium perenne L.), and white clover (Trifolium repens L.). A general pattern of perennial grasses > legume arid barley > control was observed for soil WAS. Some quantit ative and qualitative differences in the organic component of the soil profile to 30 cm were detected among management treatments. The diffe rences were not statistically strong because the changes were small re lative to the large pool present, but were relatively consistent overa ll. The white clover treatment tended to have more organic carbon, par ticularly in the subsurface, than the other treatments. The four treat ments that included inter-row vegetation tended to have a greater amou nt of total and mineralizable N than the clean-tilled control. Crop vi gour, as indicated by cane diameter, was reduced by the perennial gras ses, but the inter-row management had only limited effects on berry yi eld. White clover appears to provide the best compromise between impro ving soil quality and minimizing competition with the berry crop.