| Direct drilling has often been reported to increase density and strength and to affect pore continuity and tortuosity of the upper soil layers. In this study these aspects were studied for three texturally differing soils 4–6 years after initiation of continuous trials with direct drilling and mouldboard ploughing. The soils studied were a coarse sandy soil (Korntved, 5% clay), a sandy loam (Ballum, 8% clay) and a silty loam (Højer, 19% clay). The crop rotation at Korntved was spring barley and winter rye while at Ballum and Højer it was spring barley and winter wheat. Both crops were grown every year. All fields had been mouldboard ploughed for decades prior to the trial period. The ploughed treatment (PL) was imposed in the autumn and the seedbed... |
