Effect of tillage system and fertilization on physical properties of soil in the seedbed and on seedling emergence of winter barley (Hordeum vulgare cv. Niki).

In no-tillage (NT) plots, seedling emergence of barley (Hordeum vulgare cv. Niki) was better than in rotary 'hoed (minimum tillage; MT) and ploughed (conventional tillage; CT) system treatments. Soil fertilization with farmyard manure (30 tha -1 ) improved seedling emergence of barley planted on a second sowing date by up to 27, 21 and 21% in CT, MT and NT, respectively, in comparison with plots without manure. Penetration resistance (PR) in the seedbed (0-10cm) seemed to be the most relevant soil property for seedling emergence for both sowing dates. However, when we compared seedling emergence, averaged over sowing dates and fertilization treatments, with the interaction among dry bulk density (DBD), PR and mean weight diameter of aggregates (MWD), the highest correlations were found for MWD in CT (r = 0.76: P < 0.001) and MT (r = 0.56; P < 0.01). Only in the NT system did all three physical properties of soil play a significant role in the seedling emergence processes of barley, of which PR was the most important parameter (r = 0.78; P < 0.001). When manure was applied to this soil, creation of aggregates 10-20 mm and < 2 mm was favoured. Of the five aggregate sizes. only the classes 20-40 mm (r = 0.71; P <0.01) and < 2mm (r = -0.83; P < 0.001) correlated significantly with the MWD values.