Effects of tillage and fertilization on some selected physical properties of soil (0-30 cm depth) and on the root growth dynamic of winter barley (Hordeum vulgate cv. Niki)
The root mass of winter barley (Hordeum vulgare cv. Niki) at growth stages 5, 9 and 16 of the Feekes scale increased from 100% (0.272 mg cm-3 soil) to 132% and 139%, respectively. Root mass was always greater in no-tillage (NT) plots than in ploughed-tillage (CT) plots and was also greater where manure was applied in comparison to plots without manure. The root density at growth stages 5, 9 and 16 over all treatments was 0.197, 0.224 and 0.238 cm cm -3 soil, respectively. At growth stage 5, the root density in NT plots was 9% greater than that in CT plots, and in rotary hoed (MT) plots it was 3% greater. At this same growth stage, soil fertilization with NP, farmyard manure (30 t ha-1) and NP plus farmyard manure improved the root density of barley by up to 5, 10 and 11%, respectively, in comparison with control plots. The diameter of barley roots was clearly biggest in CT plots, while in NT plots the thinnest roots were found. The mean diameter was 0.63, 0.75 and 0.78 mm at growth stages 5, 9 and 16, respectively (over all treatments). Significant correlation coefficients were found between root density (RD) and the soil properties bulk density (BD), porosity (P), penetration resistance (PR) and mean weight diameter of aggregates (MWD). For example, the highest r values were as follows: At growth stage 5, r=0.95 (P < 0.001) for P and r=0.86 (P < 0.001) for MWD; at growth stage 9, r=-0.97 (P < 0.001) for PR and r=0.96 (P < 0.001) for P, and finally at growth stage 16, r=0.97 (P < 0.001) for P and r=-0.97 (P < 0.001) for PR
