Tillage quality affecting physical characteristics, number of plants and carrot root yield under flat and ridge cultivation

Three-year long research in the field (conducted in 2008, 2009 and 2010), regarding the effects of different tillage on the soil physical properties and carrot root physical characteristics and yield, was performed for flat and ridge cultivation. The quality of presowing tillage was determined according to the bulk density (BD) and soil structure (structure coefficient, k). Ridge cultivation showed significantly lower BD values in the soil layer at the depth of 10-25 cm, and higher k values at the depths of 0-5 and 15-20 cm. By analyzing the soil layer at the depth of 0-20 cm, significantly lower BD values (by 5.5%) and higher k values (by 12.5%) were obtained under ridge cultivation in comparison to the flat cultivation. Also, under ridge cultivation, values of root length (L) were increased by 14.0%, the number of plants (N) by 25.2%, carrot root yield (Y) by 31.0% and crop growth rate (CGR) of the root by 21.3%, while the values determined for maximum root diameter (D max ) and xylem diameter (D x ) were considerably lower, by 10.1 and 23.0%, respectively. When compared to flat cultivation, ridge cultivation gave 3.5% higher carrot root mass values (M). Both types of cultivation resulted in high and statistically significant values of correlation coefficient between yield (Y and CGR) and carrot root length (L); carrot root mass (M); and number of plants (N). Strong negative influence of BD 15-20 on L and yield (Y and CGR), and positive influence on D max , for both type of cultivation, were determined. Strong positive influence of k 0-5 on N and CGR, and negative influence on D max and M, for flat cultivation, were determined. Carrot roots grown under ridge cultivation were morphologically more uniform and resulted in lower values of variation coefficient of carrot root dimensions and yields which further significantly influenced the estimation of market quality and overall carrot root price, in comparison to flat cultivation.