Influence of Salinity of Water for Irrigation on NPK Nutrients Uptake in Greenhouse Traditional Cultivation of Cauliflower (Brassica oleracea var. botrytis L.)

Abstract

The NPK nutrients uptake in the production of cauliflower (Brassica oleracea var. botrytis L.) irrigated with different water quality (fresh and saline water of 4 dS/m) has been analyzed in the experiment conducted in the greenhouse of Mediterranean Agronomic Institute of Bari. The highest nitrogen (N) consumption was observed 10 weeks after transplantation, while the highest consumption of phosphorus (P) and potassium (K) was recorded 12 and 8 weeks after transplantation, respectively. The highest concentration of N in vegetative part was obtained in cauliflower under saline water irrigation (3.5%), while in the fresh water treatment concentration of N was 3.2%. The phosphorus uptake was significantly affected under saline irrigation practice with respect to the fresh water being with total P uptake value corresponding to about 61% of the its uptake under the fresh water treatment. Irrigation with the salinity level of 4 dS/m resulted in significant increase in the accumulated salts in soil being with an electric conductivity (EC) value 17% greater than the one where fresh water was practiced. Evolution of chloride (Cl^-) and its average values during the whole cropping period indicate that Cl^- behaved in a manner identical to the one characterizing the EC parameter. This proves that Cl^- concentration in the soil can be taken as a measure expressing the soil salinity.