EFFECTS OF SEWAGE SLUDGE APPLICATIONS TO AGRICULTURAL SOIL ON THE BIOCHEMICAL PARAMETERS OF FABA BEAN (FABA SATIVA BERNH.), WHEAT (TRITICUM AESTIVUM L.), SPINACH (SPINACIA OLERACEA L.) AND CUCUMBER (CUCUMIS SATIVUS L.) CROPS

Abstract

This study aimed to assess the sewage sludge (SS) amendments to agricultural soil on the biochemical composition of four plants (faba bean, wheat, spinach and cucumber). The applied SS rates were 0, 10, 20, 30, 40 and 50 g/kg soil. Plant leaves 45 days after SS treatments were used in biochemical parameter analyses. Starch decreased in spinach from 179.34 to 41.38 mg/g DW with SS treatments and increased in faba bean, wheat and cucumber at 10, 20, 30 and 40 g/kg rates. Water soluble carbohydrates and total non-structural carbohydrates declined in the four plants with SS treatments. Total lipids increased in faba bean and spinach up to 41.94 and 7.89 mg/g FW, respectively, at the SS amendment of 50 g/kg, while in wheat and cucumber the increase was detected only at 40 and 50 g/kg rates. In spinach, the accumulation of proline started at SS treatment of 10 g/kg, while, for wheat and cucumber the increase of proline was started at 20 g/kg SS. The highest proline accumulation was 0.96 mg/g FW in spinach at 50 g/kg SS rate. SS did not affect phenol content in faba bean and spinach with any treatment, whereas, the phenol declined in wheat and cucumber.