EFFECTS OF ORGANIC AND INORGANIC FERTILIZERS ON YIELD AND ANTIOXIDANT PROPERTIES OF LETTUCE GROWN IN A ROOFTOP GARDEN

Abstract

A pot experiment was conducted in the rooftop garden of Agricultural Botany Department of Sher-e-Bangla Agricultural University to study the effects of organic and inorganic fertilizers on yield and antioxidant properties of lettuce during November 2019 to May 2020. The twelve (12) treatments are T 0 = Soil 100%, T 1 = Soil 100% + Inorganic fertilizer, T = Soil 80% + Cowdung 20%, T 3 = Soil 90% + Vermicompost 10% , T = Soil 95% + Biochar 5% , T 5 = Soil 80% + Cow dung 20% + Inorganic fertilizer, T 6 4 = Soil 90% + Vermicompost 10% + Inorganic fertilizer, T 7 = Soil 95% + Biochar 5% + Inorganic fertilizer, T = Soil 70% + Cow dung 20% + Vermicompost 10% + Inorganic fertilizer, T = Soil 75% +Cow dung 20% + Biochar 5% + Inorganic fertilizer, T 10 9 = Soil 85%+ Vermicompost 10% + Biochar 5% + Inorganic fertilizer, T = Soil 65% + Cowdung 20% + Vermicompost 10% + Biochar 5% + Inorganic fertilizer were taken in this experiment. The experiment was laid out in Completely Randomized Design (CRD) with four replications. The results of this study showed the significant effect on shoot growth of lettuce to different treatments. Both organic and inorganic fertilizers significantly increased the growth of lettuce. The growth parameter such as plant height, leaf number, shoot fresh and dry weight increased with sole or combined application of cowdung, vermicompost and biochar in soil than control (T 11 ). But the addition of inorganic fertilizer with organic fertilizer exhibited negative effects on shoot growth but soil along with inorganic fertilizers (T 1 ) increased shoot growth than control (T 0 ). The highest fresh weight as yield of lettuce was recorded from the treatment of T (Soil 90% + Vermicompost 10%) while the lowest yield (82.23 g) was obtained from control (T ). The pattern of root growth was inconstant with the shoot growth to different treatment and suggested that inorganic fertilizers dominating the root growth than shoot growth. The different antioxidant compounds of lettuce leaf such as vitamin C, phenolic and flavonoid content increased with sole application of organic fertilizers and combined application of inorganic and organic fertilizers in more than control (T ). But inorganic fertilizers decreased the vitamin C, phenolic and flavonoid content. These antioxidant compounds content were constant with the DPPH activity with low IC 50 0 value. The IC values obtained from the DPPH radical scavenging assay. The IC 50 50 values of DPPH radical scavenging activity highly correlated with total phenolic content and total flavonoid content. Therefore, the results recorded that sole application of organic fertilizers improved the yield and quality of lettuce than sole application of inorganic fertilizers, and even combined application of organic and inorganic fertilizers in soil media grown under rooftop garden conditions. 8 3 0 2 0