HYDROPONIC GROWING OF LETTUCE (Lactuca sativa L.) USING ORGANIC LIQUID FERTILIZER PRODUCED FROM COW MANURE AND ONION PEELS

Abstract

Recently, the use of organic liquid fertilizer assumed as a proper and practical fertilizer for plant productivity purposes. This study aimed to produce ecologically friendly organic liquid fertilizer from cow manure and onion peels that can be used for hydroponic growth of lettuce (Lactuca sativa L.). The fermentation process was carried out in open container covered with cotton cloth (to prevent entries of insects). After 43 days of fermentation the mixture was converted in to organic liquid fertilizer with which its degree of readiness was shown by organoleptic properties (homogeneity, looseness, lack of smell). Compost tea refers to fermenting well-characterized compost in water for one day and filtration prior to application. The experimental design used was complete randomized design (CRD) in two replications. The composition of macronutrient, pH and Electrical conductivity were analyzed quantitatively and the results showed that organic liquid fertilizer contained 2.61%, 1.82 %, 2.84%, 2.69%, 4.94%, 3.38% and 36.73 of Nitrogen (N), Phosphorous (P), Potassium (K), Calcium (Ca), Magnesium (Mg), sodium (Na), carbon (C), respectively. Furthermore, the C: N ratio, pH and EC of the liquid organic fertilizer were 14.26, 6.52 and 0.76 dS/m, respectively. In contrast, compost tea contained 3.57%, 0.85%, 2.29%, 1.93%, 3.67%, 1.29% and 22.49% of N, P, K, Ca, Mg, Na and C while its, C:N, pH and EC were 6.37,6.35 and 0.67dS/m, respectively. Hydroponic grown lettuce treated with organic liquid fertilizer produced from cow manure and onion peels showed that 122.77 g/plant, 12, 86 and 62 of above ground biomass per plant (ABMW), number of leaves per plant (NLP), head weight per plant (HWP) and days to maturity (DM), respectively. However, hydroponic grown lettuce treated with compost tea showed that 96.95, 7.5, 36.9, and 92 ABMW, NLP, HWP and DM, respectively. Lettuce grown in pot contained soil as medium treated with organic liquid fertilizer showed 77.71,9, 56.25, and 82.50 ABMW, NLP, HWP and DM respectively. However, lettuce grown in pot contained soil as medium treated with compost tea showed 66.92, 5, 30.5, 99.5 ABMW, NLP, HWP and DM, respectively. Organic liquid fertilizer has many advantages because it is relatively easier to process, can be produced from local available substrates, high plant nutrient and has no side effects. Lettuce grown under hydroponic system showed higher performance than soil based grown treated with organic liquid fertilizer. It is recommended that farmers can cultivate lettuce in hydroponic system using liquid organic fertilizer since quality lettuce was cultivated in the present study