Manganese (Mn) and Lead (Pb) Content in Lemna Culture Fertilized by Bioslurry

Lemna minor is a small water plant that floats on water and has the potential to be fresh feed for fish. Bioslurry is a by-product of the management of biogas from livestock manure which is often used as fertilizer for plants because it contains nutrients in a readily available form. Among the contents contained in bioslurry, manganese and lead are important things related to their use for plants and fish. This study aims to determine the mineral (Mn) and lead (Pb) content in the medium of lemna cultivation which is fertilized with various doses of bioslurry. The study was conducted at the Ciparanje Experimental Pond, Faculty of Fisheries and Marine Sciences, Universitas Padjadjaran, Indonesia. This study used an experimental method with Completely Randomized Design (CRD) with four treatments with three replications. The treatment in the form of adding bioslurry to the lemna culture media was 0.00%, 0.25%, 1.00% and 2.50% of the volume of water. The minor density of Lemna used is 800 g/m2. The culture was carried out in 4 cycles for 7 days. The parameters observed were Mn and Pb content in the lemna culture medium shortly after the addition of Bioslurry and after 7 days of lemna cultivation. Based on the results of the study, the use of 2.5% bioslurry concentration can produce the highest Mn content with a range of 2.0-4.6 ppm and 2.92 ppm Pb content after 7 days of lemna cultivation. In addition, the use of 2.5% bioslurry concentration resulted in Mn and Pb values in the culture medium shortly after stirring bioslurry in the lemna culture media. Based on the research results, the treatment of adding 2.5% bioslurry to the lemna culture media is the best dose for produced Mn for fish, as well as the safest Pb for aquaculture activities.