Fertilizer from fish waste

Tuna processing units in Lakshadweep generate huge quantities of processing waste, which is conventionally thrown into the lagoon, where it causes occasional eutrophication. In an attempt to utilize this nitrogen rich processing waste in agriculture instead of polluting the water body, a fish fertilizer was produced using the composting bacterial consortia developed by Kerala Agricultural University. Waste from the Masmin production industry comprised mainly of the head of the fish, its vertebral column and offal. The head being a bigger mass was longitudinally split before adding to the composting pit. The bacterial consortium was established on to coco-peat from the pure culture. First a foundation layer of this coco-peat mixture was laid in the pit above which the split heads of tuna were arranged in layers with intermittent layers of coco-peat. The mixed offal was dripped in between the heads and a total of 5 layers were laid. It was finally covered with another layer of coco-peat and then with dry sawdust to prevent flies from laying eggs and to facilitate the breathing of compost. The pit was covered using a tarpaulin to prevent direct sunlight and rain. The setting was left undisturbed for 56 days, during which the hard mass was converted into a powdery mixture with some bones left undigested. A ground mixture of the same was analyzed and the composition was found to be Nitrogen – 10.23%, Phosphorus – 3.96 %, Potassium – 0.61%, Calcium – 6.78%, Magnesium – 0.35%, Sodium – 1.65%, Carbon – 38.12. The produce was successful in producing healthy foliage in Chilly and Brinjal.

Benefit:The product is a solution to the poor fertility of the calcareous soil in Lakshadweep and an alternative to the age-old practice of discarding tuna processing waste at sea.

Source : Contact person with Name, Designation e-mail and phone no: A.K.O. Ratheesh, Scientist, E-mail : arun.ratheesh@icar.gov.in Mob: +91 9474238621