USE OF AQUACULTURE EFFLUENT AS A SUPPLEMENTAL SOURCE OF NITROGEN-FERTILIZER TO WHEAT CROP

A field experiment was carried out on sandy-clay-loam soil on the use of aquaculture effluent as a supplemental source of nitrogen fertilize r to wheat crop in 1991-92. The mean ranges for different crop growth parameters under various fertilizer treatments were plant height betwe en 51.9 and 74.8 cm (well water) and between 60.7 and 79.0 cm (aquacul ture effluent); greenmatter yield between 6.9 and 22.8 Mg ha-1 (well w ater) and between 9.6 and 25.1 Mg ha-1 (aquaculture effluent); drymatt er yield between 1.71 to 4.53 Mg ha-1 (well water) and between 2.28 to 4.89 Mg ha-1 (aquaculture effluent); total biomass between 5.5 and 18 .7 Mg ha-1 (well water) and 7.1 and 18.8 Mg ha-1 (aquaculture effluent ); grain yield 1.68 to 7.70 Mg ha-1 (well water) and 2.70 to 7.97 Mg h a-1 (aquaculture effluent); straw yield between 3.8 and 11.0 Mg ha-1 ( well water) and between 4.4 and 10.9 Mg ha-1 (aquaculture effluent); a nd the number of tillers per plant from 2.06 to 4.63 (well water) and from 3.19 to 5.81 (aquaculture effluent). Overall, the results obtaine d with 25 to 50% nitrogen application under aquaculture effluent irrig ation were comparable with those obtained with 75 and 100% nitrogen ap plication under well water irrigation. In conclusion, a 50% saving in nitrogen application as an inorganic fertilizer can easily be achieved if crops are irrigated with aquaculture effluent containing around 40 mg N L-1.