Abstract
A field experiment was carried out on sandy-clay-loam soil on the use of aquaculture effluent as a supplemental source of nitrogen fertilizer to wheat crop in 1991-92. The mean ranges for different crop growth parameters under various fertilizer treatments were plant height between 51.9 and 74.8 cm (well water) and between 60.7 and 79.0 cm (aquaculture effluent); greenmatter yield between 6.9 and 22.8 Mg ha
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(well water) and between 9.6 and 25.1 Mg ha
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(aquaculture effluent); drymatter yield between 1.71 to 4.53 Mg ha
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(well water) and between 2.28 to 4.89 Mg ha
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(aquaculture effluent); total biomass between 5.5 and 18.7 Mg ha
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(well water) and 7.1 and 18.8 Mg ha
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(aquaculture effluent); grain yield 1.68 to 7.70 Mg ha
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(well water) and 2.70 to 7.97 Mg ha
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(aquaculture effluent); straw yield between 3.8 and 11.0 Mg ha
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(well water) and between 4.4 and 10.9 Mg ha
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(aquaculture effluent); and 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 obtained with 25 to 50% nitrogen application under aquaculture effluent irrigation were comparable with those obtained with 75 and 100% nitrogen application 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
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.