Abstract

                                Field experiments with 16N-labelled and non-labelled N showed that the dual advantage of deep placement and slow-release of fertilizer N could be achieved through the use of mud balls. In terms of yield. N uptake and recovery, the mud balls compared favour- ably with shellac or sulphur-coated urea. They were also found effective in reducing the loss of fertilizer N through leaching. However, the behaviour of mud balls appeared to vary depending upon the N rate. source and decomposibility of associated carbonaceous material Alternate cheap methods for mud ball application in flooded rice culture are suggested.

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