Mudball application of fertilizer
By Rizal A Gatica
Putting fertilizer in mudballs and then deep-placing these mudballs at the center of every four rice hills may seem a strange way of applying fertilizer. But experiments at the International Rice Research Institute (IRRI) show that the mudball technique (as it is called) is superior to other methods of application including broadcast, topdressing, and foliar spraying.
Says Surajit K. De Datta, 40, head of the IRRI’s agronomy department which is conducting the experiments: “Applying fertilizer using the mudball technique results in significantly higher yields at lower fertilizer rates. You have to use 100 kilograms of fertilizer per hectare if you use the broadcast method during the dry season; using the mudball method, you apply only 60 kilograms – and save 40 percent fertilizer with no reduction in grain yield. And you save more fertilizer during the rainy season, when you need only 30 kilograms of fertilizer per hectare instead of 60 kilograms of nitrogen needed when other methods are used. In addition, you fertilize only once if you use the mudball method, whereas you fertilize two or three times if you use the broadcast method.”
IRRI experiments on mudballs began as early as 1966, but intensified in 1973 when the supply of fertilizer dwindled.