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.
“We tested various fertilization methods,” says De Datta, “to test their efficiency in terms of high yield and lower rates of application. We found that the use of mudballs would significantly aid small farmer in increasing his yield. The mudball technique is designed primarily for rice framers cultivating one hectare or less.”
How does one apply fertilizer using mudballs? De Datta gives the following steps:
A few days before transplanting, prepare the mudballs; a hectare would require about 62,500 mudballs. Each mudball should be three centimeters in diameter. Make an opening in its center with your thumb; place the fertilizer in this space, then close the mudball. Immediately after transplanting or during transplanting, insert the mudballs 10 to 12 centimeters beneath the soil surface at the center of every four rice hills. When doing this, the paddy must not contain too much standing water; the water level should be one to three centimeters only.
To illustrate the efficiency of the technique, De Datta cites the results of their 1974 dry season experiment at IRRI: “Using mudballs, wee produced eight tons of rice per hectare with 60 kilograms of nitrogen. In contrast, we produced only 6.6 tons per hectare using 100 kilograms of nitrogen applied as topdressing. Obviously, concentrating the nitrogen and placing it deep enough in the paddy reduces the loss of this important nutrient, thus enabling the plants to utilize it to the maximum. When fertilizer is broadcast, much of it is lost and plants do not readily absorb it.”
De Datta says the technique may be used in both irrigated and non-irrigated farms. However, better results may be obtained in irrigated farms.
Mudball application of fertilizer has been tested in farmer’s fields in the Philippines, Thailand and India – with encouraging results.
Says De Datta: “We are demonstrating the mudball method to farmers in Nueva Ecija to convince them that the technique is feasible in their fields – not just in IRRI’s farms. We are gratified by their interest in it.”
However, no one in the Philippines is using the technique on a large scale, mainly because it’s too labor intensive. “I don’t think many farmers will be willing to work so hard preparing thousands of mudballs just to save on fertilizer,” adds De Datta. “That’s why we don’t recommend the technique to every farmer in Asia. For small farms that are only one hectare or less in size, such as those commonly foung in Java, Indonesia, Bangladesh, and parts of India, the technique should prove very practical. That’s why we don’t encourage its use in these countries, as well as in Thailand and Sri-Lanka. Incidentally, all these countries are working with IRRI to increase the efficiency of fertilizer use.”
For the Philippines, De Datta says IRRI scientists are looking for a fast, less laborious method of applying the mudball concept. “Our engineering department has developed a machine that can place the fertilizer directly into the soil 10 to 12 centimeters deep.”
He adds that if urea briquets – now being developed experimentally by the Tennessee Valley Authority in the U.S. – become commercially available, mudballs won’t be necessary, and labor costs would be cut down considerably. Urea briquets – solid six-gram pellets – can be deep-placed directly in the soil without putting them in mudballs. De Datta says they have tested the briquets “and these give similar satisfactory results.”
Still, De Datta believes that the mudball technique should be used by small farmers “as long as they are willing to work hard and family labor is employed. If you hire labor, the savings in fertilizer would probably not be worth the labor cost.”
Source: Greenfields, 1976