Composting the Wastes from a Rice Processing Plant

Cooperating agency for this topic:
Malaysian Agricultural Research & Development Institute (MARDI), 2001-12-01

In Malaysia, the "Titi Gantung" Paddy Seed Processing Plant processes 2,300 mt of rice seed every year. Besides producing rice seed, it also produces waste by-products such as rice straw, leaves and stems, rice husk, dust and other wastes, estimated to come to 120 - 140 mt each year.

Disposal of these wastes is a problem. Proper waste disposal costs about US$ 2,183 per year. Burning them in open fires is not environmentally friendly, while leaving them to rot down by themselves takes too much space.

To resolve this problem, it was decided to recycle the waste products to produce compost. The compost can be used as an organic fertilizer, and as a soil conditioner on farms.

Composting the Waste Products

The wastes are soaked in water for overnight or for 36 hours, together with other materials including urea, GML lime, chicken manure, organic clay and muck soil. The excess water is then drained out, and the wastes are piled onto to a piece of plastic and covered with a plastic sheet, to maintain the moisture content during composting.

The compost pile is watered and turned once every 30 days, for 180 days. Turning the heap ensures that the materials are well mixed. This allows even decomposition until the wastes have become a mature compost ( see Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10).

Analysis of the Compost

Analysis shows that the compost produced is of high quality, and is equal to compost made out of any other organic matter. Its nutrient content is shown below (Table 1).

Cost of Production

The cost of production of the compost is US$ 35.51/mt, including the basic materials, facilities and manpower. In terms of yield, for every 1 mt of waste, 1.35 mt of compost is produced. The greater amount of compost is because of its higher moisture content.

Production, Distribution and Sale

In 1998, a total of 57.7 mt of compost was produced in Malaysia from the wastes from the processing plant. Of these, 51.95 mt with a value of US$ 6,831 were distributed to Agriculture Offices and sold to farmers and the public.

Index of Images

Figure 1 Concrete Tank in Which Wastes Are Soaked.
Figure 2 Pouring Rice Husk into the Concrete Tank.
Figure 3 Watering the Husk.
Figure 4 Adding Other Materials to the Tank.
Figure 5 Heaping of the Materials.
Figure 6 Covering the Compost with a Plastic or Canvas Sheet.
Figure 7 Turning the Compost to Aid Decomposition.
Figure 8 Watering the Compost
Figure 9 Mature Compost, Ready to Use
Figure 10 Use of Compost from Rice Waste As Growing Medium for Cabbage and Chili
Table 1 Nutrient Content of Compost