(188b) Evaluation of Binderless Board Made from Composted Rice Straw As Substrate for Rice Seedling Production

China is the largest rice producer and consumer in the world; approximately 20% of arable China’s lands is annually devoted to planting this valuable crop. With the increase of China’s population, the rice yield will increase to 7850kg/ha by 2030, resulting in a total of 200 million kg of rice per year to feed the Chinese people. Therefore, China has the potential to produce a large amount of rice straw. Today, compost plays the major role as a peat substitute. Composts straw have beneficial attributes, such as providing plant nutrients, suppressing disease, promoting the growth of beneficial microbes. In this paper, the straw was composted under controlled condition to form the rice seedling substrate. After the composted straw was beated for an hour, the substrate block with dimension of 27 cm ×55 cm × 1 cm were formed by vacuum adsorption from water.

The nutrient in the substrate block, including organic matter, nitrogen, phosphorus and potassium, was improved significantly in comparation with the traditional substrate. The results of rice seedling grown in straw-based substrate block showed that the seedling height, stem diameter, root length, leaf area, SPAD of rice produced from the substrate block are nearly the same as the normal substrate. And after transplanted, the effective tillering number improved 7.4%, the yield of the rice improved 5.7%, the ratio of straw to grain decreased 11.5%. That is to say, the straw based substrate can reduce ineffective tillering, and decrease the amount of produced straw.

The substrate block can substitute the seedling tray and reduce the agricultural white pollution. Agricultural wastes in rice production can be utilized and recycled. In addition, the labor intensity and cost of rice seedling production can be reduced, and the rice production efficiency was improved.