Effect of growing media on mat type seedling raised for mechanical rice transplanting

Mechanical transplanted seedling must meet the requirements of standard seedling block with uniform distribution of seedlings and inter-twisting roots for rolling. This study was conducted to identify the effect of growing media on mat type seedling raised for mechanical transplanting at Bangladesh Rice Research Institute (BRRI), Gazipur during the period of 2012-2014 covering two dry and cold seasons (Boro) and one wet season (Aman). Seedling were raised on plastic tray using sandy loam and clay loam soil mixed with decomposed cow-dung, mustard cake, rice straw organic fertilizer, rice bran, poultry litter and vermicompost at the rate of 0.0, 10, 20, 30 and 40%. Rolling quality of the seedling mat decreased and seedling height increased with the increased of mixing rate of organic fertilizer except rice bran and mustard cake. Averaged across three seasons, 10 to 30% cow-dung, rice straw organic fertilizer, vermicompost, 10% poultry litter and 20 to 30% rice bran with both types of soil was found suitable for seedling mat and seedling height. However, seedling varied among the organic fertilizers with both types of soil in the order of cow-dung > rice bran > vermicompost > poultry liter > rice straw organic fertilizer > mustard cake. Clay loam soil showed better performance on rolling quality over sandy loam soil.