Abstract: In order to optimize the volume ratio of different raw material,fermentation time and pH value in the process of preparation of rice seedling nutrition substrate, which utilizing crop straw as the main raw material,several experiment were conducted. Firstly,an aerobic fermentation test experiment was conducted using different volume ratio of crop residues to beer sludge to study the optimal fermenting technical conditions. Secondly,a screening experiment was conducted with different acidity regulators to reduce the pH value of compost substrate. And then,a growth experiment was conducted to evaluate its applied effects on rice seedling growth. The results indicated that the optimal conditions of the fermentation could be volume ratio of crop residues to beer sludge of 1∶1 or 1∶2,which could reduce the fermentation time by 7 days as compared with the normal. 10 g/kg sulfur were the best individual acidity regulators,and the optimal formula of compound acidity regulator was 2% gypsum mixed with 3% superphosphate. The application effects of compost testified that of group 4 matrix formula of nutrient（70% organic material+10% turf+10% vermiculite+5% humic acid+1% gesso+4% superphosphate） was balance and good in properties of physical and chemical and retention of water and nutrient. It could meet the low temperature in early spring and dry seedling and demand for trans-planter machine in southern China.

Key words: crop straw, beer-sludge, compost, properties regulation, rice seedling nutrition substrate