NOVELTY - Production of lake sludge carbonized nutrient soil involves mixing and extruding lake sludge nutrient soil raw material into sheet-shaped particles, carbonizing in a rotary carbonization furnace, spraying water in the furnace using high-pressure water spray nozzle, granulating carbonized semi-finished nutrient soil to particle diameter of 6-12 mm and particle length of 6-20 mm, sterilizing obtained soil particles at low temperature, drying at 60-100 degrees C for 30-90 minutes, cooling obtained soil having moisture content of 20% or less, and packaging.    USE - Production of lake sludge carbonized nutrient soil used for planting flowers and plants, and nursery-grown plants.    ADVANTAGE - The method enables production of odor-free lake sludge carbonized nutrient soil with high quality and fertilizer efficiency, and excellent water retention capacity.    DETAILED DESCRIPTION - Production of lake sludge carbonized nutrient soil involves mixing and extruding lake sludge nutrient soil raw material into sheet-shaped particles having thickness of 8 mm or less, carbonizing sheet-shaped particles at 250-450 degrees C for 30-90 minutes in a rotary carbonization furnace, spraying water in the furnace using high-pressure water spray nozzle, obtaining carbonized semi-finished nutrient soil with moisture content of 25% or less, granulating carbonized semi-finished nutrient soil to particle diameter of 6-12 mm and particle length of 6-20 mm, sterilizing obtained soil particles at low temperature, drying at 60-100 degrees C for 30-90 minutes, cooling obtained soil having moisture content of 20% or less, and packaging. The lake sludge nutrient soil raw material comprises 15-35 wt.% lake sludge, 10-30 wt.% waste activated clay, 5-25 wt.% peat, 0-20 wt.% attapulgite clay, 0-15 wt.% bentonite, 2-15 wt.% zeolite, 5-15 wt.% crushed waste, 0.5-5 wt.% vermiculite and 5-35 wt.% water. The lake sludge carbonized semi-finished nutrient soil comprises 45-75 wt.% carbonized lake sludge soil, 5-25 wt.% water retting system waste, 0.2-10 wt.% diammonium phosphate, 0.5-5 wt.% expanded perlite, 0-5 wt.% ferrous sulfate, 0-5 wt.% superabsorbent and 5-35 wt.% water. The water retting system waste comprises 35-75 wt.% crushed waste and 25-65 wt.% water, and is prepared by immersing crushed water in water, and performing water retting process for 10-30 days.