TECHNOLOGY FOCUS - AGRICULTURE - Preferred Method: The method further involves paving the shaped lawn soleplate at the place where a lawn would be built, and watering for days to emerge and grow into lawn. The method preferably involves (i) using sludge, Cyanobacteria and water hyacinth as main raw material, wheat straw or rice straw and chicken manure and/or pig manure as additives, firstly performing composting fermentation, where the water content of the sludge is 75.2%, the dry radical content of the organic matter is 38.1% and the volume weight is 1.19 g/cm, the compost place can be lee, sunny place and water approaching place, where the proportions of the materials comprises (in weight) sludge (10000), Cyanobacteria and water hyacinth (500), wheat straw or rice straw (50), water (100) and Manchunyuan biological fermenting agent (3), during compost, crushing the water hyacinth to the extent that the longest piece is not greater than 2 cm, cutting the wheat straw into crushed material about 5 cm long, then adequately mixing the above material in a mixer, spreading on the ground, sprinkling a layer of biological fermenting agent, blending in excrement and water, blending and composting and stirring the mixture uniformly to compost into stock pile of 1-1.5 m high, where the composting performs when the outdoor temperature reaches more than 15 degrees C, the temperature of the stock pile is gradually increased after 5 days and the highest temperature reaches 70 degrees C, the stock pile is turned over once a day, the temperature is reduced and the air permeability of the material is kept, when the temperature of the material does not increase or decrease any longer, the change is steady, the outer appearance is pitchy and contains white coenobium and obtaining base material, (ii) filling the die with lawn base material and putting the reinforced ribs, where the reinforced rib rice straw or wheat straw which is cut into a length slightly less than the inner diameter side length of the die, (iii) uniformly spray seeding grass seeds on the upward surface of the lawn base material, where the grass seeds are chosen from seeds of American grasses, Canadian grasses, Australian grasses, Argentine grasses, New Zealand grasses, Danish grasses, Taiwan grasses, Korean grasses, Hawaiian grasses, annual meadow grass, Festuca arundinacea, rye grass, wire grass, bent grass, white flower clover, red flower clover, weeping love grass, white grass, Zoysia matrella, Bermuda grass, Desmodium, Puccinellia distans, Japanese zoysia and ophiopogon root, the amount of the grass seeds is 8-20 g/square meter, preferably 10 g/square meter (iv) covering the grass seeds with soil and press forming, the die is square frame structure made of wood or steel, the side length is 30-50 cm and the thickness is 3-8 cm, preferably 5 cm, (v) press forming to form precast slab of lawn, (vi) paving the shaped lawn soleplate at the place where a lawn would be built and watering for days to emerge and grow into lawn.