1. The basic process of hydro seeder technology
Cleaning Up the Slope——Line of Survey——Mixing the Material——Hydroseeding—— Maintenance and Management.

A. Cleaning up the Slope
This step consists mainly of the clearance of the rubble on the rock surface and the loose layer, etc, to ensure the convex-concave of the slope before the construction. At the same time, it is necessary to roughen the smooth rock-face with the method of mining transverse groove, in case of the slide after spraying mixture.

B. Line of Survey
Use the level and the tape measure to determine the scope of construction and the operating area.

C. Hydroseeding
C.1 Materials of the hydroseeding
The material of hydroseeding is a mixture of the grass seed, the grass fiber, the peat, the water retention agent, the adhesive, the fertilizer, the local soil and water. Make a rational decision on the grass seed according to the local climate conditions and the grass fiber can be collected by crushing the straw and the platycodon grandiflorum. The water retention agent commonly adopts synthetic polymers, such as the polymer of acrylic acid and acrylic amide. The adhesive can be the cellulose or the glue, and the fertilizer is usually NPK. The mixed proportion of the mixture should refer to the design specification or determine by field tests.
i. Ordinary clay occupies from 40% to 50% of the mixture. It is best to choose the clay with high bonding strength, strong stickiness and greater sediment concentration, as well as high permeability after blending with other improved material. Use the local fertile soil and mellow soil whenever possible.
ii. Organic nutritional soil, which occupies from 25% to 35% of the mixture, is mainly organics such as the peat with organic matter and the fertile soil that have absorbed more long-lasting nutritional ingredient. The content of organic matter of the peat is more than 80%. The content of N.P.K is no less than 5% and the PH is from 4.5 to 6.0.
iii. The modified materials of soil, which occupies from 15%-25% of the mixture, are mainly some auxiliary materials like wood, plant fiber, poultry manure and puffed matters, etc. The purpose is to increase the water-holding capacity and the permeability of the soil and to increase buffering power, microbial activity and supply of nutrients of the soil, in order to make it easy for the roots of plants to grow, multiply and penetrate.
iv. Multi-content compound fertilizer, which occupies from 0.6%-0.8% of the mixture, is mainly the ordinary compound fertilizer and the long-lasting compound fertilizer that has long supply period and is no easy leaking. The fertilizer effect can generally be for 2~3years.
v. The water retention agent, which accounts for 0.25% of the mixture, is an effective material for soil moisture. The moisture that absorbed and released by its expanded particles splits and enables the soil to keep water, which is available for plants to absorb repeatedly during growth.
General ingredients of 8 m3 of the soil-spraying machine: First add 3m3 of water basically to the position of the mixing axis, and then add 5 m3 of local soil and wood fiber about 12 packages. Finally add the water retention agent and the adhesive according to the proportion of 3:1.

C.2 The Construction of Hydro mulcher
The thickness of spraying material: If the slope ratio is greater than 1:0.75, the substrate thickness should be 6 cm; if the slope ratio is greater than 1:0.5, the substrate thickness should be 8 cm. Spray the mixture onto the slope, which needs to be protected, with spraying machine and ensure the spray boundary with even thickness after having stirred thoroughly the substrate and vegetation seed that have been matched. Prepared the detection scale in advance, constructors should often manage the thickness of spray-up effectively.
The thickness of spraying calculates on 8cm temporarily.
Spraying operations can be carried out according to local raw materials.
The soli-spraying can carry out several times based on the local situation. Water can be first added to the center position of the mixing axis, and put the material into the hydroseeding machine which should be stirred evenly until it reaches a proper viscosity and add the adhesive and the water retention agent, then spray the mixture onto the slope surface evenly from top to bottom. After reaching the required thickness, finally put material and grass seeds into the hydro seeder machine, and then add water to stir evenly. After the mixture ready, spray and reach the thickness of the final design. The thickness of the spray layer can be increased in such fractured lithology and hard-rock slope areas.

D. The Selection and Matching of Plant Species of the Material
The key of the quality of slope greening is the selection of plant species. Grass seeds and tree species should be selected with that seeds with roots flourishing, short stem and leafy, as well as high survival rate and being appropriate to local conditions. Spraying content of seeds is not less than 15~20g per square meter.

E. The Management of Covering and Conservation
After spraying seeds, cover the slope with non-textile to avoid the rain-wash and fasten with U-wire nail.

F. The Conservation Management at Seedling Stage
Maintain after covering and remove the coverings until all of the seed germination, and then fertilize and provide the pest control in different stages.
Water at least once a day at seedling stage and also can adjust times of irrigation based on the intraday weather conditions. Spraying water in a frosted appearance to ensure the new-soil is fully wet. Far better to water in the morning or evening, it is prohibited to water at midday. The regular fertilization should be based on the growth state of plants. At seedling stage, there should be professionals to observe regularly every day, and to find insect damage and to control in time. One month after the spraying, it is essential to carry out a comprehensive examination of the grass growth and to reseed at the place of uneven growth obviously.