**4.2.5 Fertilizer**

To enhance the growth of plants, chemical grade fertilizer, in accordance to Bureau of Soil Recommendation, is added in to ameliorate common soil nutrient deficiencies. It is an organic fertilizer locally produced in palletized form that is both environmental friendly and non-toxic.

## **4.3 The soil for the test box**

To maintain good vegetation, the soil must meet certain requirements as a growth medium. It should meet the following conditions:


The soil used was sieved to separate large stone and other unnecessary things not needed.

For every layer of 10 inch, the soil in the test box is compacted with use of ply board, a piece of wide flange or bricks. Compaction is done by placing the ply board on top of each layer to

Combined Hydroseeding and Coconet Reinforcement for Soil Erosion Control 219

With the hydroseeding completed, the coconet is installed over the entire hydroseeded area as shown in Fig. 5. To ensure total coverage of the slope, nets are laid adjacent to each other and were anchored securely on the slope with bamboo pins or any other appropriate

Fig. 5. Hydroseeded test boxes covered with coconet. The green net is used for protection

In this study, a laboratory test was performed using the Artificial Rainfall Simulation Apparatus at the Hydraulic Laboratory of the Flood Control and Sabo Engineering Center (FCSEC) of DPWH to assess the effectiveness of Hydroseeding with Coconet in erosion control and water run-off. The rainfall simulator is capable of creating uniform drops and desired intensities. This is used to apply uniform rain over the entire area of the specimen. In this study the researchers will use the worst rainfall rate which is 120 mm/hr. The rainfall

The FCSEC artificial rainfall simulator is a device with adjustable /changeable nozzle for rainfall intensity variation. The said simulator has a dimension of 10m x 5m x 10m that produces drops simulating rainfall intensity of up to 235mm/hr. Raindrop sizes are representative of typical heavy rains/storms in the country. The spatial distribution of rain is essentially uniform, and the control of application rates is within the accuracy

For the rainfall simulation on the study's test specimen, the rainfall applied was at 120mm/hour for every 10 minutes. The sediment and water runoff from the test box were

**4.6 Installation of coconet** 

from birds and other factors.

simulator used is shown in Fig. 6.

requirement of most experimental protocols.

**4.7 Rainfall simulation** 

collected.

material(s) depending on the nature of the slopes.

flatten the soil and will be compacted by dropping the wide flange five times with the height of 8 inch. If wide flange is unsuitable for compaction for small area, bricks may be used.
