Realistic Grass

Step 1
Growing grass
From the Get > Primitive > Polygon Mesh menu chose Grid. Press [Ctrl] + [2] to switch to the Hair Toolbar. From the Create > Hair menu chose From Selection. In the Hair PPG, set the number of Total hairs 13000 or so. The lawn is still way to sparse, but using the Strand Multiplier will be more efficient than further increasing the Total hairs, so set it to 2. Next, set the Splay at tip to 0.5 and the Splay at root to 0.25 to separate the strands.

Step 2
Adding variation
Switch to the Effects tab. Change the Root Thickness to 0.5 and the Tipp to 0.2. Set the Random Scale to 0.7. The Fizz and Kink parameters enable you to breakup the uniformity and add natural noise and variations to the strands in addition to the standard styling tools. Use the values in the screenshots as a guide rather than the ultimate settings. Please do take the time play with them, as well as the different styling tools.
Step 3
Green grass
With the hair selected, press [7] to open the Render Tree and click the Hair_Renderer node to open the PPG. As the name might imply, the default settings are more suited for hair than grass and this is not only as for the color but perhaps more importantly, the transparency. See previous screenshot for settings. If you haven’t done so already, enable the shadows for at leas on light in your scene, as this will make all the difference.

The project files used in this tutorial can be found at:
http://www.Redi-Vivus.com/Caffeineabuse/RealisticGrass.zip