Chris Meuli is a physician, the grandson of a conservation rancher, and a lifelong resident of New Mexico. His inherited interest in in the land led him to permaculture literature in 1981. Mr. Meuli is a graduate of the 1992 design course in Eldorado, New Mexico. Mr. Chris Meuli came up with the brilliant idea of soil sponging. As stated in my earlier post, soil sponges are holes dug in the ground that are filled with organic material (such as paper, cardboard, wood chips, etc.). The purpose of the soil sponges are to absorb and slow down the flow of water on a downward slope. The water is then redistributed among the area, allowing nearby trees and plants to thrive. Below is a picture of a soil sponge my friend Will and I created in the Desert Oasis Garden.
Soil Sponges with Will and Christian
Mr. Chris created a useful reading that is titled, Sponge Ladders: A Water Harvesting Method for Establishing Perimeter Shelterbelts on Sloped Sites. In this reading, he explains exactly how simple it is to create a water sustainable garden. He explains that no matter the size of the landscape we are using, results will be effective. Mr. Meuli states the importance of nearby shrubs and trees among the shelterbelt landscape. Shelterbelts are areas of land in which we have modified to effectively hold water. Trees and shrubs are important to have nearby, because the soil sponges/ladders will need areas to replenish with water. The true difficulty is, many of the sights we want to modify are not level. It is very challenging to hold rapid water runoff from the rainfall long enough to soak into the soil sponges.
A possible solution to this problem that Mr. Meuli suggests, is the use of a Fishscale swale. A Fishscale swale is the act of creating mounds and holes around the landscape to stop the flow of water. For more details, click on this link http://barbaramatthews.wordpress.com/. Although Fishscale swales are effective, Mr. Meuli states that they have to carefully monitored. If the swales become silt in, they allow water to overflow away from the shelter belt. Below is a picture of a Fishscale swale:
Mr. Meuli has been dealing with this problem for many years on his steep-sloped landscape out in Edgewood, New Mexico. With much experimentation, Chris was able to create the solution of sponge ladders. The process of creating sponge ladders is quite simple. Sponge ladders consist of very short and deep swales, that collects and holds water along a shallowly dug runway that runs off contour. The waterway if very important, for it guides the water parallel to the property, allowing it to soak into the shelterbelt soil. In order for maximum effectiveness, soil sponges must be placed at 6 to 15 foot intervals along the waterway. If properly placed, the soil sponges slow down and absorb the water, which helps the soil and nearby living plants. Due to the organic material in the soil sponges, the water is easily stored in the hole. Below is a picture of organic materials going into a soil sponge in the Desert Oasis Garden:
Adding old newspaper to the holes
He states that it is important to remember that the top of the fully covered soil sponge is even with the bottom of the waterway. If positioned correctly, it allows surplus water to run down the water way to the next sponge. This effectively maximizes the amount of absorption of water along the edge of the property. It also facilitates the establishment of the perimeter of the shelterbelt. The soil sponges are dug with shovels and are approximately 2 feet wide and 6 feet long. Their depth can range, but the average depth is 15 inches deep.
Soil sponges are very effective if the organic material is replaced with new material every three to five years. This allows them to renew their absorptive capacity. The old material being replaced can be placed in the shelterbelt soil as a rich dressing. Useful trees that can be planted at the shelterbelt site include the following: Austrian Pines, Scotch Pines, Rocky Mountain Junipers, Eastern Red Cedars, Apache Plumes, New Mexico Privets and Black Locusts (possible invader species). Overtime, results should be seen within your shelterbelt site. Not only are soil sponges a very useful water flow for your plants and trees, they also attract a variety of wild life. You can have a site that contains healthy happy trees, and house many different species of birds and little critters!
Photographs were taken by Mrs. Beamish
Anika Gorham
Student Investigations in Agro-Ecology 