Overstory #1 - Sheet Mulch: Greater Plant Health for Less Work
Welcome to The Overstory, a free on-line newsletter for people working with sustainable forestry, agroforestry, and farming in the tropics and subtropics. Every two weeks, we'll send you a short piece to share practical information, species highlights, tips, ideas and insights, recommended books, and useful organizations. We hope you will find it helpful to you as you work to create healthy, productive plantings on your land and in your community.
Sheet Mulch: Greater Plant and Soil Health for Less Work
Summary: Sheet mulch can substantially increase plant growth and health by encouraging soil health, helping to retain soil moisture, and suppressing weed growth.
If you are asking yourself how to improve the growth and health of your plantings, our answer is: sheet mulch. We have seen mulched plants and trees grow more than double the rate of their unmulched counterparts in the same area. This applies not only to gardens, but to trees in orchards and reforestation projects.
Mulching in the tropics promotes plant health and vigor. Mulching improves nutrient and water retention in the soil, encourages favorable soil microbial activity and worms, and suppresses weed growth. When properly implemented, mulching can significantly improve the well-being of plants and reduce maintenance as compared to bare soil culture. Mulched plants have better vigor and consequently have improved resistance to pests and diseases. Most tropical trees have surface roots that are allowed to develop under the mulch layer, increasing plant growth dramatically.
"Sheet mulch" is a layer of decaying organic matter on the ground. Mulch occurs naturally in all forests; it is a nutrient rich, moisture absorbent bed of decaying leaves, twigs and branches, teeming with fungal, microbial and insect life. Natural mulch serves as a "nutrient bank," storing the nutrients contained in organic matter and slowly making these nutrients available to plants.
Mulch forms a necessary link in nutrient cycling vital for soil, particularly in the tropics. When mulch is absent for whatever reason, the living soil is robbed of its natural nutrient stores, becomes leached and often desiccates. Natural environments without a litter layer are usually deserts. Non-desert plants grown in bare soil require constant fertilization, nutrient amendment, and water, not to mention the work required to keep the soil bare.
Sheet mulching is a highly effective layered mulching technique for controlling weeds and improving soil and plant health with mulch. The process mimics the litter layer of a forest floor.
The benefits of mulching justify putting the energy into doing the job right, using ample materials. A significant reduction in maintenance and increase in plant vigor will reward the initial effort many times over. Eventually, other tasks such as watering, fertilization and weed control will be reduced. The overall maintenance burden in mulched conditions, when properly executed, is far less than in conventional systems.
To learn more about sheet mulching, including a step-by-step outline of how to do it for tree plantings and gardens, see our full article, Sheet Mulching: Greater Plant and Soil Health for Less Work.
Other references include:
- Molly Curry's article, "Sheet Mulch Now!" in The Permaculture Activist, issue No. 34-A, August 1996. Order from The Permaculture Activist, P.O. Box 1209, Black Mountain, NC, 28711, USA; e-mail: firstname.lastname@example.org
- Bill Mollison's excellent Permaculture: A Practical Guide for a Sustainable Future, published by Ten Speed Press and available from bookstores.
- Ruth Stout has written many books covering sheet mulching, including the recently reprinted Gardening Without Work: for the Aging, the Busy and the Indolent.
About the Authors
Kim M. Wilkinson is the Education Director for Permanent Agriculture Resources and editor of The Overstory. She has B.A. degrees in Anthropology and Ecology from Emory University.
Craig R. Elevitch is an agroforestry specialist with more than ten years of public and private sector experience in tropical agroforest and forest management. He has a M.S. degree in Electrical Engineering (Dynamical Systems) from Cornell University.
Related Editions to The Overstory
- The Overstory #70--Rhizosphere
- The Overstory #66--Carbon Sequestration: Storing Carbon in Soils and Vegetation
- The Overstory #29--Tropical Green Manures/Cover Crops
- The Overstory #28--Microlife
- The Overstory #22--Pioneering Difficult Sites
- The Overstory #20--Five Fertility Principles