Overstory #10 - Sequential Planting
Sequential Planting: Short-term returns combined with long-term plantings
Trees are the backbone of agroforestry plantings, but most trees represent a long-term investment. Fruit trees can take three to fifteen years to bear; timber trees usually need to grow twenty or more years before they can be harvested. These and other long-term tree resources are valuable and necessary, but most farmers cannot afford to devote their land entirely to a crop that will not yield for many years. Sequential planting, a practice wherein short-term crops are planted with and eventually replaced by long-term trees, is a system that enables farmers to invest for the future while making a return in the present.
A classic example of sequential planting comes from farmers in Cavite, The Philippines, who have devised ways to subsist and profit off the land while their permanent tree crops become established. There are many local variations, but the basic model results in a rice paddy being converted permanently into coffee, fruit trees, and other perennials:
Sequential Planting in a Multistoried System
Year One: Rice is planted. Pineapple and papaya are interplanted with the rice. Rice is harvested, phased out.
Year Two: Papayas are harvested. Coffee and fruit trees are planted.
Year Three: Pineapples and papayas are harvested.
Year Four: Pineapples and papayas are harvested, phased out. Coffee and fruit trees begin to bear.
Some of the variations of this model increase short and long term profits even more, by incorporating bananas, corn, and other crops. This kind of system gives farmers a return from their land while they invest in long-term perennial tree crops such as fruits or timber.
There are other advantages to sequential planning, including:
- greater efficiency in land use (less land area is fallow while tree crops mature)
- increased efficiency in labor (because crop maintenance can overlap)
- enhanced farm diversity
- increased total yields over time
- greater stability, both environmental and economic
- long-term investment made economically viable through short-term yields
There are many other examples of sequential planting systems from other parts of the world. A few that are widely practiced include:
- Planting long-term timber trees into pasture, coffee, or orchards (some of these systems are sequential; others are designed to be stable over time)
- Planting orchard trees into pineapple fields or annual gardens
- Cultivating annual or short-term crops under forestry plantings until the forest canopy closes (also known as the Taungya system)
Careful planning is necessary to ensure that a sequential planting will be successful. There are a few things to watch out for in particular. One is competition--crops planted together should not have harmful effects on one another, and rooting habits should be understood so plants are compatible and not overly competitive for nutrients and space in the short-term. Planning and advanced study should also determine how long the short-term crop can be expected to bear until the long-term crop takes over by shading or root competition. Marketing of the different crops as they change from year to year is also an important factor to consider. The most effective sequential planting systems are developed over time through experience.
Sequential planting is one of the oldest agricultural practices in the world, and is a viable system for farmers or forest planters who need a short-term return as they invest in long-term tree crops.
In future issues of The Overstory, we'll be covering shade-tolerant understory crops, and ways to stack plants in space for an abundant agroforestry system that involves short and long term crops simultaneously.
- Capistrano, Lyn, J. Durno, I. Moeliono, eds. 1990. Resource Book on Sustainable Agriculture for the Uplands. International Institute of Rural Reconstruction, Philippines. Contains a detailed description of the Cavite sequential planting systems.
- Clarke, W.C. and R.R. Thaman. 1993. Agroforestry in the Pacific Islands: Systems for Sustainability. United Nations University Press, Tokyo.
- Nair, P.K. Ramachandran. 1993. An Introduction to Agroforestry. Kluwer Academic Publishers and International Centre for Research in Agroforestry. The Netherlands. Describes the benefits and pitfalls of the Taungya system and other plantation/crop combinations.
Seed Terminator Technology: A Threat to Our Future?
Normally in The Overstory we focus on solutions, but some news items are so threatening we consider them to be important to highlight. We wanted to bring the following to your attention:
The USDA, in cooperation with large companies, has developed a patented genetic technology (called "Control of Plant Gene Expression") which causes plants to be unable to produce viable offspring. In essence, the DNA of affected plants is programmed so the plant kills its own embryo. The main purpose of the technology is to protect the economic interests of genetically altered plant material, preventing farmers from saving their own seeds from such material. The technology would force farmers to purchase seeds every year, rather than being able to collect and save seeds grown locally. Aside from the ethical issues of creating food/seed dependency for profit, many experts believe that the terminator gene sequence could escape into the wider gene pool, causing sterility in other cultivated crops and even wild plants, resulting in an ecological disaster. To read more about the Terminator Gene Technology and what you can do, visit Rural Advancement Foundation International.
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 #61--Effects of Trees on Soils
- The Overstory #27--Foster Ecosystems
- The Overstory #22--Pioneering
- The Overstory #11--Understory Crops
- The Overstory #3--Weeds as a Resource