Categories
Human Effort Planet Care

1: Combining crop growing with forestry

Problem:

Halting deforestation is a global challenge largely due to unsustainable agricultural practices that degrade natural ecosystems. Ninety percent of deforestation is the result of agriculture, with 60% due to the extension of agro-industrial intensive farming (soya, palm oil, corn…), and the remaining 30% caused by small-scale and subsistence farmers. Close to 20% of all carbon emissions result from deforestation and forest degradation.

With slash and burn subsistence agriculture, due to heavy seasonal floods, the exposed soil is washed away, leaving infertile barren soil exposed to the dry season. Farmed hillside sites have to be abandoned after a few years.

Solution:

In 1977, a team led by Canadian forester John G. Bene published a seminal work “Trees, food and people : land management in the tropics” in which Bene coined the word agroforestry. This led to the setting up of an International Council for Research in Agroforestry, now the World Agroforestry Center headquartered in Nairobi, Kenya.

Agroforestry is a land use management system in which smart reforestation goes hand in hand with crops or pastureland. This intentional combination of agriculture and forestry increases biodiversity and reduces erosion. Unlike full-sun fields, vulnerable and contributing to ecosystems degradation, agrofrestry is a way to preserve productive ecosystems and adapt to climate change.

One example of agroforestry has proved successful at the Quesungual Lempira Department, Honduras. Here, the Food and Agriculture Organization of the United Nations (FAO) helped introduce a system incorporating local knowledge consisting of the following steps:

  • Hillside secondary forest were thinned and pruned, leaving individual nitrogen-fixing trees to help reduce soil erosion, maintain soil moisture, provide shade and provide an input of nitrogen-rich organic matter in the form of litter.
  • Maize, a local crop was then planted in rows beside the trees, then harvested, leaving their stalks used for nitrogen-fixing climbing bean plants.
  • Further intercropping was carried out with pumpkin, its large leaves and horizontal growth providing additional shade and moisture retention.
  • Pumpkins do not compete with the beans for sunlight since the latter grow vertically on the stalks.

Another agroforestry application is Taungya, a system originating in Burma. In the initial stages of an orchard or tree plantation, trees are small and widely spaced. The free space between the newly planted trees accommodates a seasonal crop. Instead of costly weeding, the underutilized area provides an additional output and income.

More complex taungyas use between-tree space for multiple crops. The crops become more shade tolerant as the tree canopies grow and the amount of sunlight reaching the ground declines. Thinning can maintain sunlight levels.

J. G. Bene, H.W. Beall, A. Cöté, “Trees, food and people : land management in the tropics,” International Development Research Centre, 1977. Daizy Rani Patish, Ecological basis of agroforestry. CRC Press.2008; Kate Langford, “Turning the tide on farm productivity in Africa: an agroforestry solution,“. World Agroforestry Centre, 8 July 2009.

Discover solution 2: How to make silk without killing silk worms.

Support 366solutions on Patreon and receive the ‘366solutions Insider Newsletter’ with updates on the monthly progress and successes of published solutions.