Compared To Other Systems
Inga alley cropping is an organic, no-till system.
The main drawbacks of chemical farming are:
- Destruction of the soil’s natural micro-organisms which are needed to keep the soil fertile
- The runoffs cause eutrophication and dead zones. The dead zone in the Gulf of Mexico, caused by runoff from both crops and factory farming of animals, exceeds 6000 square miles1
- The manufacture and use of chemical fertilizers causes carbon emissions
- Pesticides and herbicides are toxic to humans and cause illness and death, particularly in the developing world where precautions are either not well known or cannot be afforded
- Pesticides and herbicides kill wildlife that they are not intended to kill
- Chemicals cost money that the world’s poorest cannot afford
Ploughing releases greenhouse gases. A healthy soil depends on micro-organisms. Ploughing breaks fungal filaments.
Other organic systems
There are other organic systems that can work well in the tropics. The best known is the Forest Gardens approach. In Forest Gardens, a combination of useful plants that work well together are grown in one plot. For example, there may be a level of tall fruit trees, then lower trees or bushes that like some shade (maybe coffee), then vegetables. The different plants have to be selected so that they support each other (rather than compete). Legumes, such as Inga, can be included. This system has been successfully employed, particularly by Trees for the Future2
Both systems have advantages and disadvantages. The special advantages of the Inga system are:
- It is cheaper
- It is simpler
- Requires fewer different resources, just Inga seeds, whereas the forest gardens require a set of the appropriate different plants
- There is less to learn than for Forest Gardens, therefore fewer field instructors needed
- All this means Inga will be easier to roll out in quantity and
- Inga is likely to spread more easily from farmer to farmer
- It is more suitable for larger scale planting of crops like maize
The Forest Gardens may allow for more variety of plants, such as fruit trees, to be in the system and will be better for crops that grow for several years. The Inga system is better suited to annual crops.