Malawi has suffered from huge deforestion especially in the last few decades and, as a result, major crises have occurred such as the 2001/2 food crisis. A major and very important benefit of agroforestry such as with macadamia trees is that it enables the land and soil to recover from deforestation. As soon as a tree is established the benefits include:
The root structure of trees physically binds soil which prevents soil erosion, especially during Southern African rainy seasons. Soil erosion by the wind is also reduced, by the trees sheltering the soil surface. The macadamia tree root system is especially good at binding soil because it has a very fibrous surface root system as well as a larger deep root system.
Trees absorb the greenhouse gas carbon dioxide, CO2. As they grow the wood stores carbon from atmosphere and they also benficially produce oxygen, O2, during photosynthesis. This process actively reduces carbon dioxide in the Earth's atmosphere and can mitigate carbon damage caused by CO2 emissions which contributes to global warming and climate change.
Trees inherently provide shade which reduces soil surface temperatures, especially in hot regions such as Malawi where exposed soil receives high levels of direct solar radiation. An immediate consequence of the cooler soil is improved water retention of the soil by redicing evaporation. This then improves soil quality and with well spaced tree planting enables improved farming of other crops planted amongst trees - known as inter-cropping.