Three ways of addressing soil degradation

This week I will discuss three different soil recovery techniques that African farmers can implement putting the data findings of the iSDAsoil map into practice. Investing in practices that improve soil quality will in turn increase the water productivity of crops and yields (Erkossa, 2010).

Liquid Nano Clay (LNC)

Desertification vulnerability of Africa (Reich et al., 2001)

Desert Control, have created an innovative technique of LNC, a compound mixture of clay and water, to regenerate degraded soil which have fallen victim to desertification. Desertification is major concern in Africa affecting 46% of the continent (Reich et al., 2001). Using clay to improve soil fertility is not a new idea however conventional practices are labour-intensive and disrupts sequestered carbon and the subterrestrial ecosystems maintaining soil structure (Govaerts et al., 2009). The consistency of LNC means it can be sprayed onto arid soils and percolate down the soil profile and bind to sand grains increasing their surface area allowing better retention of water and nutrients throughout the soil profile. Evidence shows Nano Clay can reduce farmers water consumption by 50% (Olesen et al., 2016). Naturally regenerating arid to arable land generally takes 7 to 10 years but using LNC technology this can be achieved in just 7 hours (Wade, 2015). Estimates suggest the benefits of LNC would last 5 years before needing to reapply the mixture.

Application of LNC in practice (Desert Control, ND)

In Egypt LNC field tests showed a 4x increase in yields. Of course, despite these successful results the high start-up costs of LNC prices out many smallholder farmers across Africa. But as a relatively new start-up from 2017, Desert Control are hopeful in the future they can reduce its cost as production expands increasing access for many to transform unproductive arid land.

Biochar

Biochar top-lit portable kiln (Venter, 2012)

As LNC is only suited to improve sandy soils, I wanted to highlight another innovation which is low tech, suitable for non-sandy soils and available at a lower price. Biochar is a fine-grained charcoal-like stable form of carbon produced by burning organic matter through pyrolysis. During pyrolysis the biomass is burned in zero-oxygen environments therefore producing little to no pollutants. Biochar is highly porous and has a large surface area. These properties improve soil structures, increase water retention and promote microbial activity therefore ultimately increasing crop yields. As well as improving soil fertility, biochar usage would decrease groundwater pollution and could contribute to mitigating climate change by sequestering carbon (Lehmann et al., 2006). The low-cost, small-scale production of biochar could be extremely suitable for many African smallholder farmers to address issues of soil degradation as it can be made on-farm using a top-lit updraft biochar kiln using their own agricultural waste.

Sanitation waste

Similarly, to biochar, human faeces can be used to address soil degradation. Converting human faeces into fertiliser creates a closed-loop system which can contribute to improving WaSH facilities. Sanergy a social enterprise building toilets in Kenyan informal settlements collects sanitation waste produced and converts it into organic fertilizer. Likewise, Loowatt deploys waterless toilets across Madagascar and creates fertilizer as a by-product of the faeces collected. Both companies’ eco-sanitation model not only can improve soil fertility through the fertilizer produced but also creates employment opportunities in the local economies and addresses sanitation problems. The video below shows Loowatt successful operation across Tana. Locals however have expressed concerns over whether farmers will want to buy fertilizer made from human faeces (Thieme, 2017). Therefore, for eco-sanitation to be successful, the negative cultural representations of waste must be addressed.

Video: Loowatt's waterless, value-generating toilets in Madagascar

Each potential soil recovery practice I have discussed has its own set of benefits and challenges. There are plenty more practices which smallholder farmers could use to improve their soil fertility such as agroforestry. It is important to remember that there is no singular solution for all African farmers, the most appropriate solution will depend on the resources available to them and the specific requirements of the environment/crops they produce but this should not delay acting. Fundamentally, any steps African farmers take to improve the soil fertility will in turn address the issues of food and water insecurity.