Synthetic fertilizers have long-term negative effects. They can kill many microorganisms that exist in the soil. These microorganisms typically provide a range of benefits, including converting dead human and plant remains into nutrient-rich organic matter. Additionally, if the synthetic fertilizer is nitrogen or phosphate-based, this may leach into groundwater and create algal blooms. Algal blooms are created by increased nitrate levels and disrupt aquatic ecosystems and cause the death of marine life.
By increasing nitrate levels, synthetic fertilizers also cause plants produced from this soil to have high levels of nitrates that convert to nitrites in the intestines. These nitrites can react with hemoglobin to damage the vascular and respiratory systems that can result in death.1 In the article, we will look at Indigenous “automatic” or “organic” fertilization practices. Here, “automatic” can be defined as a fertilization process that requires no extra machination/energy to enforce it since it is part and parcel of the lifecycle of the farm. “Organic” refers to fertilizers that do not add undue amounts of nutrients to the soil.
Indigenous farmers have developed various techniques to improve or maintain soil fertility: Farmers in Zaachilla, Mexico, use the “organic” method of ant refuse to fertilise high-value crops such as tomatoes and chili.
Additionally, “automatic” methods can be seen in the agrosilvopastoral system in Senegal. The Faidherbia albida tree, as shown in the image to the left, sheds its leaves at the beginning of the wet season, which allows the right amount of light to penetrate for the growth of smaller plants. The fallen leaves act as fertilizer that provides mulch that enriches the topsoil, along with nutritious forage. Livestock that feeds on the leaves of this tree also enrich the soil through their dung.
In a combination of “organic” and “automatic” methods, termite mounds were noticed to be sites that were great for growing sorghum and cowpea by Indigenous peoples in Southern Sudan and Zaire.2