Severe food insecurity and hunger have increased in sub-Saharan Africa (SSA) and this has been partly attributed to climate change and soil degradation. It is estimated that more than two-thirds of agricultural land in SSA is severely degraded and that production of major food crops including maize will decline by more than 30% by 2050 due to rising temperatures and changing rainfall patterns. Without innovative solutions, the United Nations Sustainable Development Goals, most of which are underpinned by soil health, and in particular goal number two of eradicating hunger by 2030, will unlikely be achieved, especially in SSA where about 230 million people are currently facing serious food shortages.
The food deficits are anticipated to worsen in future, especially in urban areas (UA), as the demand for food, fibre and feed has been soaring up because of the rapidly increasing human population and changing human diets In SSA, the urban population is projected to double from 298 to 595 million by 2030. Yet economic growth in many developing countries has not been keeping pace with population growth leading to high rates of unemployment.
Consequently, many people including young men and women in urban areas in SSA have been forced to resort to agriculture for their livelihoods, albeit on marginal soils demanding immediate research into alternative soil improvement technologies to halt land degradation and enhance crop yields. In addition, the population rise and the resultant rural-to-urban migration due to incessant droughts, crop failures and economic hardships are driving an unprecedented increase in urban settlements in Zimbabwe, with an inevitable increase in municipal water treatment residual (WTR) production and the associated environmental challenges of disposal.