Remediation Strategies That Can Be Adopted to Reclaim Degraded Soils in the Communal Areas of Zimbabwe

Abstract

Over the past decades, cumulative loss of productivity of cropland has been estimated at about 13% at a global scale but this could be even more at a subnational or national scale. In Zimbabwe, the largest (>60%) area is affected by various forms of soil degradation and the communal areas are the worst affected with an annual soil loss that averages 3.3 t ha–1. The soil degradation from farmlands is reflected by the reduction of crop production potential, lower surface water quality and damaged drainage networks. The decline in soil characteristics in Zimbabwe is caused by its inappropriate use, typically for agricultural production in the communal areas. Loss in soil quality is a major threat to “soil security,” and is ubiquitous across the globe in its various forms and at varying magnitudes, depending on the specific demands of people and the inexorably increasing pressures on land. Soil degradation is one of the most important threats facing mankind which not only weakens the productive capability of an ecosystem but also affects overall climate. Soil degradation reduces food security especially at the subnational and national levels in the developing countries as it decreases land’s productive capacity. Therefore, efforts should aim at rehabilitating the degraded soils in order to increase crop productivity. However, the causes and mitigation strategies are unique and depend on specific land use and prevailing climatic conditions. It is prudent to address the issue of soil degradation starting at lower levels like a farm which will then feed into the national grid of soil degradation. Most soils in the communal areas of Zimbabwe are heavily degraded as they have lost their physical, chemical or biological qualities that underpin the web of life, hence low crop productivity. This exposes the communal population to acute food shortage. If no corrective measures are taken, this trend is projected to continue at alarming rates in the future. Therefore, this chapter aims at reviewing possible strategies that can be used to regain the high soil quality status in the communal farmlands of Zimbabwe.