Food security impacts of the “4 per Thousand” initiative

Abstract

The “4 per Thousand” (4p1000) initiative of the COP21 in Paris, and the Sustainable Development Goals (SDGs) or the Agenda 2030 of the U.N. were both launched in 2015. The SDG #2 (Zero Hunger) and SDG #13 (Climate Action) of the Agenda 2030 are also in accord with the principal objectives of the 4p1000. Among numerous benefits of enhancing soil organic matter (SOM) content in degraded soils is increase in agronomic productivity and use efficiency of the inputs. The magnitude and nature of the agronomic response to increase in SOM content depend on a range of factors including the initial SOM content, plant nutrient management, soil texture, mineralogical composition, supplementary irrigation and farming/cropping system. Soil factors affecting agronomic response include physical/hydrological properties and plant available water capacity (PAWC), plant nutrients and chemical properties, soil depth and biological properties. Thus, there is a need to develop and standardize methodology to establish the cause-effect relationship between SOM content and agronomic yield based on the data from long-term field experiments. A low SOM content may be a cause of low agronomic productivity, especially in degraded soils managed by resource-poor small land holders who use little or no inputs. There is a strong need for additional research on establishing the threshold or critical limit of SOM content for diverse soils and management systems, as well as to determine if there is any masking effect of fertilizer, irrigation, cover cropping, etc. on the response of crop yield to increase in SOM content.