Soil carbon management practices, knowledge of climate change and CO2 emission of some land use types in Ogbomoso Agricultural Zone, Oyo State, Nigeria

Abstract

The design and implementation of land use management types that would minimize degradation and sustain productivity will require an understanding of the soil dynamic processes that prevail under the different land use types and different ecological zones. This paper investigated four land use types, farmer’s soil management practices, knowledge of climate change and effects of land use types on soil carbon and CO₂ emissions in Ogbomoso Agricultural Zone, south-western Nigeria. Multistage sampling techniques were used to select 200 respondents from five Local Government Areas (LGAs) in 20 villages. Information on socio-economic factors, current cropping practices, knowledge of soil types, properties, climate and crop and soil management history was elicited from the respondents. Soil samples from the various land use system were evaluated, while land use system and CO₂ emission were determined. Data were collected with the use of structured questionnaires and described using frequency counts and percentages while Pearson’s Product Moment Correlation (PPMC) was used to test the existence of relationships between the pairs of variables. Majority of the respondents were married and had basic education. Fertilizer usage was at the following level, inorganic fertilizers (59%), Manure (27%), compost (14%) and 44% of them have used at least compost, manure or inorganic fertilizers once. Forty-six percent (46%) relied on personal observation as source of climate change knowledge while 91% had ploughed their farm once and 55% had burnt their land once. Sex (r = 0.356**), age(r = 0.383**), education (r = 0.265**) and source of climate change knowledge (r = 0.216*) had decisive influence on the knowledge of climate change among the respondents. On average, maize farms across the two LGAs showed SOC stock deficits of 174,296 kg ha^-1 corresponding to an emission of about 639,084.68 kg CO₂e ha^-1. Effective land management practices should be adopted for enhanced carbon sequestration, climate change mitigation, sustained fertility status and increased agricultural productivity.