Soil Properties Variability Impact On Agricultural Ecosystem Services In Ibadan City, Nigeria

Abstract

Soil properties exhibit significant spatial and temporal variability, influencing the delivery of Agricultural Ecosystem Services (AES). Variability in physical, chemical, and biological soil characteristics affects crop productivity, water regulation, carbon sequestration, and biodiversity support. Key factors contributing to soil variability include parent material, topography, climate, land use, and management practices. These variations affect soil functions, including nutrient cycling, water retention, and microbial activity, which are crucial for sustainable agricultural production. However, agricultural ecosystem services have been facing a lot of challenges in recent times, especially in and around major traditional cities sharing similar characteristics in the developing world. The challenges range from gradual depletion in biodiversity, soil erosion, soil nutrients and properties depletion, etc., all of which have led to a decline in crop yields. The study, therefore, focused on Ibadan city, which exhibits characteristics of a typical traditional city in Nigeria. The methodology was exclusively based on primary and secondary data which were soil samples and satellite imagery respectively. Landsat ETM+ was acquired to classify the land use/land cover of the city into 4 themes. However, 48 soil samples were taken from the 6 Local Government Areas that constitute the peri urban area of Ibadan city, with 24 samples each from farmland and control plots at a depth of 30cm. The samples were collected in the month of June, 2023 using soil auger and clean pan to prevent contamination, and later subjected to laboratory analysis using the standard protocol. Major soil properties required for agriculture, such as Potential Hydrogen (pH), Nitrogen (N), Potassium (K), and Sodium (Na), were major focus for the analysis because of their importance in agriculture. Descriptive statistics was used to assess the soil properties variability between agricultural and natural ecosystems while the relationship between the two was tested using the Pearson’s Product Moment Correlation. Results therefore showed a vertical and horizontal variation of these elements across the area, which has in one way or the other affected the agricultural ecosystem services in the form of reduction in crop production. It was therefore established that understanding soil variability through advanced soil mapping and remote sensing techniques enables farmers and policymakers to make informed decisions, improving agricultural sustainability while minimizing environmental degradation. Addressing soil property variability is therefore recommended to ensure food security, reduce land degradation, and maintain ecosystem stability.